INDUSTRIAL 

ORGANIC  CHEMISTRY 


ADAPTED  FOR  THE  USE  OF 


MANUFACTURERS,  CHEMISTS,  AND  ALL  INTERESTED  IN 

THE  UTILIZATION  OF  ORGANIC  MATERIALS 

IN  THE  INDUSTRIAL  ARTS. 


BY 

SAMUEL  P.  SADTLER,  PH.D.,  LL.D. 

CONSULTING  CHEMIST;    PROFESSOR   OF   CHEMISTRY    IN  THE  PHILADELPHIA   COLLEGE  OF  PHARMACY  AND 
FORMER  PROFESSOR  OF  ORGANIC  AND  INDUSTRIAL  CHEMISTRY  IN  THE  UNIVERSITY  OF  PENN- 
SYLVANIA ;    PAST  PRESIDENT  OF  THE  AMERICAN  INSTITUTE  OF  CHEMICAL  ENGINEERS. 


FOURTH  EDITION 

(REVISED,  ENLARGED,  AND  RESET) 


PHILADELPHIA : 

J.  B.  LIPPINCOTT  COMPANY. 

LONDON :  5  HENRIETTA  STREET,  COVENT  GARDEN. 

1912. 


Copyright,  1891,  by  SAMUEL  P.  SADTLER. 


Copyright,  1895,  by  SAMUEL  P.  SADTLER. 


Copyright,  1900,  by  SAMUEL  P.  SADTLER. 


Copyright,  1912,  by  SAMUEL  P.  SADTLER. 


All  rights  reserved. 


ELECTROTVPEO  AND  PRINTED  BY  ).  B.  LIPPINCOTT  COMPANY,  PHILADELPHIA,  U.S.A. 


PREFACE  TO  THE  FOURTH  EDITION. 


THAT  over  eleven  years  have  passed  since  the  previous  (third)  edi- 
tion of  this  work  was  issued  has  been  due  to  the  fact  that  the  author 
could  not  free  himself  at  an  earlier  date  from  other  literary  and  pro- 
fessional engagements  sufficiently  to  take  up  the  careful  review  of  the 
field  of  industrial  organic  work  required  for  a  proper  revision  of  this  book. 

Organic  chemical  industries  have  grown  and  developed  greatly  in 
the  meantime,  so  that,  although  the  same  division  of  the  subject-matter 
has  been  retained  as  one  approved  by  experience,  much  new  matter  has 
been  introduced  in  every  chapter  and  many  new  technical  products 
described  and  classified. 

In  some  cases  practically  new  industries  have  developed  or  are  de- 
veloping as  new  possibilities  have  been  found  for  organic  materials,  as 
is  seen  in  the  artificial  silk  industry,  the  by-product  coke-oven,  the  dis- 
placement of  natural  indigo  by  the  synthetic  indigo,  and  similar 
examples.  The  author  has  endeavored  to  present  full  and  accurate 
statements  of  these  new  lines  of  manufacture. 

While,  as  in  previous  revisions,  the  bibliography  and  statistics  have 
been  rewritten  and  brought  down  to  date,  it  has  been  sought,  in  this 
revision,  to  make  the  sections  on  analytical  methods  fuller  for  some  of 
the  industries  and  to  choose  only  such  methods  as  are  in  present  use 
and  have  been  approved  by  the  consensus  of  those  directly  interested 
as  specialists  in  the  several  industries.  At  the  same  time  we  must  recall 
the  fact  that  the  limitations  of  space  have  from  the  beginning  precluded 
the  thought  of  giving  more  than  the  most  necessary  methods,  and  these 
the  author  has  given  in  concise  form.  There  are  numerous  excellent 
analytical  manuals  or  reference  works  on  analysis,  both  of  a  general  kind, 
like  Allen's  Commercial  Organic  Analysis,  and  special  ones  on  almost 
every  separate  industry.  The  titles  of  these  latter  will  be  found  very 
generally  in  the  several  bibliographical  lists  under  the  appropriate 
chapter  headings.  Several  new  tabular  statements  have  been  incor- 
porated and  some  new  tables  for  reference  have  been  inserted  in  the 
Appendix. 

As  in  the  preface  of  the  first  edition,  the  acknowledgments  of  the 
author  are  due  to  his  friend,  Mr.  Louis  J.  Matos,  for  corrections  and 
additions  to  Chapters  XII,  XIII,  and  XIV. 

The  author  hopes  that  both  chemical  students  preparing  for  entrance 
on  practical  work  and  manufacturers  engaged  in  the  development  of 
our  industrial  resources  will  find  assistance  and  benefit  from  the  use  of 
the  book  in  its  revised  form. 

PHILADELPHIA,  April,  1912.  Ul 


295803 


PREFACE  TO  THE  FIRST  EDITION. 


THE  literature  of  Applied  Chemistry  is  reasonably  voluminous.  We 
have  dictionaries  and  encyclopaedic  works  upon  the  subject,  a  series  of 
small  hand-books  for  individual  industries,  and  a  mass  of  technical  journals 
of  both  general  and  special  application.  Works,  however,  in  which  the 
effort  is  made  to  give  within  the  bounds  of  a  single  volume  a  general  view 
of  the  various  industries  based  upon  the  applications  of  chemistry  to  the 
arts  are  much  rarer,  and  especially  is  this  true  of  works  printed  in  the  Eng- 
lish language.  In  German  we  have  Wagner's  "  Chemische  Technologic," 
brought  down  to  date  by  its  present  editor,  Ferd.  Fischer  •  Post's  "  Chem- 
ische Technologic,"  Bolley's  "  Technische-Chemische  Untersuchungen," 
Heinzerling's  "  Technische  Chemie,"  Ost's  "  Chemische  Technologic,"  and 
others ;  in  French,  Payen's  "  Chimie  Industrielle"  and  Girardin's  "  Chimie 
applique"  aux  Arts  Industrials,"  etc. ;  while  in  English  we  have  only  the 
now  antiquated  translations  of  Wagner  and  Payen.  In  speaking  thus,  the 
writer  wishes  to  be  understood  as  referring  only  to  general  works  on  chemical 
technology  of  moderate  size.  The  excellent  "  Dictionary  of  Applied  Chem- 
istry," in  three  volumes,  now  being  published  by  Longmans  &  Co.,  does 
not  therefore  come  into  the  consideration,  for  the  twofold  reason  of  its  size 
and  of  its  encyclopaedic  and  disconnected  method  of  treatment. 

Similarly,  works  which  cover  only  a  single  side  of  the  subject,  like  Allen's 
"  Commercial  Organic  Analysis,"  are  not  referred  to  in  the  above  statement. 

The  author  has  endeavored  within  the  compass  of  a  moderate-sized 
octavo  to  take  up  a  number  of  the  more  important  chemical  industries  or 
groups  of  related  industries,  and  to  show  in  language  capable  of  being  under- 
stood even  by  those  not  specially  trained  in  chemistry  the  existing  conditions 
of  those  industries.  The  present  volume,  it  will  be  noticed,  is  limited  to 
"Industrial  Organic  Chemistry."  This  field,  while  covering  many  very 
important  lines  of  manufacture,  does  not  seem  at  present  to  be  so  well  pro- 
vided for  as  the  inorganic  part  of  the  subject.  A  companion  volume, 
covering  this  other  side  of  industrial  chemistry,  is  in  contemplation. 

In  taking  up  the  several  industries  for  survey,  it  has  been  thought  de- 
sirable first  to  enumerate  and  describe  the  raw  materials  which  serve  as  the 
basis  of  the  industrial  treatment ;  second,  the  processes  of  manufacture  are 
given  in  outline  and  explained  ;  third,  the  products,  both  intermediate  and 
final,  are  characterized  and  their  composition  illustrated  in  many  cases  by 
tables  of  analyses ;  fourth,  the  most  important  analytical  tests  and  methods 


vi  PREFACE. 

are  given,  which  seem  to  be  of  value  either  in  the  control  of  the  processes 
of  manufacture  or  in  determining  the  purity  of  the  product ;  and,  fifth,  the 
bibliography  and  statistics  of  each  industry  are  given,  so  that  an  idea  of  the 
present  development  and  relative  importance  of  the  industry  may  be  had. 

The  author  has  endeavored  in  a  number  of  cases  to  give  a  clearer  picture 
of  the  lines  of  treatment  for  an  industry  by  the  introduction  of  schematic 
views  of  the  several  processes  through  which  the  raw  material  is  carried 
until  it  is  brought  out  as  the  finished  product.  A  number  of  these  dia- 
grams have  been  taken  from  German  and  English  sources,  and  several  have 
been  constructed  by  the  author  specially  for  this  work.  A  list  of  these 
diagrams  will  be  found  appended. 

A  large  number  of  the  illustrations  have  been  drawn  specially  for  this 
work,  and  others  have  been  procured  from  the  best  German  and  American 
sources. 

Frequent  foot  references  are  made  to  authorities  and  sources  of  informa- 
tion, although  this  may  not  have  been  done  in  all  cases.  The  author  has  in 
the  analytical  section  made  frequent  use  of  Allen's  "  Commercial  Organic 
Analysis,"  and  hereby  desires  to  acknowledge  his  special  indebtedness  to 
that  most  valuable  work.  He  has  also  made  frequent  use  of  Wagner's 
"Chemische  Technologic,"  thirteenth  edition,  and  Stohmann  and  KerPs 
"  Angewandte  Chemie."  Besides  these  works  of  a  general  character  he  has 
also  consulted  a  large  number  of  special  works,  the  titles  of  which  will  be 
found  in  the  bibliographical  lists  appended  to  each  chapter. 

The  author  desires  here  to  acknowledge  his  indebtedness  to  the  many 
friends  who  have  aided  him  by  information  and  helped  him  especially  in 
the  collating  of  the  statistics  of  the  several  industries. 

His  special  indebtedness  is  due  to  his  friend  and  former  pupil,  Mr.  Louis 
J.  Matos,  M.E.,  who  aided  him  in  the  completion  of  Chapters  XI.  and  XII., 
and  to  whom  Chapter  XIV.  in  its  entirety  belongs. 

To  his  colleague,  Professor  Henry  Trimble,  of  the  Philadelphia  College 
of  Pharmacy,  he  is  also  indebted  for  information  upon  the  subject  of  Tannin 
and  Dye-woods,  as  treated  in  Chapter  XIII. 

The  original  drawings  made  for  this  work  and  the  index  are  also  due  to 

o  o 

Mr.  L.  J.  Matos. 

The  author  hopes  that  this  work  may  prove  of  some  value  to  those  en- 
gaged in  the  several  lines  of  manufacturing  industry  touched  upon  by  show- 
ing the  chemical  nature  of  the  materials  which  are  handled  by  them,  and  of 
the  change  which  these  materials  undergo  in  the  course  of  treatment  and 
preparation  as  marketable  commodities ;  that  it  may  be  suggestive  to  those 
engaged  in  research  or  invention  in  connection  with  chemistry  ;  and,  lastly, 
that  it  may  be  found  to  possess  some  interest  for  the  general  reader  or  the 
student  of  scientific  or  economic  topics. 

PHILADELPHIA,  August  3,  1891. 


TABLE  OF   CONTENTS. 


CHAPTER  I. 

PETROLEUM   AND    MINERAL   OIL   INDUSTRY.  PAGES 

I. — Raw  Materials   13-18 

1.  Natural  Gas,  13.  2.  Crude  Petroleum,  14-16.  3.  Crude  Paraffin, 
16,  17.  4.  Bitumen  and  Asphalt,  17,  18. 

II.' — Processes  of  Treatment 18-30 

1.  Of  Natural  Gas,  18,  19.  2.  Of  Crude  Petroleum,  19-27.  3.  Of 
Ozokerite  and  Natural  Paraffin,  27.  4.  Of  Natural  Bitumens 
and  Asphalts  and  of  Bituminous  Shales,  28-30. 

III. — Products 30-36 

1  From  Natural  Gas  (a,  Fuel  Gas;  6,  Illuminating  Gas;  c,  Lamp- 
black; and,  d,  Electric-light  Carbons),  30-31.  2.  From 
Petroleum,  31-33.  3.  From  Ozokerite  and  Natural  Paraffin, 
35.  4.  From  Bitumens,  Asphalts,  and  Bituminous  Shales, 
35-36. 

IV.— Analytical  Tests  and  Methods 36-48 

1.  For  Natural  Gas,  36.  2.  For  Petroleum,  36-47.  3.  For  Ozokerite,  47. 
4.  For  Asphalts,  47-48. 

V. — Bibliography  and  Statistics 48-52 

CHAPTER  II. 

INDUSTRY  OF  THE   FATS   AND  FATTY  OILS. 

I. — Raw  Materials  53-64 

1.  Occurrence  of  the  Materials  (a,  Vegetable  Oils,  Fats,  and  Waxes; 
b,  Animal  Oils,  Fats,  and  Waxes),  53-58.  2.  Physical  and 
Chemical  Characters  of  the  Different  Oils  and  Fats,  58i,  59. 
3.  Extraction  of  the  Raw  Materials  and  Purification  of  the 
same,  59-64. 

II. — Processes  of  Treatment 64-79 

1.  Saponification  of  Fats,  64-66.  2.  Practical  Soap-making,  66-73. 
3.  Stearic  Acid  and  Candle  Manufacture,  74-77.  4.  Oleo- 
margarine or  Artificial  Butter  Manufacture,  77.  5.  Glycerine 
Manufacture  (5a,  Nitro-glycerine  and  Dynamite),  77-79. 

III. — Products 79-85 

1.  Purified  Oils,  Fats,  and  Waxes,  and  Products  from  the  same, 
79-81.  2.  Soaps,  81-83.  3.  Candles,  85.  4.  Oleomargarine 
or  Butterine,  83.  5.  Glycerine  and  Nitro-glycerine,  83-85. 


viii  TABLE  OF  CONTENTS. 

PAGES 

IV. — Analytical  Tests  and  Methods 85-95 

1.  For  Oils  and  Fats,  85-91.  2.  For  Soaps,  91-93.  3.  Glycerine, 
94-95. 

V. — Bibliography  and   Statistics 95-102 

CHAPTER  III. 

INDUSTBY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

I. — Raw  Materials  103-111 

1.  Essential  Oils,  103-106.  2.  Resins,  106-108.  3.  Caoutchouc, 
108-110.  4.  Gutta-percha  and  Similar  Products,  110-111. 
5.  Natural  Varnishes,  111. 

II. — Processes  of  Treatment III-IIQ 

1.  Manufacture  of  Perfumes  and  Similar  Products,  111,  112. 
2.  Manufacture  of  Varnishes,  112-115.  3.  Manufacture  of 
Printer's  Ink,  115,  116.  4.  Manufacture  of  Oil-cloth,  Linoleum, 
etc.,  116,  117.  5.  Processes  of  Treatment  of  Caoutchouc  and 
Gutta-percha,  117-119. 

III. — Products • 119-124 

1.  Perfumes,  119.  2.  Varnishes,  119-121.  3.  Printing  Inks,  121. 
4.  Miscellaneous  Products  from  Resins  and  Essential  Oils, 
121,  122.  5.  India-rubber  and  Gutta-percha  Products,  122-124. 

IV. — Analytical  Tests  and  Methods 124-129 

1.  For  Essential  Oils,  124-126.  2.  For  Resins,  127-128.  3.  For 
Varnishes,  128.  4.  For  Caoutchouc  and  Gutta-percha,  128,  129. 

V. — Bibliography  and  Statistics 129-133 


CHAPTER  IV. 

THE  CANE- SUGAR  INDUSTRY. 

I. — Raw  Materials  I33~i37 

1.  The  Sugar-cane,  133.  2.  Sugar-beet,  134-135.  3.  Sorghum 
Plant,  134-136.  4.  The  Sugar-maple,  136. 

II. — Processes  of  Treatment 137-167 

1.  Production  of  Sugar  from  the  Sugar-cane,  137-150.  2.  Produc- 
tion of  Sugar  from  the  Sugar-beet,  150-159.  3.  The  Working 
up  of  the  Molasses,  159-164.  4.  Revivifying  of  the  Bone- 
black,  164-167. 

III. — Products  of  Manufacture 167-171 

1.  Raw  Sugars,  167,  168.  2.  Refined  Sugars,  168.  3.  Molasses  and 
Cane-sugar  Syrups,  168-170.  4.  Miscellaneous  Side-products, 
170,  171. 


TABLE  OF  CONTENTS. 


IX 


PAGES 

IV. — Analytical  Tests  and  Methods 172-182 

1.  Determination  of  Sucrose,  172-174.  2.  Determination  of 
Glucose,  or  Invert  Sugar,  174,  175.  3.  Analysis  of  Com- 
mercial Raw  Sugars,  170-177.  4.  Analyses  of  Molasses  and 
Syrups,  177,  178.  5.  Analyses  of  Sugar-canes  and  Sugar- 
beets  and  Raw  Juices  therefrom,  179.  6.  Analyses  of  Side- 
products,  179-182. 

V. — Bibliography  and  Statistics 182-184 

CHAPTER  V. 

THE  INDUSTRIES  OF  STARCH  AND  ITS  ALTERATION  PRODUCTS. 

I. — Raw  Materials  185-187 

II. — Processes  of  Manufacture 187-195 

1.  Extraction  and  Purifying  of  the  Starch,  187-190.  2.  Manu- 
facture of  Glucose,  or  Grape-sugar,  190-192.  3.  Manufacture 
of  Levulose,  192.  4.  Manufacture  of  Maltose,  192,  193.  5.  Soluble 
Starch,  193.  6.  Manufacture  of  Dextrine,  194.  7.  Manu- 
facture of  Sugar-coloring,  194,  195. 

III. — Products 195-197 

1.  Starch,  195.  2.  Glucose  and  Grape-sugar,  195.  3.  Maltose, 
196.  4.  Dextrine,  196.  5.  Unfermentable  Carbohydrates,  197. 

IV. — Analytical  Tests  and  Methods 197-201 

1.  For  Starch,  197-199.  2.  For  Glucose,  or  Dextrose,  199.  3.  For 
Maltose,  199.  4.  Dextrine,  200.  5.  Commercial  Glucose  and 
Similar  Mixtures  derived  from  Starch,  200,  201. 

V. — Bibliography  and  Statistics 201,  202 

CHAPTER  VI. 

FERMENTATION    INDUSTRIES. 

A. — Nature  and  Varieties  of  Fermentation,  203-208. 

B. — Malt  Liquors  and  the  Industries  connected  therewith. 

I. — Raw  Materials  208-210 

1.  Malt,  208,  209.     2.  Hops,  209,  210.     3.  Water,  210. 

II. — Processes  of  Manufacture 210-218 

1.  Malting  of  the  Grain,  210-212.  2.  Preparation  of  the  Wort, 
212-215.  3.  Boiling  and  Cooling,  215,  216.  4.  Fermentation 
of  the  Wort,  216,  217.  5.  Preservation  of  the  Beer,  218. 

III. — Products 218, 219 

IV. — Analytical  Tests  and  Methods 219-223 

1.  For  Malt,  219,  220.  2.  For  Beer-worts,  220,  221.  3.  For  Beer, 
221-223. 


X  TABLE  OF  CONTENTS. 

C. — The  Manufacture  of  Wine.  PAGES 

I. — Raw  Materials    223-225 

1.  The  Grape,  223,  224.     2.  The  Must,  224,  225. 

II. — Processes  of  Manufacture 225-231 

1.  Fermentation,  225,  226.  2.  Diseases  of  Wines  and  Methods  of 
Treating  and  Improving  them,  226-229.  3.  Manufacture  of 
Effervescing  Wines,  229.  4.  Manufacture  of  Fortified,  Mixed, 
and  Imitation  Wines,  229-231. 

III. — Products . 231-235 

IV. — Analytical  Tests  and  Methods 235-239 


D. — Manufacture  of  Distilled  Liquors,  or  Ardent  Spirits. 

I. — Raw   Materials    239-241 

1.  Alcoholic  Liquids,  239,  240.  2.  Sugar-containing  Raw  Ma- 
terials, 240.  3.  Starch-containing  Eaw  Materials,  240,  241. 

II. — Processes  of  Manufacture 241-251 

1.  Preparation  of  the  Wort,  241,  242.  2.  Fermentation  of  the 
Wort,  or  Saccharine  Liquid,  242-244.  3.  Distillation  of  the 
Fermented  Mash,  or  Alcoholic  Liquid,  244-249.  4.  Rectifying 
and  Purifying  of  the  Distilled  Spirit,  249,  250.  5.  Manu- 
facture of  Alcoholic  Beverages  from  Rectified  Spirit,  250,  251. 

III. — Products 251-255 

1.  Rectified  and  Proof  Spirit,  251.  2.  Alcoholic  Beverages  made 
by  Direct  Distillation  of  the  Fermentation  Products,  251-253. 
3.  Alcoholic  Beverages  made  from  Grain  Spirit  by  Distillation 
under  Special  Conditions,  253.  4.  Liqueurs  and  Cordials,  253, 
254.  5.  Side  products,  255. 

IV. — Analytical  Tests  and  Methods 255, 256 


E. — Bread-making. 

I. — Raw  Materials  257-260 

1.  Flour,   257,   258.     2.  Yeast,  or   Ferment,   259,   260.     3.  Baking- 
powders,  260. 

II. — Processes  of  Manufacture 260,  261 

1.  The  Mixing  of  the  Dough  and  its  Fermentation,  260.    2.  Baking, 
261.     3.  The  Use  of  Chemicals  Foreign  to  the  Bread,  261. 

III. — Products 261-263 

1.  Bread,  261,  262.     2.  Crackers  and  Hard  Biscuit,  263. 

IV. — Analytical  Tests  and  Methods 263-265 

1.  For  the  Flour,  263-265.     2.  For  Bread,  265. 


TABLE  OF  CONTENTS.  xi 

F. — The  Manufacture  of  Vinegar.  PAGES 

I. — Raw  Materials  266, 267 

II. — Processes  of  Manufacture 267-270 

1.  The  Orleans  Process,  267,  268.  2.  The  Quick-vinegar  Process, 
268,  269.  3.  The  Manufacture  of  Malt  Vinegar,  269,  270. 
4.  The  Manufacture  of  Cider  Vinegar,  270.  5.  Pasteur's 
Process  for  Vinegar-making,  270. 

III.— Products 270, 271 

IV. — Analytical  Tests  and  Methods 271,  272 

V. — Bibliography  and  Statistics  for  Fermentation  Industries 272-277 

CHAPTEE  VII. 

MILK    INDUSTRIES. 

I. — Raw  Materials • 278-281 

II. — Processes  of  Manufacture 281-288 

1.  Manufacture  of  Condensed  and  Preserved  Milk,  281.  2.  Of 
Butter,  281-284.  3.  Of  Artificial  Butter  (Oleomargarine), 
284-286.  4.  Cheese-making,  286-288. 

III.— Products    288-293 

1.  Condensed  and  Preserved  Milk,  288,  289.  2.  Butter  and  Butter 
Substitutes,  289,  290.  3.  Cheese,  290,  291.  4.  Milk-sugar, 
291.  5.  Koumiss,  291.  6.  Kephir,  292.  7.  Casein  Prepara- 
tions, 292,  293.  8.  Whey,  293. 

IV. — Analytical  Tests  and  Methods 293-299 

1.  For  Milk,  293-296.  2.  For  Butter,  296-299.  3.  For  Cheese, 
299. 

V. — Bibliography  and  Statistics 300, 301 

CHAPTER  VIII. 

• 

VEGETABLE   TEXTILE   FIBRES. 

I. — General  Characters   302-311 

1.  Cotton  Fibre,  303,  304.  2.  Flax,  305,  306.  3.  Hemp,  306,  307. 
4.  Jute,  307,  308.  5.  Miscellaneous  Vegetable  Fibres,  308, 
309.  6.  Classification  of  the  Vegetable  Fibres,  310,  311. 

INDUSTRIES    BASED    UPON    THE    UTILIZATION    OF    VEGETABLE    FIBRES. 

A. — Paper-making, 

L— Raw  Materials 3II~3I4 

1.  Rags,  311.  2.  Wood-fibre,  312,  313.  3.  Esparto,  313.  4.  Straw, 
313,  314.  5.  Jute,  314.  6.  Manila  Hemp,  314.  7.  Paper-mul- 
berry, 314. 


xii  TABLE  OF  CONTENTS. 

PAGES 

II. — Processes  of  Treatment 314-322 

1.  Mechanical  Preparation  of  the  Paper-making  Material,  314,  315. 

2.  Boiling,  315,  316.   3.  Washing,  316,  317.   4.  Bleaching,  317- 

320.  5.  Beating,  320,  321.    6.  Loading,  Sizing,  Coloring,  etc., 

321.  7.  Manufacture  of  Paper  from  the  Pulp,  321,  322. 

III. — Products    ( Different  Varieties  of  Paper ) 322-325 

IV. — Analytical  Tests  and  Methods 325-327 

1.  Determination   of   the   Nature   of   the    Fibre,    325-327.      2.  De- 
termination   of   the   Nature   of   the    Loading   Materials,    327. 

3.  Determination  as  to  Nature  of  the   Sizing  Materials,  327. 

4.  Determination  of  the  Nature  of  the  Coloring  Material,  327. 

B. — Gun-cotton,  Pyroxyline,  Collodion,  and  Celluloid. 
I. — Raw  Materials 327, 328 

II. — Processes  of  Manufacture 328-331 

1.  Gun-cotton,  328,  329.  2.  Pyroxyline  and  Collodion,  329,  330. 
3.  Celluloid,  330,  331. 

Ill-— Products 331,  332 

1.  Gun-cotton,  331.  2.  Pyroxyline,  331.  3.  Collodion,  332.  4. 
Pyroxyline  Varnishes,  332.  5.  Celluloid,  332. 

IV. — Analytical  Tests  and  Methods 332, 333 

C. — Artificial  Silk. 

I.— Raw  Materials  334, 335 

1.  Nitro-cellulose  or  Chardonnet  Process,  334.  The  Cupram- 
monium  Process,  334.  3.  The  Viscose  Process,  334,  335. 

II. — Processes  of  Manufacture 335, 336 

1.  Spinning  of  the  Artificial  Silk  Filament.  2.  The  Collodion  or 
Chardonnet  Process,  335.  3.  The  Cuprammonium  Process, 
335.  4.  The  Viscose  Process,  336. 

III. — Products     336 

IV. — Analytical  Tests  and  Methods 337 

V. — Bibliography    and    Statistics    of    Vegetable    Fibres    and    their 

Industries  337~34o 

CHAPTER  IX. 

TEXTILE  FIBRES   OF  ANIMAL  ORIGIN. 

I. — Raw  Materials 341-346 

A.  Wool  and  Animal  Hairs,  341-344.     B.  Silk,  344-346. 

II. — Processes  of  Manufacture  and  Treatment 346-350 

A.  Wool. — 1.  Wool-scouring,    346,    347.      2.  Bleaching    of    Wool, 

347,  348. 

B.  Silk.— 1.  Reeling  of  Silk,  348.     2.  Silk-conditioning,  348,  349. 

3.  Silk-scouring,  349,  350. 


TABLE  OF  CONTENTS.  xiii 

PAGES 

III. — Products 350, 351 

A.  Woollen  Products,  350,  351.     B.  Silken  Products,  351. 

IV. — Analytical  Tests  and  Methods 351-353 

V. — Bibliography  and  Statistics 353~355 

CHAPTER  X. 

ANIMAL   TISSUES    AND   THEIR   PRODUCTS. 

A. — Leather  Industry. 

I. — Raw  Materials 356-360 

1.  Animal  Hides  and  Skins,  356,  357.  2.  Tannin-containing  Ma- 
terials, 357-360. 

II. — Processes  of  Manufacture 361-370 

A.  Manufacture  of  Sole-Leather,  361-365.  B.  Upper  and  Harness 
Leathers,  365,  366.  (7.  Morocco  Leather,  366.  D.  Mineral 
Tanning  or  "  Tawing,"  366-369.  E.  Chamois  and  Oil -tanned 
Leather,  369,  370. 

III. — Products 370-372 

1.  Sole-leather,  370.  2.  Upper  and  Harness  Leathers,  370.  3. 
Morocco  Leather,  370,  371.  4.  Enamelled  or  Patent  Leathers,  " 
371.  5.  Russia  Leather,  371.  6.  Chamois  Leather,  371. 
7.  White-tanned  or  "Tawed"  Leather,  371.  8.  Crown 
Leather,  371,  372.  9.  Parchment  and  Vellum,  372.  10. 
Degras,  372. 

IV. — Analytical  Tests  and  Methods 372-376 

1.  Qualitative    Tests    for    the    Several    Tanning    Materials,    373. 

2.  Analysis    of    Liquid    and    Solid    Tanning    Extracts,    374. 

3.  Quantitative    Estimation    of    Tannin,     374,     375.      4.  De- 
termination of  Acidity  of  Tan-liquors,  375,  376. 

B. — Glue  and  Gelatine  Manufacture. 

I. — Raw  Materials 376, 377 

1.  Hides  and  Leather,  376,  377.  2.  Bones,  377.  3.  Fish-bladders, 
377.  4.  Vegetable  Glue,  377. 

II. — Processes  of  Manufacture 377-380 

1.  Manufacture  of  Glue  from  Hides,  377-379.  2.  Manufacture  of 
Glue  from  Leather-waste,  379.  3.  Manufacture  of  Glue  or 
Gelatine  from  Bones,  379,  380.  4.  Manufacture  of  Fish  • 

Gelatine,  380. 

III.— Products 380,  381 

1.  Hide  Glue,  380.  2.  Bone  Glue  (or  Bone  Gelatine),  380,  381. 
3.  Isinglass  (or  Fish  Gelatine),  381.  4.  Liquid  Glue,  381. 

IV.— Analytical  Tests  and  Methods 381, 382 

1.  Absorption  of  Water,  381.  2.  Inorganic  Impurities,  382.  3. 
Adulteration  of  Isinglass  with  Glue,  382. 

V. — Bibliography  and  Statistics  of  Leather  and  Glue  and  Gelatine. .  382-384 


xiv  TABLE  OF  CONTENTS. 

CHAPTER  XL 

INDUSTRIES   BASED   UPON  DESTRUCTIVE  DISTILLATION. 

A. — Destructive  Distillation  of  Wood.  PAGES 

I. — Raw  Materials 385-387 

1.  Composition  of  Wood,  385,  386.  2.  Effect  of  Heat  upon 
Wood,  386,  387. 

II. — Processes  of  Manufacture 387-393 

1.  Distillation  of  the  Wood,  387-389.  2.  Treatment  and  Purifica- 
tion of  the  Crude  Wood-vinegar,  389-392.  3.  Purification 
of  the  Crude  Wood-spirit,  392.  4.  Treatment  of  the  Wood- 
tar,  392,  393. 

III.— Products 393-395 

1.  Pyroligneous  Acid  and  Products  therefrom,  393.  2.  Methyl 
Alcohol  and  Wood-spirit,  393,  394.  3.  Acetone,  394.  4. 
Creosote,  394.  5.  Paraffin,  394.  6.  Charcoal,  394,  395. 

IV. — Analytical  Tests  and  Methods  395~397 

1.  Assay  of  Pyroligneous  Acid  and  Crude  Acetates,  395.  2.  De- 
termination of  Methyl  Alcohol  in  Commercial  Wood-spirit, 

395,  396.      3.  Determination   of   the  Acetone    in   Commercial 
Wood-spirit,  396.    4.  Qualitative  Tests  for  Wood-tar  Creosote, 

396,  397. 


B. — Destructive  Distillation  of  Coal. 

I. — Raw  Materials 397-401 

1.  Varieties  of  Coal,  397-399.     2.  Effects  of  Temperature  in  the 
Distillation  of  Coal,  399-401. 


II. — Processes  of  Treatment  401-415 

I.  Gas-retort  Distillations  of  Coal,  401-405.  2.  Coke-oven  Dis- 
tillation of  Coal,  405-408.  3.  Fractional  Separation  of  Crude 
Coal-tar,  408-411.  4.  Treatment  of  Ammoniacal  Liquor,  411- 
415. 


III. — Products 415-423 

1.  First  Light  Oil,  415-417.  2.  Middle  Oil,  417-419.  3.  Creosote 
Oil  (or  Heavy  Oil),  419-421.  4.  Anthracene  Oil,  421,  422. 
5.  Pitch,  423. 


IV. — Analytical  Tests  and  Methods    423-430 

1.  Valuation  of  Tar  Samples,  423,  424.  2.  Special  Tests  for  Tar 
Constituents,  424-428.  3.  Valuation  of  Ammonia-liquor,  428, 
429.  4.  Analysis  of  Illuminating  Gas,  429,  430. 

V. — Bibliography  and  Statistics  of  Destructive  Distillation  Industries  430-432 


TABLE  OF  CONTENTS.  xv 

CHAPTER  XII. 

THE   ARTIFICIAL   COLORING   MATTERS.  PAGES 

I. — Raw  Materials 433-448 

1.  Hydrocarbons,  433-436.  2.  Halogen  Derivatives,  437,  438.  3. 
Nitro-Derivatives,  438-440.  4.  Amine  Derivatives,  440-443. 

5.  Phenol  Derivatives,   443,  444.     6.  Sulpho-  Acids,  444,  445. 

7.  Pyridine  and   Quinoline  Bases,  445,  446.     8.  Diazo-  Com- 
pounds,  446,   447.     9.  Aromatic    Acids    and    Aldehydes,    447, 
448.     10.  Ketones  and  Derivatives   (Anthraquinone),  448. 

II. — Processes  of  Manufacture 449~455 

1.  Of  Nitrobenzene  and  Aniline,  449-451.  2.  Of  Phenols,  Naph- 
thols,  etc.,  451,  452.  3.  Of  Aromatic  Acids  and  Phthalems, 
452,  453.  4.  Of  Anthraquinone  and  Alizarin,  453,  454.  5.  Of 
Quinoline  and  Acridine,  454.  6.  Sulphonating,  454.  7.  Diazo- 
tizing,  455. 

III. — Products 455-468 

1.  Aniline  or  Amine  Dye-colors,  457-459.  2.  Phenol  Dye-colors, 
459,  460.  3.  Nitroso  and  Oxyazine  Colors,  460,  461.  4.  Azo 
Dye-colors,  461-465.  5.  Quinoline  and  Acridine  Dyes,  465. 

6.  Artificial  Indigo,  465,  466.     7.  Oxyketone  Colors,  466-468. 

8.  The  Sulphur  or  Sulphide  Colors,  468. 

IV. — Analytical  Tests  and  Methods  468-484 

1.  Fastness  of  Colors  to  Light  and  Soap,  469.  2.  Comparative 
Dye-trials,  469-471.  3.  Identification  of  Coal-tar  Dyes,  471- 
473.  4.  Chemical  Analysis  of  Commercial  Dyes,  474.  5.  Ex- 
amination of  Dyed  Fibres,  474-484. 

V. — Bibliography  and  Statistics 485-487 


CHAPTER  XIII. 

NATURAL    DYE-COLORS. 

I. — Raw  Materials 488-497 

A.  Red  Dyes,  488-492.  B.  Yellow  Dyes,  492,  493.  C.  Blue  Dyes, 
493-496.  D.  Green  Dyes,  496,  497.  E.  Brown  Dyes,  497. 

II. — Processes  of  Treatment 497-504 

1.  Cutting  of  Dye-woods,  497.  2.  Fermentation  or  Curing  of 
Dye-woods,  498-500.  3.  Manufacture  of  Dye-wood  Extracts, 
500-502.  4.  Miscellaneous  Processes,  502-504. 

III. — Products 505-511 

1.  From  Red  Dyestuffs,  505-508.  2.  From  Yellow  Dyestuffs, 
508.  3.  From  Blue  Dyestuffs,  508-511.  4.  From  Brown  Dyes, 
511. 


xvi  TABLE  OF  CONTENTS. 

PAGES 

IV. — Analytical  Tests  and  Methods 511-519 

1.  For  Dye-woods,  511-512.  2.  For  Dye-wood  and  other 
Extracts,  512-515.  3.  For  Cochineal,  515.  4.  For  Indigo  and 
its  Preparations,  515-519. 

V. — Bibliography  and  Statistics 519-521 


CHAPTER  XIV. 

BLEACHING,    DYEING,    AND    TEXTILE    PRINTING. 

I. — Preliminary  Treatment  522 

II. — Bleaching  523-529 

1.  For  Cotton,  523-527.     2.  For    Linen,    527,    528.     3.  For    Jute, 
528.     4.  For  Wool,  528,  529.     5.  For  Silk,  529. 

III. — Bleaching  Agents  and  Assistants 529,  530 

IV. — Mordants  Employed  in  Dyeing  and  Printing 530-534 

1.  Mordants  of  Mineral  Origin,  531-533.     2.  Mordants  of  Organic 
Origin,  533,  534. 

V.-Dyeing    534-545 

1.  Cotton-dyeing,  535-541.     2.  Linen-dyeing,  541.     3.  Jute-dyeing, 
541.     4.  Wood-dyeing,  541-544.     5.  Silk-dyeing,  544-545. 

VI. — Printing  Textile  Fabrics 545~557 

VII— Bibliography  557~559 


APPENDIX 
I. — The  Metric  System 561,  562 

II. — Tables  for  Determination  of  Temperature 562-565 

Relations  between  Thermometers,  562.  Thermometric  Equivalents, 
563-565. 

III. — Specific  Gravity  Tables   566-578 

1.  Baumg's  Scale  for  Liquids  Lighter  than  Water,  566.  2.  Com- 
parison of  Various  BaumS  Hydrometers  for  Liquids  Heavier 
than  Water,  567.  3.  Twaddle's  Scale  for  Liquids  Heavier 
than  Water,  568.  4.  Comparison  of  the  Twaddle  Scale  with 
the  Rational  Baume'  Scale,  569.  5.  Comparison  between  Specific 
Gravity  Figures,  Degree  Baum6  and  Degree  Brix,  570-576. 
6.  Table  of  Weight  and  Volume  Relations,  577,  578. 

IV.— Alcohol  Tables   579-584 

V. — Physical  and  Chemical  Constants  of  Fixed  Oils  and  Fats 585, 586 


LIST  OF  ILLUSTRATIONS. 


FIGURE 
1. 

2. 


PAGE 


Lateral  Section  of  Cylindrical 

Oil-still  21 

Vertical  Section  of  Cylindrical 

Oil-still 21 

3.  Oil-still  with  Superheated 

Steam    23 

4.  Still    for    Continuous    Distilla- 

tion,   1 24 

5.  Still    for    Continuous    Distilla- 

tion, II 24 

6.  Commercial    Analysis   of   Crude 

Petroleum    37 

7.  Tagliabue's   Open-cup    Oil-tester  40 

8.  Saybolt's    Open-cup    Oil-tester. .  40 

9.  Abel   Oil-testing  Apparatus....  41 

10.  Heumann    Oil-test    Apparatus.  .  41 

11.  Stoddard    Flash-test   Apparatus  43 

12.  Tagliabue   Cold-test  Apparatus.  43 

13.  Fischer's  Viscosimeter   44 

14.  Engler's  Viscosimeter    44 

15.  Thurston's     Lubricating     0  i  1  - 

tester    45 

16.  Wilson's   Chromometer,   1 47 

17.  Wilson's   Chromometer,   II 47 

18.  Rendering  of  Tallow  by  Steam.  61 

19.  Anglo-American  Seed  Press....  62 

20.  Distillation  of  Free  Fatty  Acids  66 

21.  Wilson  and  Gwynne  Apparatus 

for  Decomposing  Fats 66 

22.  Soap-coppers     69 

23.  WTooden   Soap-frames    72' 

24.  Iron   Soap-frames    72 

25.  Soap-cutting  Machine    73 

26.  Crystallization    of    Solid    Fatty 

Acids    74 

27.  Stearic-acid    Press    74 

28.  Candle-moulding   Frame    76 

29.  Soxhlet   Extractor    86 

30.  Westphal   Specific  Gravity  Bal- 

ance      87 

31.  Boiling   Linseed    Oil    over    Free 

Fire    112 

32.  Boiling  Linseed  Oil  with  Steam  113 

33.  Distillation  of   Copal   and   Am- 

ber Resins    115 

34.  Vessel    for    Vulcanizing    Caout- 

chouc      '. 118 

35.  Three-roll  Sugar-mill   138 

36.  Vacuum-pan    142 

37.  Quadruple   Effect   Evaporator..  143 
b8.  Yaryan     Evaporator     (sectional 

view )     144 

39.  Centrifugal  for  Sugars 146 

40.  Wetzel-pan    147 


FIGURE 


41, 


PAGE 


Sectional  View  of  Sugar  Refin- 
ery   ( full   page ) 149 

42.  Centrifugal  for  Sugar-cones....   151 

43.  Diffusion    Battery — Elevation . .    152 

44.  Diffusion  Battery— Plan   153 

45.  Circular  Diffusion  Battery  (full 

page )     155 

46.  Filter-press    for    Sugar-scums . .    156 

47.  Osmogene     160 

48.  Steffen  Process  for  Molasses . .  .    163 

49.  Char-kiln  for  Sugar  Refineries.    165 

50.  Klusemann  Washer   (full  page)    166 

51.  Polariscope — Scheibler  Form    . .    172 

52.  Payen's  Rendement  Method....    178 

53.  Scheibler's  Apparatus  for  Anal- 

ysis  of    Char 181 

54.  Hoffmann's    Converter    for  Glu- 

cose Manufacture    190 

55.  Maubre's     Converter     for     Glu- 

cose Manufacture    191 

56.  Linter's  Pressure-flask   198 

57.  Varieties  of   Yeast,  after   Han- 

sen   (full  page) 2X)6 

58.  Effect  of  Temperature  upon  Fer- 

mentation    207 

59.  "  Thick-mash  "  Process  for  Beer 

(full   page)     214 

60.  Pasteurizing  Wine  in  Casks. .  .  .   228 

61.  Apparatus  for  Determining  Al- 

coholic Strength    236 

62.  Coffey  Still    (full  page) 245 

63.  Derosne  Still    247 

64.  Savalle  Still   248 

65.  Element  in  Column  Still,  I 248 

66.  Element  in  Column  Still,  II...   248 

67.  Savalle  Rectifying  Column 250 

68.  Aleurometer  of  Boland   264 

69.  Quick-vinegar  Process    269 

70.  Malt  Vinegar  Cask 269 

71.  Laval  Cream  Separator,  1 282 

72.  Laval  Cream  Separator,  II 282 

73.  Fat-cutting    Machine    for    Oleo- 

margarine        284 

74.  Churning-machine   for  Oleomar- 

garine      285 

75.  Cotton   Fibre   Magnified   Thirty 

Times    304 

76.  Cotton     Fibre     Magnified     Two 

Hundred  Times    304 

77.  Sectional    View    of    Stems    and 

Bast   Fibres    305 

78.  Flax    Fibre    under    the    Micro- 

scope        306 

79.  Hemp    Fibre    under   the   Micro- 

scope        306 

xvii 


XV111 


LIST  OF  DIAGRAMS. 


FIGURE  PAGE 

80.  Jute    Fibre    under    the    Micro- 

scope       307 

81.  Manila  Hemp  under  the  Micro- 

scope    .  .  . 307 

82.  China-grass    under    the    Micro- 

scope       309 

83.  Vomiting     Boiler     for     Paper- 

makers    315 

84.  Hollander,   1 310 

85.  Hollander,  II.    (full  page)    ...  318 

86.  Fourdrinier      Machine      (full 

page ) 323 

87.  Nitration  of  Cellulose   in  Cel- 

luloid  Manufacture    330 

88.  Wool   Fibre   under   the   Micro- 

scope        343 

89.  Alpaca  Hair  under  the  Micro- 

scope        343 

90.  Silk    Fibre    under    the    Micro- 

scope         345 

91.  Spinning  of  the  Silk  Cocoon..    345 

92.  Silk-conditioning     349 

93.  Magnified   Section   of  Ox-hide.    356 

94.  Lime-pits  and  Liming  Process 

(full   page)     362 

95.  Unhairing  Machines  and  Wash- 

ing Drums   (full  page) 367 

96.  Revolving    Tumblers    for    Mo- 

rocco-tanning        368 

97.  Vacuum  Pan  for  Glue  Liquor 

Evaporation     378 

98.  Distillation    of    Sawdust    from 

Retorts  389 


FIGURE 


99. 


PAGE 


Tar-condensera    of    Gas-works, 

I     403 

100.  Tar-condensers    of    Gas-works, 

II 403 

101.  Lime-purifiers    of   Gas-works. .  404 

102.  Simon-Carvers   Coke-oven    (full 

page )      406 

103.  Tar-still     409 

104.  Griineberg     and      Blum     Am- 

monia-still       414 

105.  Benzene  Rectification  Column.  416 

106.  Naphthalene     Subliming-cham- 

ber    419 

107.  Anthracene-press     .  . . .; 421 

108.  Sublimation   of   Anthracene...  422 

109.  Manufacture   of   Nitrobenzene.  450 

110.  Horizontal    Aniline-still     451 

111.  Autoclave   for  Alizarin   Manu- 

facture       454 

112.  Madder,  Indigo,  and  Archil...  489 

113.  Cutting  of  Dye-woods 498 

1 14.  Extractor   for   Dye-woods    ....  499 

115.  Cell    of    Dye-wood    Extraction- 

battery     501 

116.  Vacuum-pan  for  Dye-wood  Ex- 

tracts       502 

117.  Indigo  Grinding-mill    505 

118.  Madder    Bleach    523 

119.  Injector-kier 525 

120.  Steaming-chest   for  Turkey-red 

Yarn     540 

121.  Calico  Printing  machine    546 

122.  Steaming   Indigo  Prints 553 


LIST  OF  DIAGRAMS. 


PAGE 

General  View  of  the  Refining  of  Crude  Petroleum 22 

View  of  the  Practical  Utilization  of  a  Fat 67 

Utilization    of    Cotton-seed    and    Products 80 

Outline  for  the  Analysis  of  Fatty  Oils 92 

Leed's  Scheme   for   Soap   Analysis 93 

General  View  of  the  Composition  of  the  Sugar-beet 135 

Outline  showing  the  Production  of  Sugar  from  the  Sugar-cane 139 

Outline  showing  the  Production  of  Sugar  from  the   Sugar-beet 157 

View  of  Products  Obtained  from  Sweet  Milk 281 

Outline  of  Tanning  Process  for  Sole-leather 364 

Qualitative   Tests   for   Tanning  Materials 373 

General  View  of  the  Treatment  of  Wood-tar 390 

General  View  of  the  Products  of  the  Distillation  of  Coal 400 

Scheme  for  the  Distillation  of  Coal-tar 412 

Development  of  Production  Values  from  Coal   by  Distillation 455 

Tables  for  the  Identification  of  Coal-tar  Dyes 471-473 

Tables  for  the  Detection  of  Coloring  Matters  upon  the  Fibre 476-484 

Reactions  of  the  Most  Important  Natural   Dyestuffs 518 

Table  of  Artificial  Dye-colors  which  have  Replaced  or   Compete  with  Natural 

Dyestuffs    556,  557 


INDUSTRIAL  ORGANIC  CHEMISTRY. 


CHAPTER   I. 

PETROLEUM,   MINERAL   OIL,   AND   ASPHALT   INDUSTRY. 


I.  Raw  Materials. 

THE  raw  materials  of  this  industry  are  hydrocarbons  and  products 
derived  from  them  by  alteration,  which  occur  associated  together  in 
nature.  They  may  be  gaseous,  liquid,  or  solid,  and  very  frequently  all 
three  of  these  physical  modifications  are  found  admixed  in  the  same 
crude  material.  As,  on  the  other  hand,  they  occur  at  times  separate  and 
distinct,  they  will  be  separately  noted. 

1.  NATURAL  GAS. — Under  this  name  is  generally  known  now  the 
mixture  of  inflammable  gases  that  is  found  issuing  from  the  earth  in 
various  localities.  While  it  is  chiefly  in  connection  with  the  boring  of 
wells  for  oil  or  salt,  or  as  a  constantly-forming  product  of  decomposi- 
tion in  coal-mines,  that  it  has  been  obtained,  we  find  that  it  often  occurs 
entirely  independently  of  these.  ' '  Burning  springs, ' '  as  they  have  been 
termed,  have  been  known  from  the  earliest  historical  times.  Those  of 
Baku,  on  the  Caspian  Sea,  are  supposed  to  have  been  burning  as  early 
as  the  sixth  century  before  Christ,  and  to  have  been  a  sacred  shrine  of 
the  Persian  fire-worshippers.  The  Chinese  have  employed  natural  gas 
for  centuries  in  their  salt-mines  as  a  source  of  illumination.  In  the 
United  States  it  was  employed  already  in  1821,  at  Fredonia,  New  York, 
as  a  source  of  illumination,  and  for  sixty  years  past  has  served  as  the 
fuel  for  the  evaporation  of  brine  at  the  salt-wells  of  the  Kanawha  Valley, 
West  Virginia. 

The  gas  exists  in  the  porous  rock  reservoirs  under  great  pressure,  900 
Ibs.  per  sq.  inch  closed  pressure  and  38  to  45  Ibs.  open  pressure  having 
been  measured.  Yields  of  15,000,000  cubic  feet  and  in  extreme  cases 
32,000,000  cubic  feet  daily  have  been  attained  in  Ohio  gas  wells.  John 
F.  Carll  estimated  in  1889  that  the  Murrayville  gas  field  in  Western 
Pennsylvania  has  produced  in  four  years  438,000,000,000  cubic  feet, 

13 


14        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 


which  compressed  under  900  Ibs.  (60  atmospheres)  pressure  would  occupy 
a  storage  space  of  7,300,000,000  cubic  feet. 

In  chemical  composition,  natural  gas  is  relatively  uniform.  It  con- 
sists essentially  of  methane  (marsh-gas),  the  first  member  of  the  paraffin 
series  of  hydrocarbons,  which  may  be  accompanied  by  ethane,  propane, 
and  the  members  of  the  paraffin  series  next  following  methane.  Small 
quantities  of  hydrogen,  carbon  monoxide,  and  dioxide  have  been  found 
to  be  present  at  times,  while  nitrogen  is  apparently  an  invariable 
impurity.  The  following  table  gives  the  results  of  analyses  of  natural 
gases,  made  in  1886,  by  Prof.  F.  C.  Phillips  for  the  Second  Geological 
Survey  of  Pennsylvania.  The  localities  chosen  are  all  in  Western 
Pennsylvania,  with  the  exception  of  Fredonia,  New  York,  which  is  intro- 
duced because  of  its  historical  interest: 


J 

oi 

=3 
ft 

fi 

i£ 

3 

fi 

.*iS 

£ 

i-  ti 

M 

6 

6 

6 

£2 

c"S 

^  o 

£ 

S5 

CONSTITUENTS. 

.a.® 

•c  55 

a 

a 

§ 

o> 

a**? 

wl 

gg 

>- 

C-S 

§£ 

S3* 

^  u 

Be 

11 

"c  3 

si 

^  C 

3  c 

r 

02 

|S 

tS  " 

so 

OO 

l4 

«w 

» 

i5 

Paraffin  hydrocarbons 

90.05 

90.64 

90.38 

90.01 

95.42 

97.70 

90.09 

87.27 

84.26 

Olefine  hydrocarbons 
Carbon  dioxide  .    .    . 

0.41 

0.30 

0.21 

0.20 

0.05 

0.20 

Trace. 

0.41 

0.44 

0.02 

Oxveren  . 

Trace. 

Trace. 

Trace. 

Trace. 

Trace. 

Trace. 

Trace. 

Trace. 

Trace. 

Nitrogen     

9.54 

9.06 

9.41 

9.79 

4.51 

2.02 

9.91 

12.32 

15.30 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

With  these  may  be  compared  the  natural  gas  from  two  important 
petroleum-yielding  localities  in  Europe,  viz.,  Pechelbronn,  in  Alsace, 
and  Baku,  on  the  Caspian. 


Pechelbronn 

Pechelbronn 

Pechelbronn 

Baku 

Baku 

I. 

II. 

III. 

I. 

II. 

(Engler.) 

(Bugler.) 

(Engler.) 

(Schmidt.) 

(Schmidt.) 

Methane  .    .    . 

73.6 

68.2 

77.3 

92.49 

93.09 

Olefines     .    .    . 

4.0 

3.4 

4.8 

4.11 

3.26 

Carbon  dioxide 

2.2 

2.9 

3.6 

0.93 

2.18 

Carbon  monoxide 

3.0 

3.7 

3.4 

Hydrogen     .    . 

.   . 

.    • 

0.34 

6.98 

Oxygen     .    .    . 
Nitrogen  .    .    . 

17.2 

4.3 
16.9 

2.0 
9.0 

2.13 

0.49 

100.00 

99.6 

100.10 

100.00 

100.00 

2.  CRUDE  PETROLEUM  (syn.  Erdoel,  Naphtha,  etc.). — Under  this 
heading  is  included  the  liquid  product  which  is  obtained  so  abundantly 
in  various  parts  of  the  earth,  either  issuing  from  the  ground  naturally 


RAW  MATERIALS.  15 

or  gotten  by  the  boring  of  wells  through  the  overlying  rocks  to  the  oil-  • 
bearing  strata.  The  oldest  and  until  recently  the  most  important  petro- 
leum district  of  the  world  is  the  Appalachian  field  of  Western  Penn- 
sylvania, extending  from  Allegany  County,  New  York,  through  Penn- 
sylvania, southwesterly  into  West  Virginia  and  Eastern  Ohio.  While 
the  oils  found  in  this  district  may  differ  considerably  in  gravity,  color, 
and  undoubtedly  in  chemical  composition,  the  differences  are  not  funda- 
mental, and  with  certain  special  exceptions  the  crude  oils  from  various 
localities  are  all  brought  together  by  the  pipe-lines  and  become  mixed 
before  going  to  the  refineries.  None  of  these  Pennsylvania  or  West 
Virginia  oils  contain  any  appreciable  amount  of  sulphur  or  other 
impurity  which  would  require  a  modification  of  the  general  refining 
methods.  The  heavy  oils  of  Franklin  and  Smith's  Ferry,  Pennsylva- 
nia, and  some  few  other  localities  are  so  valuable  for  the  manufacture 
of  lubricating  oils  that  they  are  collected  and  worked  separately. .  The 
Pennsylvania  crude  oil  has  in  general  a  dark  greenish-black  color,  appear- 
ing claret-red  by  transmitted  light,  and  varies  ordinarily  in  specific 
gravity  from  0.782  to  0.850,  or,  as  it  is  frequently  expressed,  from  49° 
B.  to  34°  B.  In  chemical  composition  it  is  essentially  composed  of 
hydrocarbons  of  the  paraffin  series  CnH2n+2,  the  gaseous  and  the  solid 
members  of  the  series  being  alike  held  dissolved  in  the  liquid  ones,  and 
smaller  amounts  of  the  hydrocarbons  of  the  benzene  series  CnH2n-G. 
According  to  Markownikoff,  confirmed  by  Mabery,  Pennsylvania  petro- 
leum also  contains  hydrocarbons  of  a  series  CnH2n,  which  he  termed 
"  naphthenes,"  but  which  are  now  generally  known  as  methylenes. 
Within  recent  years  another  important  field  has  developed,  viz.,  Ohio, 
which  includes  the  two  distinct  districts,  the  Lima  oil  district  and  the 
Macksburg  district.  The  former  is  by  far  the  more  important,  but  the 
product  is  peculiar  in  that  it  contains  sulphur,  and  has  an  offensive 
odor  similar  to  Canadian  crude  oil.  Careful  analyses  made  in  the 
author's  laboratory  have  shown  that  it  contains  on  an  average  0.42  per 
cent,  of  sulphur,  combined  in  relatively  stable  forms  not  decomposed 
by  simple  distillation.*  Reference  will  be  made  to  it  in  speaking  of 
refining  methods.  Within  recent  years  the  extension  of  the  Lima  (or 
Trenton  Limestone)  oil-field  westerly  into  Indiana  has  added  to  the 
production  of  this  grade  of  oil.  The  most  important  localities  in  the 
United  States,  outside  of  the  Pennsylvania  and  Ohio  oil-fields,  are 
Texas  and  California,  in  which  latter  State  a  blackish  petroleum  of 
rather  heavier  consistency  than  Pennsylvania  petroleum  is  found  quite 
abundantly.  This  California  petroleum  is  peculiar  in  containing  nitrog- 
enous bases  of  the  pyridine  and  quinoline  groups,  and  in  leaving,  instead 
Of  paraffin,  an  asphaltic  base  or  residuum. 

The  Texas  oil  differs  radically  from  Pennsylvania  oil  in  being  com- 

*  Mabery  identified  in  Ohio  petroleum  methyl,  ethyl,  normal  propyl,  iso-  and 
normal  butyl,  pentyl,  ethyl-pentyl,  and  hexyl  sulphides  and  later  other  compounds 
of  the  formula  CnH2nS  to  which  he  has  given  the  name  of  "thiophanes." 


16        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 

posed  chiefly  of  methylene  hydrocarbons.  It  does  not  yield  much  burn- 
ing oil  distillate  and  contains  as  much  as  2  per  cent,  of  sulphur,  part  of 
which  exists  as  free  sulphur  in  solution.  The  residue  is  asphaltic. 

Still  more  recent  than  the  Texas  oil  development  is  that  of  the  Mid- 
continent  field,  including  specially  Kansas  and  Oklahoma.  The  oil  from 
this  field  varies  greatly,  and  sometimes  contains  both  an  asphalt  and  a 
paraffin  base. 

Closely  related  to  the  Pennsylvania  and  New  York  oil-fields  is  the 
oil  district  of  Canada.  This  is  in  the  neighborhood  of  Enniskillen,  in 
the  western  section  of  the  province  of  Ontario.  The  Canadian  petro- 
leum, however,  is  distinctly  different  from  that  of  Pennsylvania.  It  is 
darker  in  color,  heavier  in  gravity,  and  is  of  a  very  offensive  odor  on 
account  of  sulphur  impurity,  and  is  therefore  more  difficult  and  expen- 
sive to  refine.  As  before  stated,  it  finds-  a  counterpart  in  the  oil  of  Lima, 
Ohio. 

Second  in  importance  to  the  Pennsylvania  oil-fields,  and  even  more 
prolific  in  the  yield  of  individual  wells,  is  the  Russian  petroleum  district 
of  Baku,  on  the  Caspian.  For  detailed  accounts  of  the  extraordinary 
production  of  these  wells,  the  reader  is  referred  to  Boverton  Redwood's 
"  Petroleum  and  its  Products,"  2nd  ed.,  vol.  i,  p.  7,  or  to  Engler's 
articles  in  Dingier 's  Polytechnisches  Journal,  Bd.  cclx  and  cclxi.  The 
Russian  petroleum  has  a  higher  gravity  than  the  American,  averaging 
0.873,  or  31°  B.,  and  has  been  found  to  be  entirely  different  in  its 
chemical  composition,  consisting  for  the  most  part  of  hydrocarbons  of 
the  series  CnH2H,  isomeric  with  the  olefine  series,  and  called  "  naph- 
thenes. "  As  will  be  seen  later,  this  difference  in  chemical  composition 
involves  a  difference  in  the  refining  results. 

The  most  important  of  the  other  European  petroleum-fields  are  those 
of  Galicia,  which  produce  a  variety  of  oils,  both  light  and  heavy,  either 
accompanying  or  independent  of  the  ozokerite  of  the  region,  those  of 
Hanover,  which  yield  thick  oils,  varying  in  specific  gravity  from  .862  to 
.910,  and  those  of  Alsace,  which  also  yield  oils  predominantly  heavy, 
and  used  chiefly  for  lubricants. 

The  Asiatic  petroleum-fields  are  those  of  Burmah,  which  have  long 
been  known  to  be  very  rich,  and  which,  under  British  control,  will  now 
be  developed,  and  those  of  Rangoon,  in  India,  the  oils  from  which  are 
thick  and  heavy,  yielding  much  lubricating  oil  and  paraffin,  and  those 
of  Japan. 

3.  CRUDE  PARAFFIN. — Under  this  head  may  be  understood  the  more 
or  less  compact  solid  material  which  often  accompanies  crude  petroleum, 
is  deposited  from  it  on  standing,  and  in  some  cases  is  found  in  extensive 
deposits  independently  of  it.  Thus,  a  deposit  of  buttery  consistency 
separates  from  some  crude  oils,  such  as  Bradford  oil,  and  adheres  to  the 
pumping  machinery  and  derrick,  forming  a  crust  which  has  to  be 
scraped  off  from  time  to  time.  The  same  oils  deposit  crude  paraffin  in 
the  pipe-lines,  necessitating  a  periodical  scraping  of  the  interior  of  the 
pipe-lines.  Much  of  the  deposit  which  accumulates  in  the  storage-tanks 
of  crude  oil  is  of  the  same  material. 


RAW  MATERIALS.  17 

More  important,  however,  is  the  occurrence  of  solid  native  paraffin, 
under  the  name  of  "  ozokerite,"  or  earth- wax.  The  best-known  locality 
for  this  native  paraffin  is  Boryslaw,  in  Eastern  Galicia,  although  it  is 
found  also  in  the  Caucasian  oil  district,  and  in  Persia  under  the  name 
of  "  neftgil, "  and  some  years  ago  was  found  in  Southern  Utah,  in  the 
United  States.  In  color  it  varies  from  dark  green  to  black,  and  possesses 
a  lamellar  or  conchoidal  fracture,  according  to  the  variety.  It  fuses 
between  56°  and  74°  C.,  or  even  higher.  In  chemical  composition  it 
does  not  differ  much  from  the  separated  paraffin  of  petroleum  oils. 

4.  BITUMEN  AND  ASPHALT. — We  may  have  liquid  bitumens,  usually 
called  malthas,  and  solid  bitumens,  called  asphalts.  Both  may  be  con- 
sidered as  alteration  products  of  petroleum  hydrocarbons  resulting  from 
evaporation  and  oxidation. 

Maltha  (or  mineral  tar)  was  first  found  at  Bechelbronn,  in  Alsace,  and 
was  studied  by  Boussingault,  who  described  it  as  a  viscid,  tarry  liquid 
of  bituminous  odor  and  a  specific  gravity  of  .966.  It  contains  besides 
hydrocarbons  both  sulphur  and  nitrogen. 

In  the  United  States  malthas  are  found  in  California  in  Kern,  Ven- 
tura, and  Santa  Barbara  Counties,  as  well  as  in  Utah,  Kentucky,  Ten- 
nessee, and  Texas.  Those  from  California,  which  have  been  chemically 
examined,  invariably  contain  some  nitrogen  present  in  the  form  of  basic 
hydrocarbons.  They  also  contain  some  water  and  dissolved  gases. 

The  purest  of  the  solid  bitumens  are  known  sometimes  as  "  glance 
pitch  "  or  "  gum  asphaltum."  Prominent  among  them  is  gilsonite, 
which  is  found  in  the  Uintah  Indian  reservation  in  Wasatch  and  Uintah 
Counties,  Utah.  The  purity  of  this  product  (generally  ninety-eight  per 
cent,  soluble  in  carbon  disulphide)  is  such  that  it  finds  large  applica- 
tion in  the  manufacture  of  varnishes  and  insulating  compounds,  the 
production  being  some  three  thousand  tons  annually. 

Of  solid  asphalts,  those  of  greatest  commercial  importance  are  the 
Trinidad  Lake  asphalt  from  the  Island  of  Trinidad  in  the  West  Indies 
and  the  Bermudez  asphalt  from  Venezuela,  South  America.  The  first  of 
these  contains  in  the  crude  state  39.83  per  cent,  of  bitumen,  33.99  per 
cent,  of  earthy  matter,  9.31  per  cent,  of  vegetable  non-bituminous 
matter,  and  16.87  per  cent,  of  water.  After  refining  the  water  is  elim- 
inated and  the  bitumen  is  raised  to  about  sixty  per  cent.  The  Bermudez 
asphalt  contains  but  2.63  per  cent,  of  mineral  matter  and  over  ninety 
per  cent,  of  bitumen.  The  solid  asphalts  of  California  contain  from 
sixty  to  ninety  per  cent,  of  bitumen,  while  the  mineral  matter  in  most 
cases  is  a  very  pure  silica,  or  in  some  cases  infusorial  earth.  Other  solid 
asphalts,  but  less  valuable,  are  those  of  Cuba  and  Syria,  containing 
some  seventy-five  per  cent,  of  a  hard,  brittle  bitumen. 

Very  important  also  are  the  bituminous  limestones  or  ' '  rock  asphalts  ' ' 
of  Europe.  Among  these  may  be  mentioned  those  of  Seyssel,  France, 
Val  de  Travers  in  the  canton  of  Neufchatel,  Switzerland,  Ragusa  in 
Sicily,  and  Limmer  and  Vorwohle  in  Germany.  These  contain  from 
five  and  three-tenths  to  fourteen  per  cent,  of  bitumen,  and  about  eighty- 

2 


18        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 


six  to  ninety  per  cent,  of  carbonate  of  lime,  and  as  they  are  largely  used 
both  in  this  country  and  in  Europe  in  the  manufacture  of  asphaltic  mix- 
tures or  mastics,  a  table  showing  their  exact  composition  is  given : 


Seyssel, 
France. 

Valde 
Travers, 
Switzerland. 

Ragusa, 
Sicily. 

Limmer, 
Germany. 

Vorwohle, 
Germany. 

Bitumen  

8.15 

10.15 

8.92 

14  30 

5.37 

Calcium  carbonate  .  . 
Magnesium  carbonate  . 
Clay  and  oxide  of  iron  . 
Sand  

91.30 
.10 
.15 

88.40 
.30 
.25 

88.21 
.96 
.91 
.60 

67.00 
1?'.  52 

90.80 
.35 
.59 
2  55 

.10 

.45 

.20 

.45 

.40 

1.18 

.34 

100.00 

100.00 

100.00 

100.00 

100.00 

In  the  United  States  the  most  important  occurrence  of  bituminous 
limestone  is  that  of  Uvalde  County,  Texas,  from  which  is  obtained  the 
product  known  as  ' '  litho-carbon, "  used  in  varnish-making  and  for  insu- 
lating purposes. 

Related  to  the  natural  asphalts  are  also  such  minerals  as  Albertite, 
from  the  Albert  mines  in  New  Brunswick,  and  the  Ritchie  mineral  from 
Ritchie  County,  West  Virginia. 

The  Torbane  mineral,  from  Bathgate,  Scotland,  and  Boghead  coal, 
together  with  bituminous  shales,  also  should  be  noted  here.  They  form 
the  crude  material  for  the  Scotch  paraffin  distillation. 

II.  Processes  of  Treatment. 

1.  OF  NATURAL  GAS. — If  we  refer  to  the  composition  of  natural  gas, 
as  already  stated,  it  will  be  seen  that  it  is  largely  made  up  of  methane 
and  its  homologues,  with  some  nitrogen  as  impurity.  The  defines,  or 
"illuminating  hydrocarbons"  of  ordinary  coal-gas,  are  practically 
absent  in  most  cases.  This  at  once  indicates  quite  clearly  the  value  of 
natural  gas  as  a  fuel  and  its  lack  of  value  in  the  natural  state  for  illu- 
minating purposes.  But  that  it  can  be  readily  converted  into  an  excel- 
lent illuminating  gas  has  been  shown,  and  in  Western  Pennsylvania, 
where  natural  gas  is  abundant,  it  is  being  used  for  illumination  as  well 
as  for  fuel.  To  illustrate  the  treatment  that  is  necessary  for  the  pur- 
pose we  may  describe  the  McKay  and  Critchlow  process,  which  has 
proven  quite  successful  in  practice.  The  apparatus  consists  essentially 
like  the  water-gas  generators  of  a  combustion-chamber  filled  with  coal 
brought  to  a  white  heat  by  an  air-blast  and  a  fixing-ch amber  above 
filled  with  fire-brick,  where  the  gaseous  products  of  the  first  reaction 
combine  with  oil  vapors  to  form  a  permanent  illuminating  gas.  The 
procedure  is  as  follows:  The  fuel  having  been  rendered  thoroughly 
incandescent,  and  the  fire-brick  structure  having  been  heated  to  a  light 
orange  tint,  the  air-blast  is  shut  off,  the  lid  of  the  cupola  closed,  and 
the  gas  outlet  opened.  Natural  gas  is  then  introduced  into  the  ash-pit 


PROCESSES  OF  TREATMENT.  19 

and  forced  up  and  through  the  incandescent  fuel-bed,  depositing  its 
carbon  on  the  surfaces  of  the  fuel  as  decomposition  is  effected,  and 
hydrogen  gas  is  thus  liberated,  which,  passing  up  through  the  open 
chamber,  meets  the  vapors  of  the  hydrocarbon,  which  are  projected  into 
the  chambers  by  means  of  a  steam-  or  gas-injector.  All  of  these  products 
of  decomposition  passing  together  into  the  upper  or  fixing  chamber,  a 
part  of  the  hydrogen  unites  with  the  heavy  hydrocarbons,  producing  the 
lighter  hydrocarbons,  while  an  intimate  mixture  of  all  the  gases  is 
effected,  forming  a  completely  permanent  illuminating  gas,  which  passes 
off  through  the  water-seal,  condensers,  scrubbers,  and  purifiers  to  the 
holder  in  the  ordinary  wray.  Natural  gas  is  used  quite  largely  now  with 
Welsbach  gas-mantles,  and  an  excellent  illumination  is  thus  obtained. 

The  most  recent  industry  based  upon  natural  gas  is  the  compression 
of  the  gas  by  the  aid  of  powerful  compressors  so  as  to  liquefy  the  least 
volatile  portions  and  thus  obtain  a  gasolene  yield,  as  the  great  demand 
for  gasolene  for  automobile,  motor-boat  and  manufacturing  purposes 
has  caused  a  great  demand  for  such  a  light  fraction.  What  is  called 
"casing-head  gas,"  that  obtained  in  pumping  crude  oil,  is  best  adapted. 
The  gas  from  the  deep  wells  of  the  California  oil  field  are  said  to  yield 
three  gallons  of  gasolene  per  1000  cubic  feet  of  gas. 

Natural  gas  is  also  burned  for  the  production  of  a  very  pure  grade 
of  lamp-black.  This  manufacture,  first  carried  out  at  Gambier,  Ohio,  is 
now  introduced  at  various  places  in  the  oil  regions  of  Pennsylvania. 
The  gas  is  burned  from  rows  of  burners  placed  in  such  position  that 
the  flame  impinges  upon  slate  or  metallic  slabs  or  revolving  cylinders, 
and  there  deposits  its  carbon.  In  one  building  at  Gambier,  eighteen 
hundred  burners  have  been  used,  consuming  two  hundred  and  seventy- 
five  thousand  cubic  feet  of  gas  per  twenty-four  hours.  \ 

2.  OF  CRUDE  PETROLEUM. — As  petroleum  has  been  shown  to  be  a 
mixture  of  hydrocarbons  of  different  volatility,  the  first  operation  would 
naturally  be  to  effect  a  partial  separation  of  these  hydrocarbons  by  a 
process  of  fractional  distillation.  But,  in  fact,  simpler  lines  of  treatment 
were  first  tried.  It  was  found  that  crude  oils  spread  out  over  warm 
water  in  tanks  and  exposed  to  the  sun  were  much  improved  in  gravity 
and  consistency.  This  process  was  chiefly  employed  for  the  production 
of  lubricating  oils,  and  the  products  were  called  "  sunned  oils."  This 
was  followed  by  the  application  of  methods  of  partial  evaporation  or 
concentration  in  stills,  either  by  direct  application  of  heat  or  by  the 
use  of  steam  coils,  carefully  avoiding  overheating.  The  products  are  called 
"reduced  oils,"  and  form  the  best  material  for  the  manufacture  of  high- 
grade  lubricating  oils.  They  will  be  referred  to  again.  The  process  to 
which  the  great  bulk  o£  crude  petroleum  is  submitted,  however,  is  that 
of  fractional  distillation  continued  to  the  eventual  coking  of  the  resi- 
due. As  the  most  valuable  of  the  several  distillates  is  that  which  is  to 
be  used  as  illuminating  oil,  the  percentage  of  that  distillate  obtainable 
is  an  important  item  in  an  oil  refinery.  A  normally-conducted  frac- 
tional distillation  of  Pennsylvania  petroleum  will  give  from  thirty-five 
to  fifty-five  per  cent,  of  oil  suitable  for  illuminating  purposes,  and  from 


20        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 


twenty  to  thirty  per  cent,  of  lubricating  oils.  About  1865,  however, 
it  was  found  that  if  during  the  distillation  the  heavy  vapors  were  made 
to  drop  back  upon  the  hot  oil  in  the  still  they  became  superheated  and 
were  decomposed.  This  process  of  destructive  distillation  or  ''crack- 
ing" allowed  of  a  notable  increase  of  the  illuminating  oil  fraction  at 
the  expense  of  the  lubricating  oil.  So  at  present  some  seventy-five  to 
eighty  per  cent,  of  burning  oil  is  obtained,  while  the  residuum  from 
which  the  lubricating  oil  is  gotten  is  reduced  to  six  per  cent. 

A  general  outline  of  the  petroleum  refining  process  as  at  present  con- 
ducted is  presented  in  tabular  form  on  the  accompanying  diagram. 

The  Results  of  a  Normal  Distillation  of  One  Hundred  Cubic  Centimetres  of  Crude  Oils  are 

thus  given  by  Engler  : 


CRUDE  OIL  FROM 

Sp.  gr.  at 

Vs  C. 

Began 
to  boil. 

Came  over 
under  150°  C. 

Between  150°  C. 
and  300°  C. 

Over  300°  C. 

Pennsylvania  (I.) 
Pennsylvania  (II.) 
Galicia  (Sloboda)  . 
Baku  (Bibieybat)  . 
Baku  (Balakhani) 
Alsace  (Pechelbronn) 
Hanover  (Oelheim) 

0.8175 
0.8010 
0.8235 
0.8590 
0.8710 
0.9075 
0.8990 

82°  C. 
74°  C. 
90°  C. 
91°  C. 
105°  C. 
135°  C. 
170°  C. 

21     per  cent. 
31.5  per  cent. 
26.5  per  cent. 
23     per  cent. 
8.5  per  cent. 
3     per  cent. 

38.25  per  cent. 
35       per  cent. 
47       per  cent. 
38       per  cent. 
39.5    per  cent. 
50       per  cent. 
32       per  cent. 

40.75  per  cent. 
33.6    per  cent. 
26.5    per  cent. 
39       per  cent. 
52       per  cent. 
47       per  cent. 
68       per  cent. 

The  Commercial  Results  usually  obtained,  on  the  other  hand,  are  thus  stated  by 

the  same  authority: 


CRUDE  OIL  FROM 

Benzine  and 
volatile  oils. 

Burning  oil, 
first  quality. 

Burning  oil, 
second  quality. 

Residuum. 

10  to  20 

3  to  6 

60  t 

55  t 
35  t 

cot 

40 
27  to  33 

o75 
»65 
345 
o70 
13.5 
5  to  6 

5  to  10 
30  to  40 
55  to  60 
25  to  35 
36 
50  to  60 

4 

10.5 
6  to  6 

The  process  is  generally  divided  into  two  quite  distinct  parts.  The 
benzine  and  burning  oil  distillates  are  run  from  the  same  still,  when  the 
fluid  residuum  is  transferred  to  what  are  usually  called  "tar-stills," 
in  which  the  rest  of  the  distilling  operation  is  conducted. 

The  crude-oil  stills  are  of  two  forms,  the  cylindrical  still,  as  illus- 
trated in  section  in  Figs.  1  and  2,  and  the  "cheese-box  "  still,  although 
the  latter  is  little  used  now.  The  former  consists  of  a  cylinder  of 
boiler-plate,  the  lower  half  being  generally  of  steel,  thirty  feet  in  length 
by  twelve  feet  six  inches  in  diameter.  This  still  is  set  horizontally,  as 
shown  in  the  sectional  view,  in  a  furnace  of  brick-work,  usually  so  con- 
structed that  the  upper  part  of  the  still  is  exposed  to  the  air.  The 
"cheese-box  "  still  has  a  body  and  dome-shaped  top  of  boiler-plate  and 
a  double-curved  bottom  of  steel  plate.  It  is  thirty  feet  in  diameter  and 
nine  feet  in  height,  and  is  set  on  a  series  of  brick  arches.  The  working 
charge  of  the  cylindrical  stills  is  about  seven  hundred  barrels  of  crude 


PROCESSES  OF  TREATMENT. 


21 


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22        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 

oil,  although  more  recently  stills  of  one  thousand  barrels  capacity  have 
been  used.  The  still  is  usually  provided  with  coils  of  steam-pipes,  both 
closed  and  perforated.  The  steam,  issuing  in  jets  from  the  perforated 
pipe,  has  been  found  to  facilitate  distillation  by  carrying  over  mechan- 
ically the  oil  vapors. 

FIG.  1. 


Lateral  vertical  section  of  cylindrical  still. 


The  condensing  apparatus  varies  somewhat  in  the  details  of  its  con- 
struction, but  consists  essentially  of  long  coils  of  pipe  immersed  in  tanks, 
through  which  water  is  kept  flowing.  The  terminal  portions  of  the  con- 
densing pipes  all  converge  and  enter  the  receiving  house  within  a  few 


FIG.  2. 


Transverse  vertical  section  of  cylindrical  still. 

inches  of  each  other.  Near  the  extremity  of  each  a  trap  in  the  pipe  is 
made  for  the  purpose  of  carrying  away  the  uncondensable  vapor.  This 
may  be  allowed  to  escape,  or  is  burned  underneath  the  boilers  or  stills, 
effecting  thereby  a  large  saving  in  fuel.  The  condensing  pipes  generally 
deliver  into  box-like  receptacles,  with  plate-glass  sides,  through  which 
the  running  of  the  distillate  can  be  observed,  and  from  which  test  por- 
tions can  be  taken  from  time  to  time  for  the  proper  control  of  the  process. 


PROCESSES  OF  TREATMENT. 


23 


The  tar-stills  are  usually  of  steel,  cylindrical  in  shape,  holding  about 
two  hundred  and  sixty  barrels,  and  are  set  in  groups  of  two  or  more,  sur- 
rounded by  brick-work.  They  are  either  upright  or  horizontally  placed, 
usage  inclining  now  to  the  latter  position.  Vacuum-stills  have  been  and 
are  still  used  to  some  extent,  especially  in  the  preparation  of  reduced  oils 
for  the  manufacture  of  lubricants  and  products  like  vaseline.  Of  course, 
the  evaporation  in  these  stills  takes  place  rapidly,  and  at  the  lowest  tem- 
perature possible,  insuring  a  fractional  distillation  and  not  a  decom- 
position. If  superheated  steam  be  used,  moreover,  instead  of  direct 
firing,  it  is  possible  to  reduce  oils  to  26°  B.  without  any  production  of 
pyrogenic  products.  A  still  arranged  with  superheated  steam  is  shown 

FIG.  3. 


in  Fig.  3.  Continuous  distillation  has  not  proved  commercially  success- 
ful in  the  United  States.  In  Russia,  on  the  other  hand,  continuous  dis- 
tillation has  been  eminently  successful,  being  especially  suited  to  Baku 
petroleum,  as  the  quantity  of  burning  oil  separated  being  comparatively 
small,  the  residuum  is  not  very  much  less  fluid  than  the  crude  oil.  The 
stills,  each  of  the  capacity  of  four  thousand  four  hundred  gallons,  are 
arranged  in  groups  or  series  of  not  more  than  twenty-five,  as  shown  in 
Figs.  4  and  5,  one  of  which  is  a  front  view,  and  the  other  a  section,  and 
a  stream  of  oil  is  kept  continuously  flowing  through  the  entire  number. 
The  crude  oil,  entering  the  first  still,  parts  with  its  most  volatile  con- 
stituents; passing  into  the  next  still,  has  rather  less  volatile  hydro- 
carbons distilled  from  it ;  and,  finally,  flows  from  the  last  still  in  the  con- 
dition of  residuum,  which  in  Russia  is  termed  astatki,  or  masut.  The 
several  stills  are  maintained  at  temperatures  corresponding  with  the 
boiling-points  of  the  products  to  be  volatilized.  Superheated  steam  is 
used  for  all  the  stills,  the  steam  being  delivered  partly  under  the  oil  and 


24        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 

partly  above  the  level  of  the  oil, — that  is,  in  the  vapor  space  above.  The 
fuel  used  under  all  the  stills  in  Baku  is  petroleum  residuum,  or  astatki. 
To  recur,  now,  to  the  products  of  the  first  rough  distillation  of  crude 
oil,  the  first  fraction,  known  as  the  "benzine  distillate,"  and  amounting 
usually  to  twelve  per  cent,  of  the  crude  oil,  is  redistilled  by  steam  heat  in 
cylindrical  stills,  holding  five  hundred  barrels,  and  is  sometimes  separated 

FIG.  4. 


into  the  following  products:  cymogene,  100°  to  110°  B.  gravity;  rhigo- 
lene,  90°  to  100°  B.  gravity;  gasolene,  80°  to  90°  B.  gravity;  naphtha, 
70°  to  76°  B.  gravity;  benzine,  62°  to  70°  B.  gravity. 

The  time  occupied  in  working  the  charge  is  about  forty-eight  hours. 
The  percentage  of  these  products  varies,  but,  as  a  rule,  amounts  to  about 
twenty-five  per  cent,  of  the  first  three  collectively,  rather  more  than 

FIG.  5. 


twenty-five  per  cent,  of  the  naphtha,  and  about  forty  per  cent,  of  the 
benzine.  The  deodorization  of  the  benzine  which  is  to  be  used  for  solvent 
purposes  in  pharmacy  or  the  arts  is  effected  somewhat  after  the  manner 
to  be  described  under  burning  oils  by  the  action  of  sulphuric  acid.  Only 
the  proportion  of  acid  used  is  much  smaller  and  the  agitation  is  effected 
by  revolving  paddles  instead  of  by  an  air-blast.  One-half  of  one  per 
cent,  is  sufficient  in  this  case.  Other  processes  have  been  proposed  for 
the  deodorization,  such  as  the  use  of  dilute  sulphuric  acid  and  potassium 


PROCESSES  OF  TREATMENT.  25 

permanganate,  followed  by  sodium  hydroxide,  which  oxidize  the  impuri- 
ties and  sweeten  the  product. 

The  treatment  of  the  illuminating  oil  fraction  is  a  more  important 
process.  It  must  be  freed  from  the  empyreumatic  products  resulting 
from  the  distillation,  which  give  it  both  color  and  disagreeable  odor.  To 
effect  this  it  is  subjected  to  a  treatment  with  sulphuric  acid,  washing 
with  water  and  a  solution  of  caustic  soda.  This  operation  is  conducted  in 
tall  cylindrical  tanks  of  wrought  iron,  lined  with  sheet-lead,  which  are 
called  "agitators."  The  bottom  is  funnel-shaped,  terminating  in  a  pipe 
furnished  with  a  stopcock  for  drawing  off  the  refuse  acid  and  soda  wash- 
ings. The  distillate  to  be  treated  must  be  cooled  to  at  least  60°  F.,  and 
before  the  main  body  of  acid  is  added  for  the  treatment,  any  water 
present  must  be  carefully  withdrawn.  This  is  done  by  starting  the 
agitation  of  the  oil  by  the  air-pump  and  introducing  a  small  quantity 
of  acid.  This  is  allowed  to  settle,  and  withdrawn.  The  oil  is  now 
agitated,  and  about  one-half  of  the  charge  of  acid  is  introduced  gradually 
from  above.  The  agitation  is  now  to  be  continued  as  long  as  action  is 
indicated  by  rise  of  temperature,  when  the  dark  "sludge  acid  "  is 
allowed  to  settle,  and  withdrawn.  The  remaining  portion  of  acid  is 
added,  and  a  second  thorough  agitation  takes  place.  The  whole  charge 
of  acid  needed  for  an  average  distillate  is  about  one  and  one-half  to  two 
per  cent.,  or  about  six  pounds  of  acid  to  the  barrel  of  oil.  The  acid,  as 
drawn  off,  is  dark-blue  or  reddish-brown  in  color,  and  is  charged  with 
sulpho-compounds  of  the  hydrocarbons  other  than  paraffins  and  poly- 
merized products,  while  free  sulphur  dioxide  gas  is  present  in  abun- 
dance. The  oil,  after  treatment,  consists  of  the  paraffin  hydrocarbons 
almost  freed  from  impurities.  In  color  it  has  been  changed  to  a  very 
light  straw  shade.  The  oil  is  now  washed  with  water  introduced  through 
a  perforated  pipe  running  around  the  upper  circumference  of  the  tank. 
This  water  percolates  through  the  body  of  the  oil,  removes  the  acid,  and 
is  allowed  to  escape  in  a  constant  stream  from  the  bottom.  When  the 
wash-water  shows  no  appreciable  acid  taste  or  reaction,  the  washing  is 
stopped,  and  about  one  per  cent,  of  a  caustic  soda  solution  of  12°  B.  is  in- 
troduced, and  the  oil  is  again  agitated.  When  this  is  drawn  off,  the  oil  is 
ready  for  the  settling  tanks.  A  washing  with  water  after  the  soda 
treatment  is  sometimes  followed,  but  it  is  not  general.  A  washing  with 
dilute  ammonia  is  also  sometimes  used  to  remove  the  dissolved  sulpho- 
compounds.  The  settling  tanks  are  shallow  tanks,  exposed  to  air  and 
light  on  the  sides,  and  here  any  water  contained  in  the  oil  settles  out, 
and  the  oil  becomes  clear  and  brilliant.  They  are  provided  with  steam- 
coils  for  gently  warming  the  oil  in  cold  weather  to  facilitate  this  separa- 
tion. A  spraying  of  the  finished  oil  to  raise  the  fire-test  by  volatilizing 
a  small  quantity  of  the  lighter  hydrocarbon  present  was  formerly  prac- 
tised at  this  stage,  but  this  result  is  now  obtained  by  "steam-stilling  " 
and  collecting  the  volatile  vapors. 

The  Lima  oil  and  Canadian  oil,  which,  as  before  stated,  contain  sul- 
phur impurity,  cannot  be  refined  and  good  illuminating  oils  obtained 
by  this  simple  treatment  with  acid  and  alkali.  Various  methods  of 


26        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 

treatment  have  been  proposed  and  patented  for  these  oils,  such 'as  the 
alternate  treatment  with  litharge  and  caustic  soda,  distillation  over 
finely-divided  copper  and  iron,  but  the  method  finally  adopted  and  now 
in  successful  use  is  to  distil  over  a  mixture  of  oxides  of  copper  and  lead, 
which  take  up  the  sulphur.  The  oil  is  also  sold  for  fuel  purposes.  This 
latter  utilization  has  been  one  of  great  importance,  and  it  is  employed 
in  all  classes  of  manufacturing  establishments  with  great  success  and 
economy  as  a  substitute  for  solid  fuel.  "With  the  aid  of  injector  burners, 
it  has  been  found  possible  to  use  it  in  smelting  and  annealing  furnaces, 
in  all  kinds  of  forges,  in  burning  brick,  tiles,  and  lime,  and  for  raising 
steam  with  all  forms  of  boilers.  It  is  used  in  these  burners  in  connec- 
tion with  either  steam  or  compressed  air. 

The  residuum  of  the  original  crude-oil  distillation  is,  as  was  said, 
distilled  from  the  "  tar-stills."  The  "first  runnings,  constituting  from 
twenty  to  twenty-five  per  cent.,  will  have  a  gravity  of  38°  B.,  and  are 
returned  to  the  crude-oil  tank  for  redistillation,  or  are  treated  and 
purified  as  burning  oil.  The  paraffin  oil  which  now  runs  over  may  be 
caught  in  separate  lots  as  it  deepens  in  color  and  increases  in  density, 
or  it  may  be  all  received  together  to  be  treated  in  the  paraffin  agitator 
with  acid  and  purified  for  the  separation  of  paraffin  wax.  The  agitator 
in  this  case  must  be  provided  with  steam-pipes,  so  that  its  contents  can 
be  kept  perfectly  liquid,  and  the  charge  of  acid  is  larger,  amounting  to 
three,  four,  or  even  five  per  cent.  The  treatment  includes  the  usual 
washing  with  water  and  soda,  all  at  the  proper  temperature.*  After 
settling,  the  paraffin  oil  goes  to  the  chill-rooms,  where,  by  the  aid  of 
the  ammonia  refrigerating  machines  and  the  circulation  of  cooled  brine, 
the  whole  mass  is  brought  to  a  semi-solid  condition.  This  is  pressed 
between  bagging  by  hydraulic  pressure,  is  filter-pressed,  or  more  gen- 
erally at  present  is  "sweated,"  and  the  refined  heavy  oil  which  drains 
off;  is  collected  as  lubricating  oil.  Its  gravity  should  be  about  32°  B., 
fire-test,  325°  F.,  and  cold  test,  30°  F.  The  press-cake  may  be  broken 
up,  melted,  and  recrystallized,  and  then  submitted  to  still  greater  pressure 
at  a  higher  temperature  (70°  F.)  than  before,  when  it  is  gotten  as 
"  refined  wax."  To  convert  it  into  block  paraffin,  it  must  be  washed 
with  benzine,  pressed,  melted,  and  filtered  through  bone-black  or  other 
filtering  medium,  when  it  is  gotten  perfectly  colorless  and  solidifying  to 
a  hard,  translucent  block.  The  characters  of  paraffin  will  be  referred 
to  farther  on. 

The  distillation  of  residuum  is  continued  until  the  bottom  of  the  still 
becomes  red-hot,  when  yellow  vapors  issue  from  the  tail-pipe,  and  a  dense 
resinous  product,  of  a  light-yellow  color,  and  nearly  solid  consistency, 
distils  over.  This  "yellow  wax  "  contains  anthracene,  chrysene,  picene, 
and  other  higher  pyrogenic  hydrocarbons.  Its  use  at  present  is  to  add 

*  With  the  lubricating  oils  from  certain  crude  petroleums,  it  is  found  advan- 
tageous not  to  wash  after  the  acid  treatment,  but  to  treat  immediately  with  a  strong 
caustic  lye  (of  33°  B.),  and  then  to  wash  as  a  final  step.  This  is  said  to  prevent 
the  emulsifying  of  the  oil  and  water  which  sometimes  takes  place  and  greatly  re- 
tards the  separating  out  of  the  oil. 


PROCESSES  OF  TREATMENT.  27 

it  to  paraffin  oils  to  increase  density  and  lower  cold  test.  Its  chemical 
character  will  be  referred  to  again. 

The  coke  remaining  in  the  tar-still  at  the  end  of  the  process  amounts 
to  about  twelve  per  cent.,  and  is  largely  used  in  the  manufacture  of  elec- 
tric-light carbons.  Reduced  oils  gotten  by  careful  driving  off  of  the  light 
fractions  of  the  crude  petroleum,  without  cracking,  as  stated  above,  are 
of  great  value  as  lubricants.  They  are  generally  made  by  vacuum  dis- 
tillation and  the  use  of  superheated  steam  instead  of  direct  firing.  They 
are  either  brought  into  the  market  at  once,  without  further  treatment, 
or  after  a  bone-black  or  clay  filtration.  This  production  of  filtered  oils 
is  usually  combined  with  the  manufacture  of  vaseline,  or  petrolatum, 
as  it  is  now  known  in  the  United  States  Pharmacopoeia.  Taking  a 
vacuum  residuum  as  the  raw  material,  this  is  melted  and  run  on  to 
filters  of  fine  granular  wrell-dried  bone-black.  The  filters  are  either 
steam-jacketed  or  are  placed  in  rooms  heated  by  steam-coils  to  120°  F. 
or  higher.  The  first  runnings  are  colorless,  and  all  up  to  a  certain 
grade  of  color  go  to  the  manufacture  of  vaseline.  Beyond  that  the 
filtrate  is  known  as  "  filtered  cylinder  stock,"  and  is  used  as  a  lubricant 
exclusively. 

3.  OF  OZOKERITE  AND  NATURAL  PARAFFIN. — The  Galician  ozokerite 
is  in  the  main  a  natural  paraffin,  but  contains  some  oil  in  mechanical 
admixture.  Until  within  ten  to  twelve  years  ago  it  was  worked  exclu- 
sively for  the  production  of  paraffin,  but  now  not  more  than  one-third 
of  the  annual  production  is  so  worked.  The  most  of  it  is  distilled, 
yielding  five  per  cent,  of  benzine,  fifteen  to  twenty  per  cent,  of  illu- 
minating oil,  fifteen  per  cent,  of  "blue  oil,"  and  about  fifty  per  cent, 
of  paraffin.  The  "  blue  oil  "  is  a  buttery-like  mixture  of  heavy  oils  with 
paraffin  crystals,  and  corresponds  to  a  paraffin  oil  as  distilled  from 
petroleum.  It  is  run  into  filter-presses  and  pressed,  first  cold,  and  then 
the  press-cake  broken  up  and  pressed  warm  to  remove  the  adhering  oils. 
If  the  paraffin  scale  so  obtained  is  to  be  worked  up  into  block  paraffin, 
it  is  repeatedly  treated  with  benzine  of  not  over  .785  specific  gravity, 
and  pressed,  then  melted  and  filtered  through  bone-black,  as  before 
described  under  petroleum  paraffin. 

If  the  ozokerite  is  to  be  worked  up  as  a  whole  into  the  wax-like 
product  known  as  Ceresine,  the  operation  may  be  conducted  in  one  of 
two  ways.  The  older  method  was,  after  a  preliminary  melting  of  the 
ozokerite,  to  free  it  from  earthy  impurities,  and  continuing  the  heating 
until  all  water  was  driven  out  of  the  melted  mass,  to  treat  it  with  ten 
per  cent,  of  sulphuric  acid  as  long  as  sulphurous  oxide  was  evolved. 
This  was  followed  by  treatment  with  water  and  soda  solution.  To  more 
thoroughly  separate  out  the  black  carbonaceous  matter  produced  by  the 
action  of  the  sulphuric  acid,  one-half  to  one  per  cent,  of  stearic  acid  is 
added,  and  this  then  saponified  with  caustic  soda.  The  soap  so  formed 
carries  down  all  carbonaceous  matter  with  it,  and  allows  the  ceresine 
to  be  filtered  clear  by  using  filter-paper.  The  product  is  the  Yellow 
Ceresine,  much  resembling  beeswax.  The  White  Ceresine,  resembling 
bleached  beeswax,  is  gotten  by  melting  the  yellow  ceresine  by  the  aid  of 


28        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 

steam,  digesting  it  with  bone-black,  with  frequent  stirring,  and  filtering 
through  paper.  The  newer  method,  more  frequently  followed  now,  is 
to  extract  the  ozokerite  with  benzine  and  ligroine.  The  forms  of  appa- 
ratus devised  for  this  purpose  allow  of  a  complete  exhaustion  of  the 
ozokerite  mass  and  a  subsequent  recovery  of  the  solvent  used  in  the 
extraction. 

The  natural  paraffin  that  separates  spontaneously  from  crude  petro- 
leum, and  accumulates  at  times,  as  before  mentioned,  in  pipe-lines,  etc., 
is  chiefly  used  as  a  basis  for  the  manufacture  of  vaseline  and  similar 
products,  being  melted  and  filtered  through  bone-black,  as  already 
described. 

4.  OF  NATURAL  BITUMENS  AND  ASPHALTS  AND  OF  BITUMINOUS 
SHALES. — The  asphalt  or  solid  bitumen  from  the  Island  of  Trinidad  is 
exported  largely  to  the  United  States,  where  it  is  used  in  the  manu- 
facture of  roofing  materials  and  of  asphalt  pavements.  It  yields  from 
one  and  three-fourths  to  two  and  a  half  per  cent,  of  paraffin  on  dis- 
tillation, and  contains  sulphur  as  an  invariable  constituent.  Efforts 
made  to  manufacture  illuminating  and  other  oils  from  the  asphalt  have 
failed  of  practical  results. 

Within  recent  years  artificial  asphalts  have  been  made  by  a  variety 
of  methods.  As  already  mentioned,  the  California  petroleums  all  seem 
to  have  an  asphaltic  instead  of  a  paraffin  base.  Hence  the  residuum 
from  the  refining  of  California  crude  oils  is  manufactured  into  artificial 
asphalts.  As  much  as  eleven  per  cent,  of  artificial  asphalt  has  been 
obtained  in  practice  from  Ventura  County  petroleum. 

Again,  artificial  asphalts  have  been  made  by  treating  Lima  and 
Oklahoma  oil  residuums  with  a  current  of  heated  air  whereby  a  solid 
tenacious  mass  is  obtained  by  polymerization  and  oxidation.  Byerlite 
and  Sarco  asphalts  are  thus  obtained. 

Still  another  process  consists  of  melting  oil  residuums  with  sulphur 
and  heating  until  a  product  is  obtained  which  becomes  solid  on  cooling, 
while  hydrogen  sulphide  is  set  free.  An  interesting  production  of  arti- 
ficial asphalt  was  that  of  Dr.  W.  C.  Day,  who  distilled  a  mixture  of  fish 
and  pine  wood  and  then  submitted  the  oil  obtained  to  a  second  destruc- 
tive distillation.  The  residuum  left  when  the  distillation  was  carried 
to  about  425°  C.  solidified  to  a  black,  shining  mass,  which  in  physical 
properties  and  chemical  composition  strikingly  resembles  Utah  gilsonite. 

Very  much  more  important  are  the  industries  based  upon  the  dis- 
tillation of  bituminous  shales.  As  these  shales  do  not  contain  either 
liquid  or  solid  hydrocarbons  as  such,  but  much  more  complex  com- 
pounds called  bitumens,  the  distillation  is  exclusively  a  destructive  one, 
and  the  character  of  the  distillation  products  becomes  dependent  upon 
the  conditions  of  the  operation,  temperature  being  the  most  important 
consideration.  The  theory  of  destructive  distillation  will  be  entered 
upon  at  length  later  (see  p.  385),  and  we  will  here  only  say  that  for 
paraffin  and  illuminating  oil  production  the  distillation  is  essentially 
a  low-temperature  one. 

The  material  originally  used  in  Scotland  was  Boghead  coal,  or  the 


PROCESSES  OF  TREATMENT.  29 

Torbane  Hill  mineral  from  Bathgate,  near  Glasgow.,  which  was  exhausted 
in  1872.  This  yielded  thirty-three  per  cent,  of  tar  or  oily  distillate  and 
one  to  one  and  one-half  per  cent,  of  crude  paraffin.  At  present  shales 
are  used  which  furnish  about  thirteen  per  cent,  of  tar.  The  material 
for  the  German  paraffin  production  is  an  earthy  brown  coal,  which, 
when  dry,  is  of  a  light-brownish  or  yellowish  color  and  crumbling  char- 
acter; it  yields  on  an  average  8.1  per  cent,  of  tar  and  .G  per  cent,  of 
paraffin.  The  shales  are  usually  distilled  with  some  steam,  which 
increases  the  amount  of  the  tar,  as  well  as  the  ammonia  from  the 
shale.  The  distillation  may  be  intermittent,  but  in  Scotland  is  now 
carried  on  in  a  continuous  process  by  the  two  methods  devised  by  Hen- 
derson and  by  Young  &  Beilby  respectively,  the  exhausted  shale  being 
dropped  from  the  bottom  of  the  upright  retort  into  a  combustion-chamber 
beneath.  As  the  spent  shale  sometimes  contains  as  much  as  from  twelve 
to  fourteen  per  cent,  of  carbon,  this,  with  the  uncondensed  gas  of  the 
distillation,  suffices  for  fuel.  The  several  products  of  the  distillation 
are  (1)  gas,  which  is  freed  from  gasolene  vapors  by  passing  through 
a  coke  tower,  down  which  heavy  oil  is  trickling;  (2)  watery  or  ammo- 
niacal  liquor,  which  is  obtained  to  the  amount  of  from  sixty  to  eighty 
gallons  per  ton  of  shale,  and  yields  from  fourteen  to  eighteen  pounds 
of  sulphate  of  ammonia  per  ton  worked;  (3)  oily  liquor,  or  tar  proper, 
of  dark  greenish  color,  and  ranging  from  .865  to  .880  in  specific  gravity, 
varying  in  amount  from  thirty  to  thirty-three  gallons  per  ton  of  shale 
used.  This  is  distilled  in  cast-iron  stills  holding  from  two  hundred  to 
two  thousand  gallons,  for  the  purpose  of  purifying  it,  until  only  coke 
amounting  to  from  five  to  ten  per  cent,  of  the  tar  is  left.  The  mixed 
distillates  (the  paraffin  magma  being  added  to  the  others),  according  to 
the  usage  of  the  German  paraffin-works,  are  stirred  with  two  per  cent, 
by  volume  of  caustic  soda  solution  in  order  to  take  up  phenols  and 
' '  creosote, ' '  together  with  other  acid  products ;  the  soda  washings  drawn 
off  below,  and  the  supernatant  liquid,  after  washing  with  water,  is 
agitated  with  five  per  cent,  of  sulphuric  acid.  The  refined  oil  is  now 
fractionally  distilled.  The  first  fraction  (specific  gravity  .60  to  .68)  is  a 
gasolene  used  for  carburetting  illuminating  gas;  the  second  (specific 
gravity  .68  to  .76)  is  naphtha,  used  as  a  solvent;  the  third  (specific 
gravity  .81  to  .82)  is  illuminating  oil;  the  fourth  lubricating  oil  (specific 
gravity  .865  to  .900).  The  next  distillate  solidifies  on  cooling,  yielding 
brown  crystals  of  hard  paraffin,  whose  mother-liquor,  removed  by  a 
filter-press,  is  "blue  oil,"  whence  more  but  soft  crystals  can  be  obtained 
by  artificial  refrigeration.  The  mother-liquid  of  these  is  again  treated 
with  vitriol  and  soda  and  distilled ;  the  earlier  fractions  constitute  heavy 
illuminating  oil,  the  later  lubricating  oil.  The  percentage  of  solid 
paraffin  gotten  from  the  crude  shale  oil  is  from  eleven  to  twelve  and  a 
half  per  cent.  The  shale  oil  does  not  yield  any  product  corresponding 
to  vaseline.  B.  Hiibner,  a  German  paraffin  manufacturer,  believing 
that  the  distillations  of  the  process  just  described  act  injuriously  upon 
the  quantity  and  hardness  of  the  paraffin  obtained,  has  modified  the 
process  as  follows.  He  treats  the  crude  shale  oil  with  sulphuric  acid, 


30        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 

and,  after  the  separation  of  this,  distils  the  oil  over  several  per  cent, 
of  slaked  lime.  After  the  crystallization  of  the  paraffin  from  the  dis- 
tillate, it  is  purified  by  washing  with  shale  oils  and  pressing.  He  thus 
avoids  one  distillation  and  obtains  a  larger  yield  of  paraffin,  distinctly 
harder  in  character  than  the  usual  product. 

In  the  Scotch  shale-works  the  distilled  oil  is  treated  first  with  sul- 
phuric acid  and  then  with  caustic  soda,  as  in  the  purifying  of  petroleum 
oils,  and  then  fractionally  distilled.  These  fractions  are  again  treated 
with  acid  and  alkali  before  being  considered  pure  enough  for  the  market. 
In  some  works  (as  those  at  Broxburn)  continuous  distillation  is  prac- 
tised, so  that  a  set  of  three  boiler  stills  and  two  residue-  or  coking-stills, 
used  together,  can  put  through  thirty-five  thousand  gallons  of  crude  oil 
per  day.  The  solid  paraffin,  by  careful  processes  of  extraction,  can  be 
brought  up  to  twelve  and  a  half  per  'cent. 

HI.  Products. 

1.  FROM  NATURAL  GAS. —  (a)  Fuel  Gas. — The  great  value  of  natural 
gas  as  fuel  for  manufacturing  and  industrial  purposes  has  only  been 
realized  in  recent  years,  and  it  was  rapidly  introduced  as  a  substitute 
for  coal  and  coke.  In  Western  Pennsylvania  and  Ohio,  particularly  in 
Pittsburg  and  its  vicinity,  for  manufacturing  purposes,  it  had  for  a  time 
almost  entirely  displaced  coal  and  coke,  but  its  production  has  reached 
a  maximum,  and  is  now  rapidly  falling  off  despite  the  opening  of  new 
wells.  That  natural  gas,  largely  made  up  of  methane  and  similar  hydro- 
carbons, is  one  of  the  best  of  gaseous  fuels  is  seen  from  the  accompany- 
ing table,  prepared  by  a  committee  of  the  American  Society  of  Mechan- 
ical Engineers: 

Table  showing  Comparative  Effects  of  Different  Gas  Fuels. 

Number  of  cubic  feet  needed 

Heat  units  yielded  by  to  evaporate  100  pounds 

one  cubic  foot.  of  water  at  212°  F. 

Hydrogen 183.1  293 

Water  gas  (from  coke)    153.1  351 

Blast-furnace  gas    51.8  1038 

Carbonic  oxide  178.3  313 

Marsh  gas  571.0                                            93.8 

The  comparison  of  its  work  with  that  accomplished  with  solid  fuel, 
as  carried  out  at  the  works  of  Carnegie  Bros.  &  Co.,  in  Pittsburg,  is  also 
given  by  the  same  committee.  Using  the  best  selected  coal,  and  charging 
the  furnace  in  such  manner  as  to  obtain  the  best  results,  the  maximum 
with  coal  was  nine  pounds  of  water  evaporated  to  the  pound  of  coal  con- 
sumed. "In  making  the  calculations,  the  standard  seventy-six-pound 
bushel  of  the  Pittsburg  district  was  used;  six  hundred  and  eighty-four 
pounds  of  water  were  evaporated  per  bushel,  which  was  60.90  per  cent,  of 
the  theoretical  value  of  the  coal.  When  gas  was  burned  under  the  same 
boiler,  but  with  a  different  furnace,  and  taking  a  pound  of  gas  to  be 
equal  to  23.5  cubic  feet,  the  amount  of  water  evaporated  was  found  to  be 


PRODUCTS.  31 

20.31  pounds,  or  83.40  per  cent,  of  the  theoretical  heat-units  were 
utilized. ' ' 

(6)  Gasolene. — The  production  of  a  light  gasolene  from  "casing-head 
gas  "  has  already  been  alluded  to.  It  is  now  produced  in  Pennsylvania, 
West  Virginia,  Ohio,  and  especially  in  California,  where  the  gas  from 
deep  wells  is  specially  adapted  to  yield  a  considerable  fraction.  The 
product  is  a  very  light  gasolene  (of  85°  to  95°  B.),  and  is  usually 
blended  with  a  heavier  naphtha  to  yield  a  commercial  product. 

(c)  Lamp-Uack. — The  burning  of  natural  gas  so  as  to  cause  separation 
of  carbon,  which  is  then  collected  as  lamp-black,  has  been  referred  to. 
The  lamp-black  so  manufactured  has  been  shown  to  be  of  great  purity. 
It  is  miseible  with  water,  does  not  color  ether,  and  is  free  from  oily 
matter.  A  sample  of  it  analyzed  by  Professor  J.  W.  Mallet,  of  the  Uni- 
versity of  Virginia,  gave  the  following  results:  Specific  gravity  at 
17°  C.,  after  complete  exhaustion  of  air,  1.729.  The  percentage  of 
composition  was  as  follows: 

Carbon 95.057 

Hydrogen  0.665 

Nitrogen    0.776 

Carbon  monoxide  1.378 

Carbon  dioxide 1.386 

Water 0.622 

Ash  (Fe2O,  and  CuO)   0.056 


99.940 

(dy  Electric-light  Carbons. — Still  another  use  for  carbon  from 
natural  gas  is  the  manufacture  of  carbons  for  electric  arc-lights,  the 
purity  of  the  material  making  a  very  pure  and  uniform  carbon  pencil 
possible. 

2.  FROM  PETROLEUM. — The  names  of  commercial  products  obtained 
from  petroleum  have,  of  course,  been  almost  infinitely  varied,  as  each 
manufacturer  has  his  trade  names  for  his  special  products.  We  shall 
only  designate  the  generally-accepted  classes  of  products.  Beginning 
with  the  lightest,  we  have : 

Cymogene,  gaseous  at  ordinary  temperatures,  but  liquefiable  by  cold 
or  pressure.  Boiling-point,  0°  C.  (32°  F.).  Specific  gravity,  110°  B. 
Used  in  the  manufacture  of  artificial  ice. 

Rhigolene,  condensable  by  the  use  of  ice  and  salt.  Boiling-point, 
18.3°  C.  (65°  F.).  Specific  gravity,  0.60°  or  100°  B.  Used  as  an  anaes- 
thetic for  medical  purposes. 

Petroleum  Ether  (Sherwood  oil).— Boiling-point,  40°  to  70°  C. 
Specific  gravity,  .650  to  .660,  or  85°  to  80°  B.  Used  as  a  solvent  for 
caoutchouc  and  fatty  oils,  and  for  carburetting  air  in  gas-machines. 

Gasolene  (canadol). — Boiling-point,  70°  to  80°  C.  Specific  gravity, 
.660  to  .690,  or  80°  to  75°  B.  Used  in  the  extraction  of  oil  from  oil- 
seeds, of  grease  from  raw  wool,  and  in  carburetting  coal-gas. 

Naphtha  (Danforth's  oil).— Boiling-point,  80°  to  100°  C.  Specific 
gravity,  .690  to  .700,  or  76°  to  70°  B.  Used  for  burning  in  vapor-stoves 


32        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 

and  street-lamps,  as  a  solvent  for  resins  in  making  varnishes  and  in  the 
manufacture  of  oil-cloths. 

Ligroine. — Boiling-point,  80°  to  120°  C.  Specific  gravity,  .710  to 
.730,  or  67°  to  62°  B.  For  solvent  purposes  in  pharmacy,  for  burning  in 
sponge-lamps,  and  in  extracting  fat  from  bones. 

Benzine  (deodorized). — Boiling-point,  120°  to  150°  C.  Specific 
gravity,  .730  to  .750,  or  62°  to  57°  B.  Used  as  a  substitute  for  turpen- 
tine, for  cleaning  printers'  type,  and  for  dyers',  scourers',  and  painters' 
use. 

The  three  grades  last  mentioned  are  sometimes  mixed  and  under  the 
commercial  names  of  "  gasolene  "  or  "  naphtha  "  used  for  the  small 
motors  in  naphtha  launches  and  motor  boats  and  in  automobiles. 

The  official  "benzinum  "  of  the  U.  S.  Pharmacopoeia  has  a  specific 
gravity  of  0.638  to  0.660  at  25°  C.,  and  boils  between  45°  and  60°  C. 

Burning  Oil,  or  Kerosene. — The  different  burning  oils  are  known 
often  by  special  names,  of  which  the  number  is  legion,  but  they  are 
graded  by  the  American  petroleum  exporters  chiefly  according  to  the 
standards  of  color  and  fire-test.  The  colors  range  from  pale-yellow 
(standard  white)  to  straw  (prime-white)  and  colorless  (water- white). 
The  fire-tests  (see  p.  40),  to  which  the  commercial  oils  are  mostly 
brought,  are  110°  F.,  120°  F.,  and  150°  F. ;  that  of  110°  going  mainly  to 
the  continent  of  Europe  and  to  China  and  Japan,  and  that  of  120°  to 
England.  An  oil  of  150°  P.,  fire-test,  and  water-white  in  color,  is  known 
in  the  trade  as  "  headlight  oil."  An  oil  of  300°  F.,  fire-test,  and  specific 
gravity  .829,  is  known  as  "mineral  sperm,"  or  "mineral  colza  oil." 
"Pyronaphtha  "  is  a  product  from  Russian  petroleum,  somewhat  similar 
to  mineral  sperm  oil.  It  has  a  specific  gravity  of  .865,  and  fire-test  of 
265°  F. 

Lubricating  oils  from  petroleum  have  assumed  an  importance  which 
is  increasing  every  year.  Some  crude  petroleums,  like  those  of  Franklin 
and  Smith's  Ferry,  Pa.;  Mecca,  Ohio;  Volcano,  W.  Va.,  and  other  local- 
ities, are  natural  lubricating  oils,  requiring  little  or  no  treatment  to  fit 
them  for  use.  The  other  petroleum  lubricating  oils  are  gotten  in  one 
of  two  ways.  Either  by  driving  off  the  light  hydrocarbons  from  the 
crude  oil,  yielding  what  is  called  a  "  reduced  oil  "  (see  p.  27),  or  they 
are  the  oils  gotten  by  distilling  the  petroleum  residuums  in  tar-stills. 

The  lightest  of  the  lubricating  oils,  varying  in  gravity  from  32°  B. 
to  38°  B.,  are  frequently  called  "neutral  oils."  They  are  largely  used 
for  the  purpose  of  mixing  with  animal  or  vegetable  oils,  and  it  is  there- 
fore necessary  that  they  should  be  thoroughly  deodorized,  decolorized, 
and  deprived  of  the  blue  fluorescence  or  "bloom  "  characteristic  of 
petroleum  distillates  that  contain  paraffin.  The  first  two  results  are 
accomplished  by  bone-black  or  clay  filtration,  the  last  in  various  ways, 
such  as  treatment  with  nitric  acid,  addition  of  small  quantities  of  nitro- 
naphthalenes,  etc. 

Heavier  lubricating  oils  are  called  "spindle  "  and  "cylinder  "  oils. 
The  most  important  characters  to  be  possessed  by  these  oils  are  high  fire- 
test,  low  cold-test,  and  a  high  viscosity.  (See  analytical  tests,  p.  36.) 


PRODUCTS.  33 

In  the  matter  of  lubricating  oils  the  Russian  products  are,  it  is  now 
admitted,  distinctly  superior  in  most  respects  to  the  American.  This  is 
because  of  the  entire  difference  in  the  chemical  composition  of  the  two, 
the  hydrocarbons  characteristic  of  the  Russian  oil  being  heavier  and 
showing  less  tendency  to  solidify  at  low  temperatures  than  those  of  the 
American  oils.  The  following  statement  from  Boverton  Redwood  will 
illustrate  this: 

Viscosity  Viscosity    Loss  in  viscosity, 

at  70°  F.          at  120°  F.  per  cent. 

Russian  oil  (sp.  gr.  .913) 1400  166  88 

American  oil   (sp.  gr.  .914) 231  66  71 

Russian  oil   (sp.  gr.  .907 ) 649  135  79 

American  oil   (sp.  gr.  .907) 171  58  66 

Russian  oil    (sp.  gr.  .898) 173  56  67 

American  oil   (sp.  gr.  .891 ) 81  40  50 

Refined  rape  oil  (for  comparison) 321  112  65 

It  is  true  that  the  disproportion  is  chiefly  at  lower  temperatures,  the 
Russian  oil  losing  its  body  relatively  faster  than  the  less  viscous  Ameri- 
can oil. 

Gas  Oils. — Since  the  development  in  recent  years  of  the  Texas  oil 
production  on  a  large  scale,  as  the  yield  of  burning  oil  fraction  is  small, 
much  of  a  product  known  as  "gas  oil  "  (because  of  its  use  for  the  produc- 
tion of  a  rich  oil  gas  by  destructive  distillation)  has  been  made.  This 
is  a  fraction  intermediate  between  the  burning  oils  and  lubricating  oil, 
relatively  thin  and  boiling  between  200°  C.  and  300°  C. 

Paraffin  differs  somewhat  in  its  hardness  and  melting  point  according 
to  the  source  from  which  it  is  derived.  The  petroleum  paraffin  is  manu- 
factured generally  in  three  qualities,  fusing  at  125°  F.  (51.6°  C.),  128°  F. 
(53.3°  C.),  and  135°  F.  (57.3°  C.),  respectively;  paraffin  from  shales 
melts  at  56°  C.,  while  that  from  Rangoon  tar  melts  at  61°  C.  and  that 
from  ozokerite  at  62°  C.  The  harder  varieties  are  bluish-white,  translu- 
cent, and  glassy  on  the  surface,  while  the  softer  varieties  are  alabaster- 
white,  dull  in  lustre  and  only  translucent  when  heated.  The  harder 
varieties  are  resonant.  Paraffin  is  readily  soluble  in  ether,  benzine,  and 
all  light  hydrocarbons,  ethereal  and  fatty  oils  and  carbon  disulphide, 
not  entirely  in  absolute  alcohol;  while  ordinary  alcohol  only  takes  up 
3.5  per  cent,  of  it.  It  mixes  with  stearine,  spermaceti,  and  wax  in  all 
proportions.  Exposed  for  some  time  under  a  slight  pressure  to  a  tem- 
perature below  its  melting  point,  paraffin  wax  undergoes  a  molecular 
change  and  becomes  transparent:  but  upon  a  change  of  temperature,  or 
upon  being  struck,  the  original  translucent  appearance  returns. 

The  official  "paraffinum  "  of  the  U.  S.  Pharmacopoeia  is  stated  to  have 
a  specific  gravity  of  0.890  to  0.905  at  25°  C.,  and  melts  at  from  51.6°  C. 
(125°  F.)  to  57.2°  C.  (135°  F.). 

The  harder  variety  of  paraffin  is  used  chiefly  in  candle-making,  for 
which  purpose,  however,  a  small  proportion  (five  per  cent.)  of  stearic 
acid  must  be  added  to  it  to  prevent  the  softening  and  bending  of  the 
candle.  It  is  also  used  for  finishing  calicoes  and  woven  goods,  to  the 

3 


34        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 

surface  of  which,  it  imparts  lustre.  The  softer  varieties  are  used  for 
mixing  with  wax  and  stearic  acid  in  candle-making,  for  the  preparation 
of  translucent  and  water-proof  paper  of  all  grades,  for  impregnating 
Swedish  matches,  for  the  adulteration  of  ''chewing  gums,"  and,  in  recent 
years,  for  "enfleurage  "  or  extracting  delicate  perfumes  from  flowers. 

Vaseline. — This  product  (petrolatum  of  the  United  States  Phar- 
macopoeia and  unguentum  paraffini  of  the  German  Pharmacopoeia)  may 
be  obtained  from  several  of  the  raw  materials  already  mentioned.  In 
the  United  States,  as  the  name  petrolatum  indicates,  it  is  a  petroleum 
product  and  may  be  called  "  natural  vaseline,"  as  it  is  merely  a  purified 
preparation  of  naturally  existing  petroleum  constituents;  in  Germany, 
and  elsewhere  in  Europe,  it  is  either  extracted  from  other  sources 
(pomade  ozokerine),  or,  as  the  name  unguentum  paraffini  indicates,  it  is 
an  "artificial  vaseline  "  made  by  the  solution  of  paraffin  in  paraffin 
oil.  American  vaseline,  as  made  by  the  Chesebrough  Company  and 
others,  is  gotten  by  taking  a  vacuum  residuum  (see  p.  27)  and,  without 
any  treatment  with  sulphuric  acid  or  other  chemicals,  simply  filtering  it 
through  heated  bone-black.  In  this  way  the  amorphous  character  of 
the  hydrocarbons  is  not  changed  and  no  crystalline  paraffin  is  produced, 
as  would  be  the  case  if  it  were  a  distillation  product,  and,  moreover,  no 
traces  of  sulphonic  acids  can  remain  from  the  acid  treatment  to  inter- 
fere with  its  use  as  a  basis  of  medicinal  ointments.  The  petrolatum  of 
the  United  States  Pharmacopoeia  is  an  unctuous  mass  varying  in  color 
from  yellowish  to  light  amber.  It  is  transparent  in  thin  layers  and  is 
completely  amorphous.  It  has  a  specific  gravity  at  60°  C.  (140°  F.)  of 
from  0.820  to  0.850.  It  melts  at  from  45°  to  48°  C.  (113°  to  118.4°  F.). 

Petrolatum  liquidum  of  the  U.  S.  Pharmacopoeia  is  a  colorless  yel- 
lowish oily  liquid  of  specific  gravity  0.870  to  0.940  at  25°  C. 

The  German  vaseline,  or  unguentum  paraffini,  is  made  by  taking  one 
part  of  ceresine  (paraffinum  solidum)  and  dissolving  it  in  three  parts 
of  a  paraffin  shale  oil,  known  as  "vaseline  oil  "  (paraffinum  liquidum). 
This  artificial  vaselin'e,  as  Engler  and  Bohm  have  shown,*  easily  becomes 
granular  on  chilling,  and  shows  its  composite  nature  moreover  by  readily 
separating  on  distillation  into  ceresine  and  oil.  The  natural  vaseline  has 
greater  homogeneity  and  is  more  viscous,  although  at  high  temperatures 
it  seems  to  absorb  more  oxygen  than  the  artificial  preparation.  At 
temperatures  not  exceeding  30°  C.  the  oxygen  absorption  seems  to  be 
practically  nothing  in  either  case. 

Vaseline  is  largely  used  in  pharmacy  and  medical  practice  as  a  basis 
of  ointments  and  pomades. 

Crude  Fuel  Oil. — Much  of  the  California  and  Texas  oil  which  is  of 
inferior  value  for  refining  is  burned  as  fuel  with  suitable  forms  of 
burners.  The  calorific  value  of  such  crude  petroleums  is  quite  high. 
Poole  (Calorific  Powers  of  Fuels,  2nd  edition,  pp.  251  and  252)  gives 
the  following  values:  Pennsylvania  crude  20736  B.  T.  U.,  Lima,  Ohio, 
crude  21600  B.  T.  U.,  Petrolia,  Canada,  crude  20530  B.  T.  U.,  Baku, 

*  Dingier,  Polytech.  Journal,  262,  p.  468. 


PRODUCTS.  35 

Russia,  20160  B.  T.  U.,  Residuum,  Balacheny  21060  B.  T.  TL,  Galician 
oil  18416  B.  T.  U. 

3.  FROM   OZOKERITE  AND   NATURAL   PARAFFIN.  —  The   character   of 
several  of  the  products  now  obtained  from  Galician  ozokerite,  viz.,  illu- 
minating and  lubricating  oils  and  paraffin,  has  been  sufficiently  described 
under  other  heads.     The  peculiar  product  known  as  Ceresine,  gotten 
from  ozokerite  without  distillation,  remains  to  be  described.    It  resembles 
beeswax  very  greatly  in  appearance,  but  is  of  lower  specific  gravity, 
ranging  from  .915  to  .925,  while  wax  is  from  .963  to  .969.    The  fusing 
point  of  ceresine  varies  from  68°  C.  to  80°  C.    Ceresine,  with  a  fusing 
point  of  over  75°  C.,  shows  a  fracture  and  structure  like  that  of  wax. 
Its  behavior  to  water,  alcohol,  ether,  chloroform,  fatty  and  ethereal  oils 
is  exactly  like  that  of  paraffin.    Ceresine  is  extensively  used  as  a  substi- 
tute for  wax  as  well  as  for  most  of  the  uses  before  given  for  paraffin. 
It  is  commended  especially  for  the  formation  of  matrices  for  galvano- 
plastic  work,  proving  in  this  respect  superior  to  gutta-percha.    It  is  also 
being  used  instead  of  gutta-percha  for  hydrofluoric  acid  bottles. 

4.  FROM   BITUMENS,   ASPHALTS,   AND    BITUMINOUS    SHALES.  —  The 
asphaltic  limestones  of  Europe  (see  p.  18)  furnished  the  earliest  known 
technical  products,  and  they  are  still  worked  extensively  in  the  manu- 
facture of  a  variety  of  useful  substances.     Asphaltic  limestones  con- 
taining from  eight  to  twelve  per  cent,  of  bitumen  when  pulverized  and 
heated  furnish  a  powder  which  by  compression  is  made  to  agglutinate 
and  forms  a  very  satisfactory  surfacing  for  roads,  etc. 

Asphalt  mastic  is  made  in  Europe  by  incorporating  with  the  natural 
asphaltic  limestone  purified  and  softened  bitumens  like  that  of  Trinidad 
in  such  proportion  that  the  resulting  composition,  containing  from 
fifteen  to  twenty  per  cent,  of  bitumen,  is  available  for  asphalt  coating 
purposes. 

Asphalt  Paving  Composition. — In  this  country,  the  solid  asphalts 
like  the  imported  Trinidad  are  first  softened  by  the  incorporating  with 
them  of  petroleum  residuums  or  liquid  asphalts,  and  then  mixed  with 
quartz  sand  and  finely  powdered  rock,  in  such  proportion  that  the  voids 
between  the  grains  of  sand  are  properly  filled.  This  constitutes  the 
asphalt  paving  surface  and  is  spread  with  the  aid  of  a  binder  course  of 
coarser  material  upon  a  cement  substratum. 

From  the  crude  shale  oil,  already  described,  the  following  products 
are  obtained: 

Shale  Oil  Benzine. — Specific  gravity  .665  to  .720,  boiling-point  80°  to 
90°  C.,  is  colorless,  of  ethereal  odor,  and  slightly  peppermint-like  taste. 
It  is  used  somewhat  as  a  cleansing  benzine,  but  mainly  in  the  purifying 
of  the  shale  paraffin. 

Photogene  (shale  naphtha). — Specific  gravity  .720  to  .810,  boiling- 
point  145°  to  150°  C.,  has  a  slight  ethereal  odor  and  peppery  taste.  It 
dissolves  sulphur,  phosphorus,  iodine,  fats,  resins,  caoutchouc,  etc.  It  is 
used  somewhat  for  illuminating  purposes  and  for  dissolving  the  fat  from 
bones  and  bleaching  them  in  the  preparation  of  artificial  ivory. 

Solar  oil  comes  into  the  market,  according  to  Grotowski,  in  two  grades, 


36        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 

known  as  prima  and  secunda  oils,  one  with  specific  gravity  .825  to  .830 
and  a  boiling-point  175°  to  180°  C.,  and  the  other  with  specific  gravity 
.830  to  .835  and  a  boiling-point  195°  to  200°  C.  The  oils  are  of  slight, 
yellowish  color,  and  on  exposure  to  air  and  light  lose  their  free  burning 
qualities,  somewhat  through  the  resinifying  of  the  trace  of  creosote  which 
may  remain  in  them.  The  fire-test  of  the  solar  oil  is  generally  above 
100°  C.,  and  they  are  in  general  both  cheap  and  excellent  burning  oils. 
Paraffin  Oil. — The  paraffin  itself  has  been  described  under  a  previous 
heading.  The  expressed  paraffin  oil  is  used  considerably  as  a  lubricating 
oil,  but  is  of  greatest  importance  for  gas-making.  The  gas  from  this 
paraffin  oil  is  especially  rich  in  illuminating  hydrocarbons  and  is  free 
from  the  ordinary  impurities  of  coal-gas.  It  is  extensively  manufactured 
in  Germany,  in  the  Hirzel  and  Pintsch  forms  of  apparatus,  and  in  Eng- 
land by  the  Pintsch,  Keith,  and  Alexander  &  Patterson  processes,  and 
compressed  for  use  in  railway  carriages,  etc.  Its  characters  will  be 
referred  to  more  especially  under  the  heading  of  illuminating  gases. 

IV.  Analytical  Tests  and  Methods. 

1.  FOR  NATURAL  GAS. — These   are  the   methods  employed   for  the 
analysis  of  all  varieties  of  illuminating  gas,  and  will  be  referred  to  under 
that  heading.     (See  p.  429.) 

2.  FOR  CRUDE  PETROLEUM. — According  to  the  rule  of  the  New  York 
Produce  Exchange,  "crude  petroleum  shall  be  understood  to  be  pure 
natural  oil,  neither  steamed  nor  treated,  free  from  water,  sediment,  or 
any  adulteration,  of  the  gravity  of  43°  to  48°  B."  (0.809  to  0.786  sp.  gr.). 
In  order  to  determine  whether  the  petroleum  is  a  ' '  pure  natural  oil  "  a 
sample  is  subjected  to  fractional  distillation,  each  fraction  being  one- 
tenth  of  the  crude  oil  by  volume,  and  the  density  of  the  several  distillates 
is  determined.     The  regular  gradation  of  the  densities  of  the  fractions 
so  obtained  is  taken  as  a  satisfactory  indication  that  the  oil  is  a  natural 
product. 

To  judge  of  the  commercial  value  of  a  crude  •  petroleum  a  fractional 
distillation  is  also  desirable.  For  this  purpose  Engler's  system  of  dis- 
tillation is  to  be  recommended.  He  uses  a  distillation  flask,  the  shape 
and  dimensions  of  which  in  cubic  centimetres  are  to  be  seen  hi  Fig.  6. 
One  hundred  cubic  centimetres  of  the  oil  are  introduced  into  the  flask 
by  the  aid  of  a  pipette,  and  heat  is  applied.  At  first  wire  gauze  is  inter- 
posed between  the  burner  and  the  flask,  but  afterwards  the  naked  flame 
is  employed,  the  heat  being  so  regulated  that  from  two  to  two  and  a 
half  cubic  centimetres  of  distillate  pass  over  per  minute.  In  this  way 
fractions  differing  from  each  other  in  boiling-point  by  50°,  25°,  or  20°  C. 
can  be  obtained.  As  soon  as  the  requisite  temperature  (150°  C.  for  the 
first  fraction)  is  attained,  the  lamp  is  withdrawn  until  the  temperature 
has  fallen  at  least  20°  C.,  when  the  oil  is  reheated  to  the  boiling-point 
and  again  cooled,  this  process  being  repeated  until  no  more  distillate  is 
obtained.  The  oil  is  then  heated  to  the  next  boiling-point,  and  the  cooling 
and  reheating  process  repeated,  and  so  on.  In  this  way  results  can  be 


ANALYTICAL  TESTS  AND  METHODS. 


37 


obtained  with  not  more  than  a  variation  of  one  per  cent,  even  in  the 
hands  of  different  observers.  In  practice  the  fractions  up  to  150°  C. 
are  added  together  for  the  light  naphtha  or  benzine,  those  between 
150°  C.  and  300°  C.  for  the  burning  oil,  and  those  above  300°  C.  for 
lubricating  oils  and  residuum. 

FIG.  6. 


The  following  method  by  Holde  is  now  used : 
Determination  of  Paraffin  in  Crude  Petroleums. — 
Taking  100  grams  of  crude  petroleum,  in  a  tubulated 
glass  retort,  quickly  distill  off  all  up  to  300°  C.  (ther- 
mometer in  vapor).  Then,  changing  the  receptacle,  collect 
the  remaining  distillate  in  a  weighed  flask,  using  no  con- 
denser, and  continue  without  thermometer  the  distillation 
until  coking  of  the  residue.  By  again  weighing  the  re- 
ceptacle, the  total  weight  of  the  heavy  oil  which  is  distilled 
over  is  determined,  from  which  the  percentage  of  paraffin 
found  can  be  reckoned  back  to  the  original  crude  oil 
taken.  Five  to  ten  grams  of  this  heavy  oil  distillate  is 
then  to  be  dissolved  at  room  temperature,  in  a  mixture  of 
one  part  ether  and  one  part  alcohol,  until  clear  solution  is 
obtained.  Then  cooling  down  with  the  aid  of  an  ice  mix- 
ture until  a  temperature  of  — 20°  C.  is  obtained,  add  so 
much  additional  of  the  mixture  of  alcohol  and  ether,  until 
all  the  oily  portions  remain  dissolved  at  — 20°,  and  only  paraffin  flakes 
are  visible.  These  latter  are  then  to  be  filtered  on  a  small  filter,  sur- 
rounded by  a  cooling  mixture  of  ice  and  salt  kept  at  a  temperature  of 
— 20°,  the  liquid  being  drawn  off  by  connecting  with  a  suction  pump, 
the  separated  paraffin  on  the  filter  being  washed  with  previously  cooled 
alcohol-ether  mixture,  until  no  oily  portion  shows  in  the  washings.  The 
precipitate  is  then  taken  from  the  ice  mixture,  washed  off  of  the  filter 
into  a  tared  glass  dish,  with  the  aid  of  warm  benzine,  the  benzine  being 
then  carefully  evaporated  over  the  water-bath.  If,  on  cooling  the  dish, 
it  is  found  that  the  paraffin  is  of  hard  variety,  it  is  dried  for  fifteen 
minutes  at  105°,  and,  after  cooling  in  the  desiccator,  weighed.  If,  on 
the  other  hand,  the  residue  is  soft  paraffin,  melting  under  45°,  this  is 
best  dried  by  keeping  it  in  a  vacuum  desiccator  at  a  temperature  of  50°, 


38        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 

and  then  weighing.  To  the  weighed  amounts  of  paraffin  so  obtained, 
is  to  be  added,  because  of  the  slight  solubility  of  paraffin  in  the  alcohol- 
ether  mixture,  .2  of  one  per  cent,  when  the  distillate  is  perfectly  liquid, 
.4  per  cent,  in  the  case  of  distillates  which  show  a  separation  of  solid 
material  at  15°,  and  one  per  cent,  in  the  case  of  solid  distillate  masses. 

With  these  corrections,  the  determination  is  regarded  as  accurately 
representing  paraffin  in  crude  oils  and  in  lubricating  oils.  For  such 
petroleums  as  contain  both  paraffin  and  asphalt  base,  the  modification 
made  by  Clifford  Richardson  (Jour.  Soc.  Chem.  Ind.,  May  31,  1902)  is 
to  be  used. 

3.  FOR  PETROLEUM  PRODUCTS. — For  commercial  petroleum  products, 
which  are,  of  course,  mixtures  of  hydrocarbons,  the  boiling-point  becomes 
of  only  secondary  importance,  while,  with  reference  to  their  uses  as  illu- 
minants,  the  element  of  safety  comes  "into  consideration,  so  that  what  is 
called  "flash  point  "  and  "burning  point,"  together*mcluded  in  what  is 
known  as  "fire-test,"  becomes  important.  For  lubricating  oils,  the  con- 
sistency or  body  determined  in  the  viscosity-test  and  the  "cold-test,"  or 
point  to  which  they  can  be  chilled  without  separating  paraffin,  is  im- 
portant. For  paraffin  and  solid  products  the  melting-point  and  amount 
of  oil  enclosed  are  important.  And  for  all  classes  the  color  is  a  not 
unimportant  gauge  of  purity.  So  that  the  general  applicable  analytical 
tests  for  petroleum  products  may  be  summed  up  under  the  following 
heads : 

Specific  gravity. 

Fire-test,  including  flash-point  and  burning  point. 

Cold-test. 

Viscosity. 

Melting  point. 

Compression-test. 

Colorimetric  tests. 

(a)  Specific  Gravity  Determinations. — While,  of  course,  the  methods 
of  the  specific  gravity  bottle  and  the  specific  gravity  balance  are  avail- 
able, the  determinations  are,  in  the  case  of  the  liquid  petroleum  products, 
almost  universally  made  with  hydrometers,  and  these  may  be  of  two 
kinds,  either  graduated  so  that  specific  gravities  are  read  off  direct  in 
decimal  fractions  less  than  one,  or  graduated  in  the  arbitrary  scales  of 
Beaume,  Brix,  Gay-Lussac,  or  Twaddle,  the  relations  of  which  to  simple 
fractional  specific  gravity  numbers  are  known.  In  America  and  Russia 
the  Beaume  scale  is  universally  adopted;  in  Germany,  the  Brix  spindle 
is  used  officially  by  customs  officers ;  in  France,  the  Gay-Lussac ;  and  in 
England,  the  Beaume  scale  for  liquids  lighter  than  water,  and  the 
Twaddle  for  liquids  heavier  than  water.  For  the  formulas  for  conver- 
sion of  readings  of  these  scales  into  specific  gravity  figures  and  for  a 
complete  table  of  Beaume  degrees  in  comparison  with  the  corresponding 
specific  gravity  figures,  see  Appendix.  The  use  of  vdirect  specific  gravity 
hydrometers  is  gradually  extending,  especially  in  Germany,  as  they  do 
away  with  the  necessity  of  all  reduction  tables.  The  specific  gravity 
tables  for  liquids  lighter  than  water  are  calculated  for  a  temperature  of 


ANALYTICAL  TESTS  AND  METHODS.  39 

60°  F.,  and  in  practice  it  is  customary  to  add  to  or  subtract  from  the 
observed  specific  gravities  .004  for  every  10°  F.  above  or  below  60°  F., 
and  this  is  found  to  afford  a  sufficiently  close  approximation  to  the  truth 
for  all  commercial  purposes  in  the  case  of  all  the  ordinary  petroleum 
products. 

(b)  Fire-test. — Just  as  crude  petroleum  is  dangerous  because  of  the 
dissolved  gases,  although  its  specific  gravity  may  be  relatively  high,  so 
illuminating  oils  may  give  off,  at  temperatures  far  below  their  boiling- 
point,  small  amounts  of  inflammable  vapors,  which  might  make  these  oils 
dangerous  for  use  in  lamps  where  the  oil  reservoir  gradually  becomes 
warm.  A  distillate  may  have  vapors  of  higher  and  lower  boiling-point 
carried  over  with  it.  Two  points  may  be  determined  with  a  petroleum 
oil,  the  flashing  point,  or  the  temperature  at  which  the  oil  gives  off 
vapors  which,  mixing  with  air,  cause  an  explosion  or  flash  of  flame, 
dying  out,  however,  at  once,  and  the  burning  point,  or  the  temperature 
at  which  a  spark  or  lighted  jet  will  ignite  the  liquid  itself,  which  then 
continues  to  burn.  The  latter  point  is  usually  6°  to  20°  C.  higher  than 
the  former,  but  there  is  no  fixed  relation  between  them.  The  danger, 
of  course,  begins  when  an  oil  will  flash,  so  the  flash-point  is  generally 
taken  as  the  basis  of  legal  prescription ;  Austria  and  the  New  York  Prod- 
uce Exchange  alone  recognize  formally  the  burning-test  instead  of  the 
flash-test.  Most  European  countries  and  most  of  the  States  in  the 
United  States  prescribe  a  flash-test.  The  United  States  have  no  national 
regulation  on  the  subject. 

The  different  forms  of  apparatus  in  use  to  determine  the  safety  of  oils 
are  based  upon  either  one  of  two  principles, — the  direct  determination 
of  flash  or  burning  point,  or  the  determination  of  the  increased  tension 
of  vapor  which  the  oil  shows  as  the  temperature  rises.  The  second  class 
is  represented  by  a  single  form  of  apparatus,  that  of  Salleron-Urbain, 
used  to  some  extent  in  France ;  the  first  class  is  represented  by  a  dozen 
or  more  different  forms,  chiefly  of  American,  English,  and  German  inven- 
tion. The  earliest  form,  that  of  the  Tagliabue  open-cup  tester,  is  shown 
in  Fig.  7,  in  which  the  glass  cup  Z>,  holding  the  oil  to  be  tested,  is 
heated  by  the  water-bath  A.  When  the  thermometer,  the  mercury  of 
which  is  just  immersed,  indicates  90°  F.  (32°  C.),  the  spirit  lamp  is 
withdrawn  and  the  temperature  allowed  to  rise  more  slowly  to  95°  F. 
(35°  C.),  when  a  lighted  splinter  of  wood  is  passed  to  and  fro  over 
the  surface  of  the  oil.  If  the  gas  rising  from  the  oil  does  not  ignite,  the 
water-bath  is  heated  again  and  tests  are  made  when  the  thermometer 
indicates  100°  F.  (38°  C.),  104°  F.  (40°  C.),  and  108°  F.  (42°  C.).  A 
flash  at  108°  F.  is  considered  as  marking  the  oil  at  110°  F.  This  form 
was  the  first  one  officially  adopted  in  the  United  States,  and  is  still  used 
somewhat  in  Germany  and  Austria.  The  New  York  Produce  Exchange 
and  the -American  petroleum  inspectors  have  now  adopted  an  open-cup 
tester,  known  as  the  Saybolt  tester,  in  which  the  electric  induction-spark 
is  made  to  pass  over  the  top  of  the  open  oil-cup.  It  is  shown  in  Fig.  8. 
F  is  a  water-bath,  the  temperature  of  which  is  noted  by  an  independent 
thermometer.  Although  this  was  a  decided  improvement  on  the  first 


40        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 

Tagliabue  apparatus,  it  was  found  that,  like  the  other  open-cup  appa- 
ratus, it  gave  readings  which  were  variable  and  higher  than  if  the  top 
of  the  cup  were  covered.  This  led  to  the  study  of  the  whole  subject  by 
Sir  Frederick  Abel,  at  the  request  of  the  English  government,  and  the 
adoption  by  the  English  government  as  their  official  standard  of  the 

FIG.  7. 


Abel  tester.  This  has  since  been  adopted  by  the  German  government  as 
well,  and  is  considered  by  many  to  be  the  most  exact  now  in  use.  It  is 
shown  in  Fig.  9.  The  following  is  a  description  of  the  details  of  the 
apparatus:  "The  oil-cup  consists  of  a  cylindrical  vessel,  two  inches  in 
diameter,  two  and  two-tenths  inches  high  (internal),  with  outward 
projecting  rim  five-tenths  inch  wide,  three-eighths  inch  from  the  top, 
and  one  and  seven-eighths  inches  from  the  bottom  of  the  cup.  It  is 
made  of  gun-metal  or  brass  (17  B.  "W.  G.),  tinned  inside.  A  bracket, 


ANALYTICAL  TESTS  AND  METHODS. 


41 


consisting  of  a  short,  stout  piece  of  wire,  bent  upward,  and  terminating 
in  a  point,  is  fixed  to  the  inside  of  the  cup  to  serve  as  a  gauge.  The  dis- 
tance of  the  point  from  the  bottom  of  the  cup  is  one  and  a  half  inches. 
The  cup  is  provided  with  a  close-fitting,  overlapping  cover,  made  of 
brass  (22  B.  W.  G.),  which  carries  the  thermometer  and  test-lamp.  The 
latter  is  suspended  from  two  supports  from  the  side  by  means  of  trun- 
nions, upon  which  it  may  be  made  to  oscillate;  it  is  provided  with  a 

FIG.  9. 


Fia.  10. 


spout,  the  mouth  of  which  is  one-sixteenth  of  an  inch  in  diameter.  The 
socket  which  is  to  hold  the  thermometer  is  fixed  at  such  angle,  and  its 
length  is  so  adjusted,  that  the  bulb  of  the  thermometer,  when  inserted 
to  full  depth,  shall  be  one  and  a  half  inches  below  the  centre  of  the  lid. 
The  cover  is  provided  with  three  square  holes,  one  in  the  centre,  five- 
tenths  inch  by  four-tenths  inch,  and  two  smaller  ones,  three-tenths  inch 
by  two-tenths  inch,  close  to  the  sides  and  opposite  each  other.  These 
three  holes  may  be  closed  and  uncovered  by  means  of  a  slide  moving  in 
grooves  and  having  perforations  corresponding  to  those  on  the  lid.  In 
moving  the  slide  so  as  to  uncover  the  holes,  the  oscillating  lamp  is  caught 
by  a  pin  fixed  in  the  slide  and  tilted  in  such  a  way  as  to  bring  the  end 


42        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 

of  the  spout  just  below  the  surface  of  the  lid.  Upon  the  slide  being 
pushed  back  so  as  to  cover  the  holes,  the  lamp  returns  to  its  original 
position."  Not  only  are  all  the  dimensions  of  parts  in  the  Abel  appa- 
ratus prescribed  most  minutely,  but  the  method  of  carrying  out  the  test 
must  be  followed  in  minute  particulars  in  order  to  get  accurate  results. 
The  opening  and  closing  of  the  slide  must  be  regulated  either  by  a 
seconds  pendulum  or,  as  in  the  official  German  apparatus,  by  exact  clock- 
work. It  gives  a  flash-test  which,  on  the  average,  is  27°  F.  lower  than 
that  of  the  open-cup  apparatus,  so  that  73°  P.  Abel  test  is  taken  as  the 
equivalent  of  100°  F.  open-cup  test. 

A  German  apparatus,  which  seems  to  be  fully  as^exact,  and  simpler 
in  its  construction  and  operation,  is  Heumann's  tester,  shown  in  Fig.  10. 
In  it  the  results  are  to  a  considerable  degree  independent  of  the  dimen- 
sions of  the  oil-cup,  size  of  flame,  temperature  of  water,  etc.  This  appa- 
ratus shows  to  what  temperature  a  specimen  of  petroleum  must  bo 
heated  through  and  through  in  order  that  the  vapor  given  off  may  suffice 
to  make  an  explosive  mixture  with  a  volume  of  air  exactly  equal  to  the 
volume  of  oil.  The  glass  oil-vessel,  g,  is  set  direct  in  the  metallic  water- 
bath,  &,  and  is  exactly  half-filled  with  oil  with  the  aid  of  a  measure 
accompanying  the  instrument.  The  agitating  paddles,  c,  agitate  the  oil 
and  the  air-and-vapor  mixture  independently.  The  little  flame  or  lamp 
for  igniting  the  explosive  mixture  is  attached  to  a  button  at  d,  and  here 
is  a  small  hole  through  which  the  gas-and-air  mixture  escapes,  and,  when 
ignited,  yields  a  flame  about  five  millimetres  high.  In  making  the  test, 
after  agitation  of  the  mixture,  the  button,  k,  is  pressed  down  until  the 
little  flame  is  pushed  below  the  surface,  when,  if  the  temperature  of 
flashing  has  been  reached,  it  ignites  the  explosive  mixture  of  air  and 
vapor,  and  is  blown  out  in  turn  by  the  slight  puff  of  the  explosion.  The 
apparatus  is  said  to  give  results  agreeing  perfectly  with  those  gotten 
with  the  more  complicated  but  official  Abel  tester.  Other  forms  of  appa- 
ratus are  those  of  Engler  (a  closed  test  apparatus  with  the  Saybolt 
electric  spark  attachment),  of  Parrish,  used  in  Ilolland,  and  of  Bernstein. 

Victor  Meyer  first  adopted  the  principle  that  the  true  flash-point  of 
a  petroleum  is  that  temperature  at  which  air,  shaken  with  petroleum, 
can  be  ignited  by  a  small  flame,  and  proposed  the  thorough  agitation  of 
the  warmed  oil  to  be  tested  with  air  before  applying  the  flame.  The 
simplest  form  of  apparatus  in  which  this  principle  is  applied  is  the 
flash-tester  of  Stoddard,  shown  in  Fig.  11.  The  air-current  escapes  from 
a  fine-drawn  opening  in  the  glass  tube,  and  must  raise  a  foam  several 
millimetres  in  height  on  the  surface  of  the  oil.  The  cylinder  containing 
the  oil  may  be  a  small  Argand  lamp-chimney,  and  the  whole  apparatus 
is  lowered  into  a  water-bath.  The  little  jet  of  flame  is  passed  to  and 
fro  over  the  opening  at  the  top  of  the  chimney,  while  the  thermometer, 
immersed  in  the  oil,  is  read. 

For  lubricating  oils  where  the  flash-point  is  to  be  determined  with 
accuracy,  the  Pensky-Martens  testing  apparatus,  which  is  a  modifica- 
tion of  the  Abel  tester,  is  used.  Mechanical  agitation  is  provided,  and 
the  oil-cup  is  surrounded  with  an  air-bath.  In  the  United  States  the 


ANALYTICAL  TESTS  AND  METHODS. 


43 


flash,  test  of  lubricating  oils  is  generally  taken  in  a  shallow  open  cup 
heated  directly,  the  temperature  being  raised  at  the  rate  of  8°  F.  per 
minute. 

(c)  Cold  Test. — This  is  applied  chiefly  to  lubricating  oils.  The  exe- 
cution of  it  with  Tagliabue's  standard  oil-freezer  is  shown  in  Fig.  12. 
The  glass  oil-cup,  four  inches  in  depth  and  three  inches  in  diameter, 
is  adjusted  to  a  rocking  shaft,  seen  at  the  side  of  the  cup,  so  as  to  show 
by  its  motion  whether  the  oil  is  congealing  or  not.  Surrounding  the  oil- 
cooling  chamber  is  the  ice-chamber,  and  outside  of  this  is  a  non-con- 

FIG.  12. 


ducting  jacket  filled  with  mineral  wool.  Three  thermometers  are  used: 
one  in  the  oil-cup  and  the  other  two  in  the  ice-chamber  to  either  side. 
Two  stopcocks  below,  communicating  with  the  cooling-chamber,  allow 
of  the  forcing  in  of  warm  atmospheric  air  to  raise  the  temperature 
within  when  necessary.  A  glass  door  in  the  side  opposite  the  oil-cup 
allows  of  the  reading  of  the  thermometer  without  opening  the  cooling- 
chamber.  The  cold-test  is  also  frequently  applied  by  simply  taking  the 
oil  in  a  sample  bottle,  the  diameter  of  which  is  about  one  and  a  half 
inches,  chilling  it  in  a  freezing  mixture,  and  noting  the  temperature  at 
which,  on  inclining  the  tube,  the  oil  no  longer  flows,  or  that  at  which 
the  separation  of  paraffin  commences. 

(d)  Viscosity  Test. — As  before  stated,  the  "viscosity  "  or  body  of  a 
lubricating  oil  is  one  of  its  most  important  characters.  Its  determina- 
tion is,  therefore,  to  be  made  with  great  care.  The  earlier  forms  of 
apparatus  consisted  simply  of  glass  tubes,  of  pipette  form,  which,  being 


44        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 


filled  with  oil  to  a  certain  mark,  were  allowed  to  empty  while  the  time 
was  accurately  noted.  The  pipette  was  set  in  a  hot-water  funnel  or 
similar  vessel,  and  the  water  in  this  outer  vessel  brought  to  60°  F.,  so 
that  the  observation  on  the  oil  might  be  at  a  standard  temperature. 

Other  forms  are  those  of  Coleman,  Mason,  and  Redwood,  in  England, 
and  F.  Fischer  and  C.  Engler,  in  Germany.  The  Redwood  viscosimeter, 
a  very  accurate  instrument,  will  be  found  described  and  illustrated  fully 
in  "Allen's  Commercial  Organic  Analysis"  (2d  ed.,  vol.  ii.  p.  198). 
The  Fischer  viseosimeter  is  shown  in  Fig.  13.  The  outer  vessel,  B, 

FIG.  14. 


FIG.  13. 


having  been  filled  with  warm  water,  the  oil-vessel,  A,  has  placed  in  it 
about  sixty-five  cubic  centimetres  of  the  oil  sample,  filling  it  to  a 
mark  on  the  inside.  "When  the  thermometer,  immersed  in  the  oil,  shows 
the  proper  temperature,  fifty  cubic  centimetres  are  allowed  to  run  into 
a  graduated  flask  placed  below  and  the  time  required  for  its  flow  noted. 
The  exit-tube,  a,  consists  of  a  platinum  tube  1.2  millimetres  wide  and 
5  millimetres  long,  which  is  surrounded  by  a  wider  copper  tube.  This 
exit-tube  is  enlarged  conically  at  either  end,  above  to  allow  of  the 
closing  by  the  conical  plug,  &,  and  below  to  allow  of  the  better  flow  of 
the  escaping  oil.  In  the  Engler  instrument,  illustrated  in  Fig.  14,  still 
greater  care  is  taken  to  insure  accurate  measurement  of  the  volume  of 
oil  operated  upon,  and  that  it  shall  flow  under  exactly  similar  conditions 
in  comparative  tests.  Two  hundred  and  forty  cubic  centimetres  of 
water  fill  the  inner  vessel  just  to  the  mark  c,  and  when  the  temperature 


ANALYTICAL  TESTS  AND  METHODS. 


Fia.  15. 


of  20°  C.  (68°  F.)  is  reached,  two  hundred  cubic  centimetres  are  run 
out  into  the  vessel  below.  The  oil  to  be  tested  is  similarly  filled  in  to 
the  mark,  and  when  the  temperature  20°  C.  is  reached,  after  keeping  the 
oil  at  this  for  some  three  minutes,  the  plug,  &,  is  withdrawn,  and  two 
hundred  cubic  centimetres  are  run  into  the  vessel  below,  while  the  time 
required  is  accurately  noted.  This  time  in  seconds,  divided  by  the  time 
in  seconds  required  for  the  running  of  the  same  volume  of  water,  gives 
the  specific  viscosity  or  viscosity-grade,  as  Engler  terms  it. 

The  lubricating  value  of  oils  can  be  determined  best  by  actual  use 
upon  the  surfaces  where  friction  is  felt,  and  instruments  to  determine 
such  value  are,  therefore,  based  upon  experimental  trials  of  the  diminu- 
tion of  friction  on  moving  surfaces,  when  covered  by  the  oils  to  be  com- 
pared. Such  an  instrument  is  the  well- 
known  Thurston  lubricating  oil-tester, 
shown  in  Fig.  15,  in  which  both  the  re- 
sistance in  the  speed  of  revolution  of  a 
rotating  axis  due  to  friction  and  the  heat- 
ing of  the  axis  and  the  bearing  in  which 
it  rotates  are  measured. 

Mineral  lubricating  oils  are  frequently 
adulterated  with  seed  oils  like  "blown 
rape  oil  "  or  blown  cottonseed,  both  being 
added  to  give  increased  viscosity.  Arti- 
ficial viscosity  is  also  given  to  less  viscous 
mineral  lubricating  oils  by  the  addition  of 
aluminum  oleate  or  palmitate.  These 
fixed  oils  may  be  detected  by  saponifying 
with  alcoholic  potash  (see  p.  88).  For 
the  detection  of  rosin  oil  adulteration  Allen 
recommends  the  addition  to  a  few  drops  of 
the  sample  dissolved  in  about  one  cubic  centimetre  of  carbon  disulphide 
of  a  solution  of  stannic  bromide  with  excess  of  bromine  in  carbon  disul- 
phide. (The  stannic  bromide  is  prepared  by  allowing  bromine  to  fall 
drop  by  drop  upon  granulated  -  tin  contained  in  a  flask  immersed  in 
cold  water.)  The  production  of  a  fine  violet  color  indicates  the  presence 
of  rosin  oil.  Gumming  tests  for  lubricating  oils  are  now  considered 
important,  as  oils  containing  much  dissolved  pitchy  or  asphaltic  matter 
resinify  rapidly  at  50°  C.  to  100°  C.,  while  pure  hydrocarbon  lubricating 
oil  slowly  evaporates  without  resinification. 

Determination  of  Asphaltic  Residue  in  Lubricating  Oils. — Holde 
gives  the  following  method.  Five  grams  of  the  oil  are  dissolved  at  15° 
C.  in  25  volumes  of  ether;  to  this  solution  is  added  from  a  burette  drop 
by  drop  with  constant  shaking  of  the  mixture  12.5  volumes  of  alcohol 
of  ninety-six  per  cent,  strength.  After  allowing  the  mixture  to  stand  for 
five  hours  at  15°,  it  is  filtered  through  a  folded  filter,  washed  with  a 
mixture  of  alcohol-ether  (1:2)  until  no  further  oily  substances  but 
traces  only  of  pitchy  constituents  go  through  into  the  filtrate.  The  washed 
asphaltic  residue,  which  can  also  contain  paraffin,  is  dissolved  in  benzol, 


46        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 

the  solution  evaporated  to  dryness,  and  the  residue  extracted  by  thirty 
cubic  centimetres  of  ninety-six  per  cent,  alcohol  at  boiling  temperature, 
repeated  again  until  the  extraction  liquor  on  cooling  shows  no  further 
precipitation  of  paraffin.  The  residue  is  then  dried  for  a  quarter  of  an 
hour  at  105°  C.  and  weighed  when  cold. 

(e)  Melting  Point. — The  "melting  point  "  of  paraffin  should  rather 
be  called  the  congealing  point,  as  what  is  taken  usually  is  the  tempera- 
ture at  which  the  sample,  after  having  been  melted,  and  while  in  the 
process  of  cooling,  begins  to  solidify.  The  American  test  is  con- 
ducted by  melting  sufficient  of  the  samples  to  three-fourths  fill  a  hemi- 
spherical dish  three  and  three-fourths  inches  in  diameter.  A  thermom- 
eter with  a  round  bulb  is  suspended  in  the  fluid  so  that  the  bulb  is  only 
three-fourths  immersed,  and  the  material  being  allowed  to  cool  slowly, 
the  temperature  is  noted  at  which  the  first  indication  of  filming,  extend- 
ing from  the  sides  of  the  vessel  to  the  thermometer  bulb,  occurs.  The 
English  test  is  made  by  melting  the  sample  in  a  test-tube  about  three- 
quarters  of  an  inch  in  diameter,  and  stirring  it  with  a  thermometer  as  it 
cools,  until  a  temperature  is  reached  at  which  the  crystallization  of  the 
material  produces  enough  heat  to  arrest  the  cooling,  and  the  mercury 
remains  stationary  for  a  short  time.  The  results  afforded  by  this  test 
are  usually  from  2y2°  to  3°  P.  lower  than  those  furnished  by  the  Ameri- 
can test.  The  melting  point  is  also  sometimes  determined  by  observing 
the  temperature  at  which  a  minute  quantity  of  the  sample  previously 
fused  into  a  capillary  tube,  and  allowed  to  set,  becomes  transparent  when 
the  tube  is  slowly  warmed  in  a  beaker  of  wrater. 

(/)  Compression  Test. — Paraffin  scale  usually  contains  oil  and  some- 
times water.  The  percentage  of  oil  is  determined  by  subjecting  a  weighed 
quantity  of  the  material  to  a  given  pressure  for  a  specified  time  and 
noting  the  loss  in  weight.  The  test  is  made  at  60°  F.,  the  quantity  of 
material  employed  five  hundred  grains,  the  pressure  is  nine  tons  over 
the  whole  surface  of  the  circular  press-cake,  five  and  five-eighths  inches 
in  diameter,  and  this  pressure  is  maintained  for  five  minutes,  the  oil 
expressed  being  absorbed  by  blotting-paper. 

(g)  Colorimetric  Test. — The  color  of  petroleum  oil  is  determined  in 
the  United  States  (as  regards  oil  for  export),  in  England,  and  in  Russia 
(in  the  case  of  oil  for  export)  mainly  by  the  use  of  the  Wilson  chro- 
mometer.  In  Germany  they  use  both  a  modification  under  the  name 
of  the  Wilson-Ludolph  chromometer  and  Stammer's  colorimeter.  The 
Wilson  instrument,  shown  in  Fig.  16  and  Fig.  17,  is  fitted  with  two 
parallel  tubes,  furnished  with  glass  caps,  and  at  the  lower  end  of  the 
tubes  is  a  small  mirror  by  means  of  which  light  can  be  reflected  upward 
through  the  tubes  with  an  eye-piece.  One  of  these  tubes  is  completely 
filled  with  the  oil  to  be  tested,  and  beneath  the  other  tube,  which  remains 
empty,  is  placed  a  disk  of  stained  glass  of  standard  color.  On  adjusting 
the  mirror  and  looking  into  the  eye-piece  the  circular  field  is  seen  to  be 
divided  down  the  centre,  each  half  being  colored  to  an  extent  correspond- 
ing with  the  tint  of  the  oil  and  of  the  glass  standard  respectively.  An 
accurate  comparison  of  the  two  colors  can  thus  be  made.  The  glass 


ANALYTICAL  TESTS  AND  METHODS. 


47 


disks,  which  for  the  English  trade  are  of  five  shades  of  color,  termed 
good  merchantable,  standard  white,  prime  white,  superfine  white,  and 
water  white,  are  issued  by  the  Petroleum  Association  of  London.  In 
Germany,  the  Bremen  Exchange  recognizes  seven  shades  of  color, — 
straw,  light  straw,  prime  light  straw  to  standard  white,  prime  light 
straw  to  white,  standard  white,  prime  white,  and  water  white. 

In  addition  to  these  special  tests  there  may  be  mentioned  a  general 
method  recently  devised  by  A.  Riche  and  G.  Halphen  (Journ.  Pliarm. 
Chem.,  1894,  xxx.  289)  for  determining  whether  a  petroleum  distillate 
has  been  obtained  from  American  or  Russian  crude  petroleum,  and  for 
distinguishing  crude  petroleum  from  mixtures  of  petroleum  distillate 
and  residuum.  The  process  consists  in  the  gradual  addition  by  means 


FIG.  16. 


FIG.  17. 


of  a  burette  of  a  mixture  of  equal  volumes  of  anhydrous  chloroform  and 
ninety-three  per  cent,  alcohol  to  four  grammes  of  the  sample  of  the  oil 
until  solution  is  effected  and  the  liquid  becomes  clear.  It  was  fd  u 
that  samples  of  crude  petroleum  required  much  more  of  the  solvent  to 
produce  a  clear  liquid  than  fractions  of  the  same  density  obtained  by 
distillation,  and  that  the  higher  boiling  fractions  of  American  petro- 
leum required  a  larger  quantity  of  the  solvent  than  sufficed  for  the 
Russian  product  of  corresponding  specific  gravity. 

4.  FOR  OZOKERITE. — The  physical  tests  are  the  same  as  those  for 
paraffin  scale. 

5.  FOR  ASPHALTS. — When  asphalts  and  bitumens  are  to  be  used  for 
varnish-making,  the  determination  of  the  total  bitumen  soluble  in  carbon 
disulphide  or  oil  of  turpentine  suffices.    When,  on  the  other  hand,  the 
asphalt  is  to  be  considered  with  reference  to  its  value  for  asphalt  paving 
purposes,  it  is  necessary  to  examine  into  the  quality  of  the  bitumen. 
For  this  purpose  the  total  bitumen    (amount  soluble  in  carbon  disul- 
phide), organic  non-bitumen,  and  ash  are  first  determined.     Then  the 
amount  of  bitumen  soluble  in  petroleum-naphtha  (so  called  petrolene) 


48       PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 

is  ascertained.  The  difference  between  this  and  the  total  bitumen  is 
called  asphaltene.  The  former  of  these  portions  is  in  general  tough  and 
elastic,  while  the  latter  is  hard  and  brittle.  For  paving  purposes  the 
asphalt  should  contain  an  excess  of  petrolene  over  asphaltene. 

Clifford  Richardson  considers  it  desirable  to  extract 'with  naphthas 
of  62°  B.  and  88°  B.  separately,  in  order  to  get  a  correct  estimate  of 
the  quality  of  the  "petrolene."  Chloroform  is  also  used  at  times  in 
place  of  carbon  disulphide. 

The  liquid  asphalts  or  malthas  sometimes  contain  so  much  material 
volatile  at  temperatures  below  300°  F.  that  the  simple  determination  of 
bitumen  soluble  in  petroleum-naphtha  would  be  misleading  and  valueless 
unless  they  were  previously  heated  to  drive  off  these  light  oils,  as  these 
volatile  portions  are  not  comparable  in  value  with  the  petrolene  of  solid 
asphalts.  Therefore  a  test  is  commonly  made  of  the  percentage  of  loss 
in  such  asphalts  when  heated  to  300°  F.  or  400°  F.  for  ten  hours,  and 
this  is  then  taken  in  connection  with  the  extraction  tests. 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

The  following  list  of  titles  i3  not  meant  to  be  complete,  but  only  gives  the  more 
important  published  works  of  recent  years.     It  does  not  cover  periodical  literature, 
which  is  very  voluminous: 
1876-86. — Reports  of  the  Second  Geological  Survey  of  Pennsylvania  on  Oil  Regions, 

Harrisburg,  Pa. 

1877. — Geological  Survey  of  the  Oil  Lands  of  Japan,  B.  S.  Lyman,  Tokio. 
1879. — Untersuchungen  tiber  naturliche  Asphalte,  R.  Kayser,  Nuremberg. 
1884. — Petroleum  Distillation,  A.  N.  Leet,  New  York. 

Naphtha  and  Naphtha  Industrie,  V.  Ragosine,  St.  Petersburg. 

The  Region  of  Eternal  Fire,  Chas.  Marvin,  London. 

Photogen  und  Schmierol  aus  Baku'scher  Naphta,  F.  RossmJissler,  Halle. 
1885. — Lecons  sur  le  P&trole  et  ses  D6riv6s,  Chas.  Augenot,  Antwerp. 

Census  Report  of  1880  on  Petroleum  and  its  Products,  S.  F.  Peckham,  Wash- 
ington. 

Destructive  Distillation,  Ed.  J.  Mills,  third  edition,  London. 
1886. — Verarbeitung  des  Naphta  oder  des  Erdols,  F.  Rossmassler,  Halle. 
1886-88.— Mineral  Resources  of  the  United  States  for  1886-88  (Petroleum,  by  J.  D. 

Weeks ) ,  Washington. 
1887. — Das  Erdol  von  Baku,  C.  Engler,  Stuttgart. 

Cantor  Lectures  on  Petroleum  and  its  Products,  B.  Redwood,  London. 

Practical  Treatise  on  Petroleum,  B.  Crew,  Philadelphia. 

Ueber  das  Deutsche  Rohpetroleum,  Kramer  und  Bottcher,  Berlin. 

Das  Deutsche  Erdol,  C.  Engler,  Berlin. 

Preliminary  Report  on  Petroleum  and  Inflammable  Gas,  E.  Orton,  Columbus, 
Ohio. 

Fette  und  Oele  der  Fossilien   (Mineral  Oele),  G.  Schaedler,  Leipzig. 

Die  Deutsche  Erdole,  C.  Engler,  Stuttgart. 

Schmierol  Untersuchungen,  A.  Martens,  Berlin. 

L'Asphalte,  son  origine,  sa  preparation,  etc.,  Leon  Malo,  Paris. 
1889. — L'Industrie  du  Petrole,  Ph.  Delahaye,  Paris. 
1890. — Aux  Pays  du  Pfitrole — Histoire,  Origines,  etc.,  F.  riue,  Paris. 
1892. — Das  Erdol  und  seine  Verarbeitung,  A.  Veith,  Braunschweig. 

Production,   Industrie  et   Commerce  des   Huiles  Min6rales   aux  Etats-Unis, 
Riche,  Paris. 


BIBLIOGRAPHY  AND  STATISTICS. 


49 


1893. — Die  Petroleum  und  Schmierolfabrikation,  F.  A.  Rossmassler,  Leipzig. 
Vegetabilische  und  Mineral-Maschinenole,  L.  Andes,  Wien. 
Twenty  Years'  Experience  of  Natural  Asphalt,  W.  H.  Delano,  London. 
1894. — Die  Schmiermittel,  J.  Grossman,   Wiesbaden. 

Technologic  der  Landwirthschaftlichen  Gewerbe  und  Abhandlung  iiber  Mineral 

Oele,  Dr.  B.  von  Posauner,  4te  Auf.,  Wien. 

Gas-  and  Petroleum-yielding  Formations  of  California,  W.  L.  Watts,  Sacra- 
mento, California. 
1895. — Petroleum  and  Natural  Gas,  Wm.  T.  Brannt,  Philadelphia. 

Groves  and  Thorp's  Chemical  Technology,  vol.  ii.,  The  Petroleum  Industry 

and  Lamps,  Boverton  Redwood,  Philadelphia. 
Die  Fabrikation  der  Mineral  Oele,  W.  Schiethauer,  Braunschweig. 
1896. — Le  Petrole,  Riche  et  Halphen,  Paris. 

Lubricating  Oils,  Fats,  and  Greases,  Geo.  H.  Hurst,  London. 
1897. — Oil-    and    Gas-yielding    Formations    of    Los    Angeles,    Ventura,    and    Santa 

Barbara  Counties,  Sacramento,  California. 
Mineral  Oils  and  their  By-products,  I.  I.  Redwood,  London. 
1898. — Ueber  Hannoverisch  Erdoelvorkomnisse,  Dr.  Otto  Lang,  Hannover. 

On  the  Nature  and  Origin  of  Asphalt,  Clifford  Richardson,  New  York. 
A  Short  Hand-Book  of  Oil  Analysis,  A.  H.  Gill,  Philadelphia. 
1899. — Der  Asphalt  und  seine  Anwendung,  W.  Jeep,  Leipzig. 
1904. — Die  Chemie  und  Technologic  der  Natiirlichen  und  Kunstlichen  Asphalte,  von 

Hippolyt  Kohler,  Braunschweig. 
1906. — Die    Untersuchung   des    Erdoels    und    seine    Producte,    von   M.    A.    Rakusin, 

Braunschweig. 

Des  Erdoel  und  seine  Verwandten,  Hans  Hb'fer,  2nd  Auf.,  Braunschweig. 
Petroleum  and  its  Products,  by  Sir  B.  Redwood,  2nd  Edition,  2  vols.     London. 
Die  Asphalt  Industrie,  von  Felix  Lindenberg-Hartleben,  Wien. 

1907. — Lubrication  and  Lubricants,  A  Treatise  on  Theory  and  Practice,  etc.,  L.  Arch- 
butt  and  R.  M.  Deeley,  London. 

1908. — Modern  Asphalt  Pavement,  Clifford  Richardson,  2nd  Edition,  New  York. 
Das  Erdoel,  seine  vevarbeitung,  etc.,  R.  Kissling,  Halle. 
Exploitation  du  Petrole,  Historique,  etc.,  L.  C.  Tassart,  Paris. 
Erdwachs,  Paraffin,  und  Montanwachs,  R.  Gregorius,  Wien. 
1909.— Das  Erdoel,  von  C.  Engler  und  H.  Hoefer,  3  Bande,  Leipzig. 

Untersuchung  der  Mineraloele   und   Fette,   Dr.   D.   Holde,   3te   Auf.,   Julius 

Springer,  Berlin. 
Solid  Bitumens,  Physical  and  Chemical  Properties,  S.  F.  Peckham,  Myron 

C.  Clark  Pub.  Co.,  New  York. 

1910. — Allen's  Commercial  Organic  Analysis,  4th  Edition,  vol.  iii,  Philadelphia. 
1911.— Oil  Analysis,  Augustus  H.  Gill,  6th  Ed.,  Philadelphia. 

STATISTICS. 

1.  FOR  NATURAL  GAS. — The  production  of  natural  gas  is  not  officially 
reported  in  quantities,  but  in  value  based  on  the  coal  displaced  as  fuel. 
Approximate  Value  of  Natural  Gas  produced  in  the  United  States,  1904-09. 


LOCALITIES. 

1904. 

1907. 

1908. 

1909. 

Pennsylvania  . 

$18,139  914 

$18  55*<  245 

$19  104  944 

$20  475  207 

Ohio  

5,315,564 

7,145  809 

8  244  835 

9  ggg  938 

Indiana   

4  342  409 

1  750  715 

1  312  507 

1  616  903 

West  Virginia  

8,114/249 

13  735  343 

14  837  130 

17  538  565 

Kansas    

1,517,643 

4,010,986 

7  691  587 

8  293  846 

Other  States  

1,066,981 

1,672,834 

3,616,303 

5,485,482 

Total  

$38  496,760 

$46  873  932 

$54  807  306 

$63  376  941 

614. 


Canada,  also,  in  1910  produced  natural  gas  to  the  value  of  $1,312,- 


50   PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 


2.  FOR  PETROLEUM. — The  most  important  petroleum-producing  coun- 
tries for  the  years  1907-1910  furnished  the  following  amounts  of  petro- 
leum, expressed  in  metric  tons  and  percentage  proportion : 


1907. 

1908. 

1909. 

1910. 

United  States  .  .  .  . 
Russia  

Per  cent. 
22,149,862—63.1-2 
8,247,795—23.50 

Per  cent. 
24,401,728—62.97 
7,654  600—19.75 

Per  cent. 
24,433,528—62.33 
8,037  300—20.50 

Per  cent. 

29.585,973—64.68 
8.952  793—19.57 

Dutch  Indies  .... 
Galicia  

1,178,797—  3.36 
1,175,974  —  3  36 

2,348,000—  6.06 
1  754  002  —  4  53 

1,497,275—  3.82 
2  150  000  —  5  49 

2.024,000—  4.42 
1  491  600  —  3  26 

Roumania  

1,129  097—  3  22 

1  147  727  —  2  96 

1  263  946—  3.22 

1  352  300—  2  95 

British  Indies  .... 
Other  countries  .  .  . 

579,316—  1.65 
633,245—  0.79 

568,000—  1.46 
880,000—  2.27 

905,336—  2.31 
910,000—  2.33 

1,017,000—  2.22 
1,328,880—  2.90 

35,094,086  100.00 

38,754,057  100.00 

39,197,385  100.00 

45,752,546  100.00 

The  production  of  the  United  States  for  the  years  1906  to  1910  was 
distributed  as  follows  (in  barrels  of  42  gallons)  : 


1906. 

1907. 

1908. 

1909. 

1910. 

California  

30,538  000 

39  748  375 

44,854,737 

54,433,010 

77,707,546 

Colorado    >      .... 

400000 

331  851 

,-,   lf  (Texas 

13,000,000  ) 

Qulf{  Louisiana    .  .  .  .  .  .  .  .  .  .  . 

7,000,000  j 

17,322,917 

17,318,330 

11,912,058 

»  i       f  Indiana                                    .  1 

Lima{onio    .....:::::} 

25,680,000 

17,335,485 

10,032,305 

6,600,000 

Illinois     

24,281,973 

33,685,106 

30,898,339 

33,000,000 

Mid-Continental  {ggg^  '.•'.*', 
Kentucky  and  Tennessee 

21,924,905 
1,200,000 

45,933,649 
820,844 

48,323,810 

(Pennsylvania  .  .  .  .  ) 
Appalachians  New  York           .  .  .  > 

27,345,600 

20,356,902 

24,945,517 

26,535,844 

26,550,000 

(  West  Virginia  .  .  .  .  j 
Wyoming 

8,000 

9339 

Other  States    

3,000 

4,000 

412,6-4 

338,658 

350,000 

127,099,505 

166,095,335 

179,572,479 

182,134,274 

213,531,117 

(The  Mineral  Industry  for  1910  and  U.  S.  Geol.  Survey,  1907.) 

The  exportation  of  crude  oil  and  the  various  products  therefrom  for 
the  years  1903-1907  is  shown  in  the  annexed  table : 


Year 
ending 
June  30th. 

Mineral  crude  (  all  gravi- 
ties). 

Naphthas,  benzine, 
gasolene,  etc. 

Illuminating  oils. 

Gallons. 

Dollars. 

Gallons. 

Dollars. 

Gallons. 

Dollars. 

1903  .    . 
1904  .    . 
1905  .    . 
1906  .    . 
1907  .    . 

134,892,170 
114,576,920 
123,059,010 
139,688,615 
128,175,737 

6,329,899 
6,572,923 
6,359,435 
7,016,131 
6,626,896 

13,139,228 
16,910,121 
30,816,655 
32,756,694 
26,357,054 

1,225,661 
1,802,207 

2,575,851 
2,613,677 
2,735,598 

699,807,201 
741,567,086 
882,881,953 
864,361,210 
894,529,432 

47,078,971 
57,902,503 
56,169,606 
54,181,617 
56,249,991 

Year 
ending 
June  30th. 

Lubricating  and  heavy 
paraffin  oils,  etc. 

Residuum  and  tar, 
pitch,  etc. 

Total. 

Gallons. 

Dollars. 

Gallons. 

Dollars. 

Gallons. 

Dollars. 

1903  .    . 
1904  .    . 
1905  .    . 
1906  .   . 
1907  .    . 

93,318,257 
88,810,130 
97,357,196 
146,110,702 
136,140,226 

12,052,927 
12,048,842 
13,142,860 
17,974,721 
17,179,562 

22,801,506 
22,560,510 
48,949,362 
75,031,824 
65,228,009 

566,115 
733,994 
1,545,470 
2,255,181 
2,063,668 

963,958,362 
984,424,767 
1,123,064,176 
1,257,949,042 
1,250,430,458 

67,253,573 
79,060,469 
79,793,222 
84,041,327 

84,855,715 

(Commerce  and  Navigation  of  U.  S.,  1907.) 


BIBLIOGRAPHY  AND  STATISTICS. 


51 


The  exportations  of  paraffin  and  paraffin  wax  for  the  same  years, 
1903-1907,  according  to  the  same  authority,  were  as  follows: 

For  1903  201,325,210  pounds,  valued  at  $9,411,294 

"  1904  .  188,651,119    "       "     8,859,964 

"  1905  161,894,918    "       "     7,789,160 

"  1906  178,385,368    "       "     8,808,245 

"  1907  185,511,773    "      "    9,030,992 

Next  in  importance  to  the  production  of  the  United  States  is  that  of 
Russia.  This  has  declined  in  recent  years  because  of  disturbing  causes, 
but  is  slowly  increasing  again.  The  figures  for  1903-1907  as  quoted 
from  the  U.  S.  Geological  Survey  Reports  are : 

Baku.       Grozny.        Total. 

1903  in  barrels 71,618,386    3,972,870    75,591,256 

1904  "  "  73,723,290  4,813,365  78,536,655 

1905  "  "  49,791,356  5,168,914  54,960,270 

1906  "  "  53,723,889  4,606,675  58,897,311 

1907  "  "  57,143,097  4,707,637  61,850,734 


The  petroleum  consumption  of  different  countries  in  kilos,  for  the 
year  1904,  reckoned  on  a  per  capita  basis,  has  been  stated  as  follows : 


Population. 

United  States  of  America 80,000,000 

Germany    58,000,000 

England 44,000,000 

France 38,000,000 

Russia    140,000,000 

Japan   45,000,000 

Roumania    6,000,000 

Austria-Hungary   50,000,000 

India    300,000,000 

China   300,000,000 


Per  capita 

Consumption  in  1904. 

consumption 

20,166,803  metric  centners 

25.21 

kilos. 

7,990,601       " 

13.78 

M 

5,209,330 

11.84 

M 

3,122,097       " 

8.22 

M 

10,507,887       " 

7.51 

M 

2,993,700      "            " 

6.65 

" 

270,247       " 

4.50 

" 

2,155,464       "            "      • 

4.32 

" 

5,089,290       " 

1.70 

" 

2,544,645       " 

0.85 

M 

3.  FOR  ASPHALT  AND  SHALE  OIL  INDUSTRY. — The  production  of 
asphalt  and  bituminous  rock  in  the  United  States  in  recent  years  has 
been,  according  to  "Mineral  Resources  of  the  United  States  for  1909  ": 


Short  tons. 

1906     96,532 

1907     154,906 

1908     122,156 


Value. 

$1,019,102 

2,103,698 

1,572,616 


The  importations  of  asphaltum  of  various  kinds,  according  to 
eral  Resources  of  the  United  States  for  1909,"  have  been: 


:Min- 


Short  tons. 

1908     147,685 

1909     148,744 


Value. 

$587,698 

646,655 


52        PETROLEUM,  MINERAL  OIL,  AND  ASPHALT  INDUSTRY. 


The  estimated  quantity  of  bituminous  shale  distilled  in  recent  years 
in  Scotland,  according  to  Boverton  Redwood  ("Petroleum  and  its  Prod- 
ucts," 2d  ed.,  vol.  i,  p.  419),  was: 


1890  2,180,483  tons. 

1891  2,337,932  " 

1892  2,077,076  " 


1900  2,282,221  tons. 

1901  2,354,356  " 

1902  2,107,534  " 


The  following  are  the  figures  for  the  German  mineral-oil  trade  for 
1892-93.  Forty-eight  shale-oil  works  were  operated  with  1297  ovens 
and  1067  workmen;  20,521,453  hectolitres  of  coal  were  distilled,  and 
1,195,892  centners  of  tar  and  5,651,566  centners  of  coke  were  obtained. 
The  tar  was  valued  at  4,345,422  marks  and  the  coke  at  1,643,748  marks. 
On  working  up  the  tar  there  were  obtained  159,250  centners  of  hard 
and  soft  paraffin,  102,306  centners  of  solar  oil,  and  623,691  centners 
of  different  paraffin  oils.  The  value  of  the  combined  products  was 
11,098,496  marks. 


RAW  MATERIALS.  53 


CHAPTER    II. 

INDUSTRY     OF     THE     FATS     AND     FATTY     OILS. 

I,  Raw  Materials. 

1.  OCCURRENCE  OF  THE  MATERIALS. — The  fats  and  fatty  oils  are  of 
both  vegetable  and  animal  origin.  They  occur  not  only  widely  spread 
through  these  two  kingdoms  of  nature,  but  constitute  often  the  larger 
proportion  by  weight  of  the  material  in  which  they  are  found.  No  part 
of  the  plant  seems  to  be  entirely  wanting  in  fat,  although  that  found 
in  the  leaves  is  more  of  a  wax-like  character  than  the  oil  obtained  from 
the  seeds  and  fruit;  in  the  animal,  fats  are  present  in  all  tissues  and 
organs  and  in  all  fluids  with  the  exception  of  the  normal  urine.  In 
plants  the  percentage  of  fat  seems  to  be  in  inverse  ratio  to  the  percentage 
of  starch  and  sugar,  and  ranges  from  sixty-seven  per  cent,  in  the  Brazil 
nut  to  one  per  cent,  in  barley.  While  the  oil-bearing  plants  are  far  too 
numerous  to  allow  of  a  complete  enumeration  here,  it  will  be  desirable 
to  state  first  the  occurrence  of  those  technically  most  important,  and 
afterwards  to  examine  those  physical  and  chemical  differences  which  lie 
at  the  basis  of  their  different  uses.  Similarly  the  most  important  animal 
oils  and  fats  will  first  be  enumerated. 

(a)  VEGETABLE  OILS,  FATS,  AND  WAXES. — Castor  oil  (oleum  ricini, 
ricinus-oel)  is  extracted  by  pressure  or  heat  from  the  seeds  of  the 
Ricinus  communis,  originally  from  the  East.  It  is  a  thick  oil,  of  specific 
gravity  .9669  at  15°  C.,  colorless  or  yellowish,  transparent,  of  mild 
taste,  but  becoming  rancid  on  long  exposure  to  air,  miscible  with  alcohol 
and  ether,  and  easily  saponifiable.  The  shelled  seeds  yield  from  forty  to 
fifty  per  cent,  of  the  oil. 

Cotton-seed  oil  (oleum  gossypii  seminum,  baumwollen-samen-oel)  is 
obtained  by  pressure  from  the  hulled  seeds  of  the  several  species  of 
Gossypium,  or  cotton-plant.  The  raw  oil  is  brownish-red  in  color,  some- 
what viscid,  of  specific'  gravity  .920  to  .930  at  15°  C.,  and  separates 
some  palmitin  at  from  6°  C.  to  12°  C.  The  refined  oil  has  a  straw- 
yellow  color,  or  is  colorless,  of  pleasant  nutty  flavor;  specific  gravity, 
.9264  at  15°  C. ;  boils  at  about  600°  F.,  and  congeals  at  about  50°  F.  for 
summer-  and  32°  F.  for  winter-pressed.  Even  at  the  ordinary  tempera- 
ture, cotton-seed  oil  deposits  "stearine  "  on  standing.  The  finer  brands 
of  cotton-seed  oil  intended  for  edible  and  culinary  purposes  are  freed 
from  this  "stearine  "  by  chilling  or  simply  by  allowing  the  oil  to  stand 
for  some  time  in  large  storage  tanks.  It  possesses  slight  drying  proper- 
ties, and  is  saponifiable,  but  is  chiefly  used  as  a  substitute  or  adulterant 
of  lard  and  olive  oils.  The  hulled  seeds  yield  from  eighteen  to  twenty 
per  cent,  of  the  crude  oil. 

Hemp-seed  oil  (oleum  cannabis,  hanf-oel)  is  obtained  from  the  seeds 
of  the  Cannabis  sativa,  or  common  hemp.  It  has  a  mild  odor  but  a 
mawkish  taste,  and  greenish-yellow  color,  turning  brown  with  age.  Its 


54  INDUSTRY  OF   THE  FATS  AND  FATTY  OILS. 

specific  gravity  at  15°  C.  is  .9276.  It  is  freely  soluble  in  boiling  alco- 
hol. Has  weaker  drying  properties  than  linseed  oil,  but  is  used  in  paint 
and  varnish  manufacture  and  in  making  soft  soaps.  The  seeds  contain 
some  thirty  per  cent,  of  the  oil. 

Linseed  oil  (oleum  lini,  lein-oel)  is  pressed  from  the  seeds  of  the 
Linum  usitatissimum,  or  flax-plant.  The  oil  differs  in  quality  according 
to  the  method  of  its  production.  By  cold  pressure  is  obtained  twenty  to 
twenty-one  per  cent,  of  a  pale,  tasteless  oil,  which  is  used  in  cooking  as 
a  substitute  for  lard  or  butter  in  Russia  and  Poland.  By  warm  pressure 
is  obtained  twenty-seven  to  twenty-eight  per  cent,  of  an  amber-colored 
or  dark-yellow  oil.  It  is,  when  fresh,  somewhat  viscid,  but  as  a  drying 
oil  it  gradually  absorbs  oxygen  and  becomes  thick  and  eventually  dry 
and  hard.  The  specific  gravity  of  the  fresh  oil  is  .935  at  15°  C.  It  is 
used  almost  exclusively  in  the  preparation  of  paints,  varnishes,  printers' 
ink,  and  "oil-cloth."  (See  p.  113.) 

Poppy-seed  oil  (oleum  papaveris,  mohn-oel)  is  obtained  from  the 
seeds  of  the  opium  poppy  by  pressure,  is  of  pale-yellow  color,  and 
slightly  sweetish  taste.  Specific  gravity,  .925  at  15°  C.  The  cold-drawn 
,  oil,  the  oil  of  the  first  pressing,  is  almost  colorless,  or  very  pale  golden 
yellow;  this  is  the  "white  poppy-seed  oil  "  of  commerce.  The  second 
quality,  expressed  at  a  higher  temperature,  is  much  inferior,  and  con- 
stitutes the  "red  poppy-seed  oil  "  of  commerce.  It  is  used  for  salads, 
paints,  soaps,  and  to  adulterate  olive  and  almond  oils.  The  seeds  yield 
from  forty-seven  to  fifty  per  cent,  of  oil. 

Walnut  oil  (huile  de  noix,  wallnuss-oel)  is  obtained  from  the  seeds 
of  the  common  walnut-tree,  Juglans  regia.  The  fruit  to  be  pressed 
should  be  fully  ripe  and  kept  for  several  months  before  being  pressed, 
as  the  fresh  seeds  yield  a  turbid  oil.  The  cold-drawn  oil  is  very  fluid, 
almost  colorless,  or  of  a  pale  yellow-greenish  tint,  and  has  a  pleasant 
smell  and  agreeable  nutty  taste ;  the  hot-pressed  oil,  on  the  other  hand, 
has  a  greenish  tint  and  an  acrid  taste  and  smell.  Walnut  oil  is  a  very 
good  drying  oil,  and  at  least  equal  if  not  superior  in  that  respect  to  lin- 
seed oil.  It  is  chiefly  used  by  artists  for  paints,  as  it  dries  to  a  varnish 
film  less  liable  to  crack  than  the  film  of  linseed-oil  varnish.  Moreover, 
the  better  brands  of  walnut  oil  being  almost  colorless,  it  is  preferred  to 
any  other  oil  for  white  paints. 

Sunflower  oil  (huile  de  soleil,  sonnenblumen-oel)  is  obtained  from  the 
seeds  of  the  sunflower  (Helianthus  annuus),  and  is  a  limpid  pale-yellow 
oil  of  mild  taste  and  pleasant  smell.  Specific  gravity,  .925  at  15°  C.  It 
belongs  to  the  class  of  drying  oils,  but  dries  more  slowly  than  linseed 
oil.  The  cold-drawn  oil  is  also  used  in  Russia  for  culinary  purposes, 
while  that  expressed  at  a  higher  temperature  is  employed  in  soap-making 
and  for  the  manufacture  of  varnishes. 

Almond  oil  (oleum  amygdalae,  mandel-oel)  is  the  fixed  oil  obtained 
from  both  the  sweet  and  the  bitter  almond.  The  former  contains  the 
more  oil,  but  the  latter  is  cheaper,  and  the  residual  cake  can  be  utilized 
for  the  preparation  of  the  essential  oil  of  bitter  almonds.  The  oil  is 
odorless,  agreeable  to  the  taste,  and  of  yellow  color.  Specific  gravity, 
.919  at  15°  C.  It  is  used  in  pharmacy  and  medicine  and  in  soap-making. 


RAW  MATERIALS.  55 

Corn  oil  (maize  oil,  mais-oel)  is  obtained  from  the  seeds  of  the  maize 
or  Indian  corn,  either  by  expressing  the  seed  before  it  is  employed  for 
the  manufacture  of  starch,  or,  where  the  corn  has  been  fermented  for  the 
production  of  alcohol,  by  recovering  it  from  the  residue  of  the  fermen- 
tation vats.  Prepared  by  the  former  process,  it  is  of  a  pale-yellow  or 
golden-yellow  color,  whereas  the  oil  obtained  by  the  latter  process  is 
reddish  brown.  Specific  gravity,  .921  to  .924  at  15°  C.  The  oil  has 
slight  drying  properties  only.  It  is  used  for  soap-making,  in  the  manu- 
facture of  artificial  rubber,  for  varnishes,  and,  when  refined,  as  salad  oil. 

Sesame  oil  (gingili  oil,  teel  oil,  sesam-oel)  is  obtained  from  the  seeds 
of  the  Sesamum  orientale  and  Sesamum  indicum.  The  oil  possesses  a 
yellow  color,  is  free  from  odor,  and  has  a  pleasant  taste.  The  cold- 
drawn  oil  is  therefore  considered  equal  to  olive  oil  for  table  use.  It  has 
very  slight  drying  properties.  Specific  gravity,  .923  at  15°  C.  In  addi- 
tion to  its  use  as  an  edible  oil,  the  inferior  grades  are  used  in  soap- 
making  and  as  burning  oil. 

Ben  oil  (oleum  balatinum,  behen-oel)  is  obtained  by  expression  from 
the  seeds  of  the  several  species  of  Moringia.  Colorless,  odorless  oil,  not 
readily  turning  rancid.  It  is  used  by  perfumers  for  extracting  odors 
and  for  lubricating  clocks  and  light  machinery. 

Cacao  butter  (oleum  theobromatis)  is  obtained  from  seeds  or  nibs  of 
Theobroma  cacao.  Nearly  white  fat,  with  pleasant  odor  and  taste. 
Fuses  at  86°  F.  (30°  C.).  Specific  gravity,  .945  to  .952.  It  is  used  for 
cosmetics  and  for  pharmaceutical  preparations. 

Cocoa-nut  oil  (oleum  cocois,  kokos-oel)  is  obtained  from  the  dried 
pulp  (copra)  of  the  cocoa-nut  by  expression.  An  oil  of  the  consistency 
of  butter,  fusing  at  73°  to  80°  F.  (22.7°  to  26.6°  C.).  When  fresh,  is 
white  in  color  and  of  sweet  taste  and  agreeable  odor,  but  easily  becomes 
rancid.  It  is  easily  saponified,  even  in  the  cold.  It  is  used  in  the  manu- 
facture of  candles  and  padded  soaps.  (See  p.  70.) 

Colza  and  rape  oils  (oleum  brassicae,  riiboel)  are  practically  identical. 
They  are  extracted  from  the  several  varieties  of  Brassica  campestris. 
The  seeds  are  called  cole-seed  or  rape-seed.  The  term  "colza  oil  "  is 
generally  applied  to  refined  rape  oil.  The  crude  oils  are  used  as  lubri- 
cating oils,  and  are  of  dark,  yellow-brown  color.  Kefined  and  freed  from 
albumen  and  mucilage,  they  become  bright-yellow.  The  specific  gravity 
of  the  refined  oil  is  .9132  at  15°  C.  Rape  oil  is  used  for  lamps,  for 
lubricating  machinery,  and  for  adulterating  both  almond  and  olive  oils. 

Olive  oil  (oleum  olivarum,  oliven-oel)  is  expressed  from  the  fruit  of 
Olea  Europcea.  It  differs  greatly  in  quality  according  to  the  method 
by  which  it  is  obtained.  The  purest  is  nearly  inodorous,  pale-yellow, 
with  pure  oily  taste.  Specific  gravity,  .918  at  15°  C.  Does  not  decom- 
pose or  become  rancid  easily,  and  congeals  at  32°  F.  to  a  granular  solid 
mass.  The  percentage  of  oil  amounts  to  thirty-two  per  cent.,  of  which 
twenty-one  per  cent,  is  furnished  by  the  pericarp,  and  the  remainder, 
which  is  inferior,  by  the  seed  and  woody  matter  of  the  fruit.  It  is  used 
extensively  as  an  article  of  food  or  condiment,  in  pharmacy,  as  an  illu- 
minant  and  lubricant,  and  in  soap-making.  The  lowest  grade,  ' '  tournant 


56  INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 

oil,"  has  a  high  per  cent,  of  free  fatty  acids  and  readily  emulsifies  with 
sodium  carbonate  solution. 

Arachis  oil  (peanut  oil,  erdnuss-oel).  This  oil  is  obtained  from 
earth-nuts,  the  seeds  of  Arachis  hypogwa.  The  cold-drawn  oil  of  the  first 
expression  is  nearly  colorless,  and  has  a  pleasant  taste  resembling  the 
flavor  of  kidney  beans.  Specific  gravity,  .917  at  15°  C.  The  best  qual- 
ities of  the  oil  are  used  for  table  oil  and  the  inferior  grades  for  soap- 
making. 

Palm  oil  (oleum  palmse,  palm-oel)  is  obtained  from  the  fruit  of 
several  species  of  palm.  The  fresh  palm  oil  has  an  orange-yellow  tint, 
a  sweetish  taste,  and  an  odor  resembling  violets.  Its  specific  gravity  is 
about  .945.  Its  consistency  is  that  of  butter  or  lard.  It  ordinarily  be- 
comes rancid  rapidly,  and  hence  usually  contains  free  acid.  It  is  used 
in  candle-  and  soap-making,  and  also  to  color  and  scent  ointments, 
pomades,  soap  powders,  etc. 

Carnauba  wax  is  obtained  from  the  leaves  of  the  carnauba  palm, 
Copernicia  cerifera  of  Brazil.  Its  specific  gravity  is  .999  and  its  melting 
point  185°  F.  (84°  C.).  It  is  brittle  and  of  yellowish  color.  It  is  exten- 
sively used  in  the  manufacture  of  candles. 

Japan  wax  is  obtained  by  boiling  the  berries  of  several  trees  of  the 
genus  Rhus,  from  incisions  in  the  stems  of  which  flows  the  famous  Japan 
lacquer  varnish.  It  is  properly  a  fat,  as  it  consists  almost  entirely  of 
glyceryl  palmitate.  Its  specific  gravity  is  .999  and  melting  point  120°  F. 
(49°  C.).  When  freshly  broken,  the  fractured  surface  is  almost  white  or 
slightly  yellowish-green  and  the  odor  tallow-like.  It  is  used  for  mixing 
with  beeswax  in  the  manufacture  of  candles  and  in  the  manufacture  of 
wax-matches. 

Myrtle  wax,  a  solid  fat  obtained  by  pressure  from  the  berries  of 
myrica  cerifera.  Specific  gravity  1.005  at  15°  C. ;  fusing  point  45°  to 
46°  C.  It  is  used  as  a  substitute  for  beeswax  and  particularly  in  candle- 
making. 

(6)  ANIMAL  OILS,  FATS,  AND  WAXES. — Neat's- foot  oil.  Prepared 
from  the  feet  of  oxen  collected  from  the  slaughter-houses.  It  is  a  clear, 
yellowish  oil  of  specific  gravity  .916  at  15°  C.  It  does  not  congeal  until 
below  32°  F.,  and  is  not  liable  to  become  rancid.  Of  great  value  as  a 
lubricant,  and  used  for  softening  leather  and  grinding  of  metals. 

Butter  fat  is  the  oily  portion  of  the  milk  of  mammalia,  but  in  prac- 
tice the  term  is  restricted  to  that  obtained  from  cows'  milk.  The  pure 
fat  constitutes  from  eighty-five  to  ninety-four  per  cent,  of  the  finished 
butter.  The  pure  fat  has  a  specific  gravity  of  .910  to  .914,  and  its  melt- 
ing point  varies  from  85°  to  92°  F.  For  fuller  account  of  manufac- 
tured butter,  see  under  milk  (p.  281.) 

Lard  and  lard  oil  (adeps,  schweine-schmalz)  is  the  fat  of  the  pig 
melted  by  gentle  heat  and  strained.  The  crude  lard  is  white,  granular, 
and  of  the  consistency  of  a  salve,  of  faint  odor  and  sweet,  fatty  taste. 
Its  specific  gravity  is  .938  to  .940  at  15°  C.  Exposed  to  the  air  it  becomes 
yellowish  and  rancid.  When  pressed  at  32°  F.,  it  yields  sixty-two  parts 
of  colorless  lard  oil  and  thirty-eight  parts  of  compact  lard.  The  lard  is 


RAW  MATERIALS.  57 

used  in  cooking,  the  lard  oil  for  greasing  wool,  as  a  lubricant  and  an 
illuminant. 

Tallow  and  tallow  oil  (sevum,  talg).  Tallow  is  the  name  given  to  the 
fat  extracted  from  ' '  suet, ' '  the  solid  fat  of  oxen,  sheep,  and  other  rumi- 
nants. The  quality  of  the  tallow  varies  according  to  the  food  of  the 
cattle  and  other  circumstances,  dry  fodder  inducing  the  formation  of  a 
hard  tallow.  Its  melting  point  varies  from  115°  to  121°  F.  The  best 
qualities  are  whitish,  but  it  has  in  general  a  yellowish  tint.  Beef  tallow 
contains  about  sixty-six  per  cent,  of  solid  fat  and  thirty-four  per  cent, 
of  olein  or  tallow  oil ;  mutton  tallow  contains  about  seventy  per  cent,  of 
solid  fat  and  thirty  per  cent,  of  tallow  oil.  The  oil  is  used  chiefly  in 
the  manufacture  of  soaps  and  the  harder  tallow  for  candle-making. 

Bone  fat  is  a  whitish-yellow  fat  obtained  by  boiling  bones  or  extrac- 
tion of  the  same  with  benzin,  and  is  used  in  soap-making. 

Cod-liver  oil  (oleum  jecoris  ceselli,  leberthran)  is  an  oil  ranging  in 
color  according  to  the  method  of  its  preparation  from  pale-straw  to  dark- 
brown,  and  of  specific  gravity  .923  to  .924  or  even  .930  at  15°  C.  The 
finer  qualities  are  used  for  medicinal  purposes,  the  darker  for  tanners' 
and  curriers'  use. 

Menhaden  oil  is  obtained  from  the  Alosa  menhaden,  a  kind  of  her- 
ring. Is  used  for  soap-making  and  tanning,  and,  when  pure,  as  a  sub- 
stitute for  cod-liver  oil. 

Shark  oil  is  prepared  from  the  livers  of  various  species  of  shark.  It 
is  the  lightest  of  the  fixed  oils,  the  specific  gravity  ranging  from  .865  to 
.876.  It  is  used  in  the  adulteration  of  cod-liver  oil  and  for  tanning. 

Whale  oil  (train  oil)  is  extracted  from  the  blubber  of  the  common 
or  Greenland  whale.  Is  yellow  or  brownish  in  color  and  of  disagreeable 
odor.  Specific  gravity  .920  to  .931.  It  is  used  for  illumination  and  for 
soap-making. 

Sperm  oil  is  procured  from  the  deposits  in  the  head  of  the  sperm 
whale.  In  the  living  animal,  the  solid  spermaceti  is  held  in  solution  in 
the  liquid  sperm  oil;  when  the  liquid  becomes  cold  the  spermaceti  sepa- 
rates out.  The  oil  is  very  limpid,  relatively  free  from  odor,  and  burns 
well  in  lamps.  Specific  gravity,  .875.  It  is  used  as  a  lubricant  on 
account  of  its  low  cold  test  and  its  viscosity,  and  as  an  illuminant. 

Spermaceti  (cetaceum,  walrath)  is  the  solid  wax  separated  out  from 
the  accompanying  oil.  It  is  yellowish  at  first,  but  when  purified  is  white, 
brittle,  and  scaly.  Its  specific  gravity  is  .943  at  15°  C. ;  melting  point, 
43°  to  49°  C.  It  is  only  slightly  soluble  in  alcohol,  benzene,  and  petro- 
leum-ether, but  easily  soluble  in  ether,  chloroform,  and  carbon  disul- 
phide.  It  is  used  in  the  manufacture  of  candles  and  in  pharmaceutical 
preparations. 

Wool  grease  (woll-fett,  lanolin,  or  adeps  lance).  Sheep's  wool  con- 
tains a  large  amount  of  fatty  matter  of  a  peculiar  character.  It  contains 
free  fatty  acids,  esters  of  cholesterol  and  isocholesterol,  and  the  free 
alcohols  just  named.  When  purified  from  fatty  acids  it  yields  lanolin, 
which  has  the  property  of  taking  up  large  quantities  of  water  in  an 
emulsion  and  is  used  extensively  in  medicine.  The  esters  are  true  waxes 
and  not  glycerides. 


58  INDUSTRY  OF   THE  FATS  AND  FATTY  OILS. 

Beeswax  (cera  flava,  bienenwachs)  is  the  substance  of  which,  the  cells 
of  the  honey-bee  are  constructed.  The  crude  melted  wax  is  a  tough, 
compact  mass  of  yellow  or  brownish  color,  granular  structure,  faint  taste, 
and  honey-like  odor.  When  bleached  it  becomes  white. .  Specific  gravity 
.959  to  .969;  melting  point  62°  to  64°  C.  It  is  used  in  making  candles, 
ointments,  and  pomades. 

Chinese  wax  (insect  wax)  is  deposited  by  an  insect,  Coccus  cerifera, 
upon  the  Chinese  ash-tree.  It  is  a  white,  very  crystalline,  and  brittle 
wax,  resembling  spermaceti  in  appearance.  Specific  gravity  .973  at  15° 
C. ;  fuses  at  82°  to  83°  C.  It  is  slightly  soluble  in  alcohol  and  ether,  very 
soluble  in  benzene.  It  is  used  in  candle-making. 

2.  PHYSICAL  AND  CHEMICAL  CHARACTERS  OF  THE  DIFFERENT  OILS  AND 
PATS. — (a)  Physical  Properties. — Most  of  the  vegetable  fats  are  liquid 
at  ordinary  temperatures,  because  of  the  relatively  high  percentage  of 
olein  they  contain.  Cocoa-nut  oil,  palm  oil,  cacao  butter,  and  a  few 
others  have  a  buttery  consistence  on  account  of  the  palmitin  present. 
The  fats  of  animals  feeding  on  straw  and  hay  are  solid,  because  of  the 
stearin  present ;  the  fats  of  carnivorous  animals  are  all  softer ;  the  fat  of 
fishes  is  liquid  at  ordinary  temperatures,  and  somewhat  differently  con- 
stituted chemically.  The  solid  waxes,  both  vegetable  and  animal,  are 
in  general  differently  constituted  from  the  softer  fats. 

The  fats  and  oils  are  almost  insoluble  in  water  (if  the  water  contains 
albumen,  gum,  or  alkaline  carbonates  in  solution  they  readily  form  an 
emulsion  with  it  on  shaking);  alcohol  only  dissolves  them  sparingly; 
ether,  carbon  disulphide,  chloroform,  benzene,  turpentine  oil,  fusel  oil, 
and  acetone  dissolve  them  readily. 

On  exposure  to  the  air,  the  fats,  and  particularly  the  fatty  oils,  absorb 
oxygen.  The  heat  developed  by  this  oxidation  at  times  suffices  to  inflame 
wool  and  cotton  tissues  soaked  with  the  oil.  The  oils  which  absorb  oxy- 
gen in  this  way  become  thick,  and  finally  dry  to  translucent  resinous 
masses.  Such  oils  are  called  "drying  oils,"  and  are  used  in  painting 
and  varnish-making.  (See  p.  112.)  The  specific  gravity  of  all  the  fats 
and  oils  is  less  than  unity,  although  the  vegetable  waxes  are  only  very 
slightly  less. 

The  boiling-points  of  the  oils  and  fats  cannot  in  general  be  taken  as 
distinctive,  as  many  of  them  begin  to  decompose  when  distilled  under 
ordinary  pressure.  Their  fusing  and  congealing  points  are  more  im- 
portant ;  particularly  in  the  case  of  oils  used  as  lubricants  does  the  latter 
denote  the  different  value  of  the  oil  for  use  at  low  temperatures. 

(&)  Chemical  Composition  of  the  Oils,  Fats,  and  Waxes. — The  fatty 
oils,  as  distinguished  from  the  mineral  oils  (see  p.  13)  and  the  volatile 
oils  (see  p.  103),  belong  to  the  class  of  compound  ethers.  They  are  salt- 
like  bodies,  composed  of  characteristic  acids  (oleic,  palmitic,  and 
stearic),  known  as  fatty  acids,  in  combination  with  an  alcohol  or  base. 
In  most  cases  the  base  is  the  triatomic  alcohol  glycerine,  so  that  the  oils 
are  said  to  be  glycerides  of  the  several  fatty  acids.  Some  few,  known 
as  waxes,  do  not  contain  glycerine,  but  a  monatomic  alcohol  in  combina- 
tion with  the  fatty  acid.  Most  of  the  animal  and  vegetable  fats  contain 
the  three  proximate  constituents,  olein,  palmitin,  and  stearin,  the  com- 


RAW  MATERIALS.  59 

binations  of  oleic,  palmitic,  and  stearic  acids  respectively  with  gly- 
cerine. In  the  more  liquid  oils  the  olein  predominates,  in  the  more  solid 
palmitin  or  stearin.  The  so-called  ' '  drying  oils  ' '  contain  a  different  acid 
— linoleic  acid — in  combination  with  glycerine.  The  fish  oils  contain  a 
variety  of  the  lower  fatty  acids  and  some  solid  unsaponifiable  alcohols 
like  cholesterin.  The  most  satisfactory  classification  of  the  oils  and  fats 
is  that  of  A.  H.  Allen,*  which  is  here  given  in  abstract. 

I.  Olive    Oil    Group. — Vegetable    oleins.     Vegetable    non-drying    oils.     Lighter 
than  Groups  III,  IV  and  V.     Yield  solid  elaidins  with  nitrous  acid.     Includes  olive, 
almond,  earth-nut  and  ben  oils. 

II.  Rape  Oil  Group, — Xon-drying  oils  from  the  cruciferce.    Yield  pasty  elaidins 
and  have  higher  saponification  equivalents  than  Group  I.     Includes  rape  seed,  colza, 
and  mustard  oils. 

III.  Cotton-seed  Oil  Group. — Intermediate  between  drying  and  non-drying  oils. 
Undergo   more  or  less   drying  on  exposure.      Yield   little   or   no   elaidin.      Includes 
cotton-seed,  sesame,  sunflower,  maize,  soja-bean,  hazel-nut,  and  beech-nut  oils. 

IV.  Linseed    Oil    Group. — Vegetable    drying    oils.     Yield    no    elaidin.     Of   less 
viscosity  than  the  non-drying  oils.     Includes  linseed,  hemp-seed,  poppy-seed,  niger- 
seed,  and  walnut  oils. 

V.  Castor   Oil    Group. — Medicinal    oils.     Very   viscous   and    of    high    density. 
Includes  castor  and  croton  oils. 

VI.  Cacao  Butter  Group. — Solid  vegetable  fats.     Do  not  contain  notable  quan- 
tities of  glycerides  of  lower  fatty  acids.     Includes  palm  oil,  cacao  butter,  nutmeg 
butter,  and  shea  butter. 

VII.  Cocoa-nut   Oil   Group. — Solid  vegetable   fats,   in   part  wax-like.     Several 
contain  notable  proportions  of  the  glycerides  of  lower  fatty  acids.     Includes  cocoa- 
nut  oil,  palm-nut  oil,  laurel  oil,  Japan  wax,  and  myrtle  wax. 

VIII.  Lard  Oil  Group. — Animal  oleins.     Do  not  dry  notably  on  exposure,  and 
give  solid  elaidins  with  nitrous  acid.     Includes  neat's-foot  oil,  bone  oil,  lard  oil, 
and  tallow  oil. 

IX.  Tallow  Group. — Solid  animal  fats.     Predominantly  glycerides  of  palmitic 
and  stearic  acid,  although  butter  contains  lower  glycerides.     Includes  tallow,  lard, 
bone  fat,  wool  fat,  butter  fat,  oleomargarine,  and  manufactured  stearin. 

X.  Whale  Oil  Group. — Marine  animal  oils.     Characterized  by  offensive  odor 
and  reddish-brown  color  when  treated  with  caustic  soda.     Includes  whale,  porpoise, 
seal,  menhaden,  cod-liver,  and  shark-liver  oils. 

XL  Sperm  Oil  Group. — Liquid  waxes.  These  are  not  glycerides  but  ethers  of 
monatomic  alcohols.  Yield  solid  elaidins.  Includes  sperm  oil,  bottle-nose  oil,  and 
dolphin  oil. 

XII.  Beesicax  Group. — Waxes  proper.  Are  esters  of  higher  monatomic  alco- 
hols, with  higher  fatty  acids  in  free  state.  Includes  spermaceti,  beeswax,  Chinese 
wax,  and  carnauba  wax. 

3.  EXTRACTION  OF  THE  EAW  MATERIALS  AND  PURIFICATION  OF  THE 
SAME. — The  method  of  extraction  of  the  oils  and  fats  is,  of  course,  deter- 
mined to  a  considerable  degree  by  their  physical  condition.  Solid  fats, 
like  tallow  and  lard,  are  obtained  free  from  the  enclosing  membranes  by 
melting  the  finely-chopped  material  and  drawing  off  the  fat  in  the 
melted  state;  animal  oils  are  extracted  mainly  by  boiling  out  with 
water;  oil  fruits  and  seeds  are  ground  fine,  and  then  the  oil  obtained 
by  submitting  the  meal  to  pressure,  either  cold  or  with  the  aid  of  heat, 
or  the  oil  is  extracted  by  solvents  like  carbon  disulphide  and  petroleum 
ether. 

*  Commercial  Organic  Analysis,  4th  ed.,  vol.  ii,  p.  64. 


60  INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 

In  the  extraction  of  fats  by  the  process  of  melting,  three  forms  of 
procedure  are  followed:  (1),  the  so-called  "cracklings  "  process,  a  melt- 
ing over  direct  fire,  known,  too,  as  the  "dry  melting  ";  (2),  the  melting 
over  direct  fire  with  the  addition  of  dilute  sulphuric  acid,  known  as  the 
"moist  melting;"  and  (3),  the  melting  by  the  aid  of  steam.  In  the  first 
process,  a  little  water  is  added  and  the  tallow  or  other  chopped  fat  is 
heated  in  open  vessels.  The  mixture  of  fat  globules  and  water  at  first 
gives  it  a  milky  appearance,  but,  as  soon  as  the  water  is  driven  off,  the 
cell  membranes  shrivel  more  and  more  together,  forming  the  cracklings, 
and  the  fat  appears  as  a  clear,  fused  liquid.  A  constant  stirring  is  re- 
quired in  order  to  prevent  the  fragments  of  membrane  from  sticking  to 
the  sides  or  bottom  of  the  vessel  and  burning.  The  melted  fat  is  drained 
from  the  cracklings  by  passing  through  metallic  sieves,  and  cracklings 
afterwards  pressed  in  suitable  presses  to  recover  the  adhering  fat,  which 
forms  a  second  quality  tallow.  A  raw  tallow  yields  on  the  average 
eighty  to  eighty-two  per  cent,  of  drained  oil  and  ten  to  fifteen  per  cent, 
of  cracklings;  a  very  pure  kidney  fat  will  yield,  however,  ninety  per 
cent,  and  over  of  drained  fat. 

In  the  second  process,  now  generally  followed,  to  one  hundred  kilos, 
of  tallow,  twenty  kilos,  of  water  mixed  with  one-half  to  one  and  one- 
half  kilos,  of  concentrated  sulphuric  acid  is  added.  The  sulphuric  acid 
attacks  and  destroys  the  cell-membranes  rapidly  when  heated,  and  so 
allows  of  the  liberation  of  the  fat.  In  this  process,  as  in  the  last,  pro- 
vision must  be  made  for  preventing  the  escape  into  the  air  of  the  un- 
healthy and  offensive  odors  coming  from  the  melting  of  the  impure 
tallow.  The  escaping  vapors  are  in  part  condensed  and  part  burned 
under  the  kettles.  In  the  third  process,  that  of  melting  by  steam,  the 
steam  may  be  directly  introduced  into  the  fat  mass  or  indirectly  used  by 
the  aid  of  coils  of  pipes. 

The  tallow  rendering  by  steam  is  illustrated  in  the  apparatus  of  Wil- 
son, shown  in  Fig.  18.  The  steam  enters  through  the  perforated  pipe  G, 
under  the  perforated  false  bottom.  The  plate  F  having  been  shut  down 
tight  upon  the  opening  E,  the  vessel  is  two-thirds  filled  with  the  tallow 
and  steam  applied.  The  pressure  is  allowed  to  rise  to  three  and  a  half 
atmospheres  (fifty-two  and  a  half  pounds  per  square  inch)  and  kept  at 
this  for  some  ten  hours.  The  condensed  water  collects  under  the  false 
bottom  and  can  be  drawn  off  when  necessary.  The  melted  tallow  is  then 
run  off  from  the  stopcocks,  PP,  and  the  cracklings  finally  discharged 
through  the  opening  E. 

Some  acid  may  be  added  to  the  fat  or  in  the  Evrard  process,  instead 
of  acid,  caustic  soda,  which  has  the  advantage  of  combining  with  the 
noxious  volatile  acids  evolved. 

The  extraction  of  lard  takes  place  by  similar  methods  to  those 
employed  for  tallow,  but  at  lower  temperatures  and  more  readily. 

For  the  extraction  of  animal  oils,  like  fish  oils,  the  method  of  boiling 
out  with  water  is  generally  employed,  elevation  of  temperature  and  pro- 
longed heating  being  avoided  as  much  as  possible  in  the  case  of  the  finer 
medicinal  oils. 


RAW  MATERIALS. 


61 


For  oil-bearing  fruits  and  seeds,  the  methods  of  obtaining  oil,  as 
already  mentioned,  are  expression,  either  cold  or  by  the  aid  of  heat,  and 
that  of  extraction  by  solvents. 

For  the  expression  of  oils,  the  carefully  cleaned  seeds  are  first  crushed 
to  break  the  shells  or  kernels  and  then  ground  to  fine  meal.  The  crush- 
ing is  done  very  generally  in  oil-seed  mills  of  the  the  type  known  as 
"edge-runners,"  where  the  two  stones  or  metal  wheels  are  made  to 
revolve  on  a  stone  foundation  on  which  the  oil  seeds  are  placed,  and 

FIG.  18. 


from  which  any  excess  of  oil  may  flow.  A  much  more  perfect  crushing 
is  possible  in  this  mill  than  in  those  in  which  stamps  are  used.  They 
are  then  slightly  heated  for  the  double  purpose  of  coagulating  any 
plant  albumen  and  making  the  oil  more  liquid.  In  the  case  of  the  best 
medicinal  or  table  oils  all  heat  is  avoided  and  cold-pressed  oils  only 
taken.  The  meal  is  then  repeatedly  pressed.  The  result  of  the  first 
pressing  is  often  called  "virgin  oil,"  and  is  of  better  color  and  taste 
than  the  later  lots.  The  pressing  is  done  with  hydraulic  presses  under 
pressures  rising  to  300  atmospheres  (equalling  about  two  tons  to  the 
square  inch).  The  crushed  oil  seed  is  placed  in  woolen  or  cotton  cloths, 
usually  covered  in  by  bags  of  horse-hair,  and  then  placed  between  the 
press-plates.  Following  the  cold  pressing,  or  at  once  in  the  case  of  oil- 


62 


INDUSTRY  OF   THE  FATS  AND  FATTY  OILS. 


bearing  seeds  of  lesser  value,  the  crushed  seed  is  warmed  in  a  steam- 
jacketed  kettle,  which  is  provided  with  mixing  appliances,  and  then 
delivered  through  a  mixing  box  into  bags  or  cloths  for  the  hot  pressing. 
The  so-called  Anglo-American  open  press,  in  which  this  expression  is 
effected,  is  shown  in  Fig.  19.  The  other  process,  that  of  extraction  of 
the  oil  by  solvents,  is  capable  of  yielding  a  much  larger  amount  of  oil 
than  is  obtained  by  pressure,  but  has  been  more  or  less  opposed  on  several 
grounds.  The  solvents  employed  are  carbon  disulphide  and  petroleum- 
ether.  The  former  is  the  better  solvent,  is  used  at  a  lower  temperature, 

FIG.  19. 


and  is  easily  recovered  from  the  solution  afterwards  without  leaving  any 
appreciable  odor  adhering  to  the  oil.  It,  however,  dissolves  coloring 
matter  and  resin  from  the  seed  as  well  as  oil,  and  so  introduces  impurity, 
and  when  not  perfectly  pure,  it  leaves  sulphur  impurities  also  in  the 
oil.  The  other  solvent  does  not  dissolve  so  much  coloring  matter  or 
resin,  communicates  no  odor,  and  leaves  no  sulphur  or  other  residues  in 
the  oil,  and  so  can  be  used  for  fine  table  oils,  if  necessary.  It  requires 
a  higher  temperature,  however,  and,  condensing  on  the  surface  of  water 
instead  of  under  it,  like  carbon  disulphide,  requires  more  complicated 
distillation  and  condensing  apparatus.  At  the  present  time  the  carbon 
disulphide  is  more  generally  used.  A  solvent  ^superior  to  either  is 
carbon  tetrachloride,  which  is  coming  into  increasing  use.  Like  carbon 
disulphide,  it  is  heavier  than  water  arid  insoluble  in  the  same,  but  its 


RAW  MATERIALS.  63 

chief  merit  is  its  entire  uninflammability.  It  is  still  rather  too  expen- 
sive for  general  use,  and,  like  chloroform,  its  vapors  have  a  certain  nar- 
cotic effect.  Moreover,  in  the  presence  of  moisture,  it  attacks  iron  and 
copper,  and  hence  has  to  be  used  in  lead-lined  extraction  vessels.  The 
objection  first  urged  against  the  extraction  of  oil  by  solvents,  that  they 
left  the  oil-cake  valueless  for  cattle  food  because  of  the  too  complete 
extraction  of  the  oil,  is  now  met  by  the  oil  men,  who  leave  eight  to  ten 
per  cent,  of  fat  or  oil  in  palm-nut  or  other  oil-cake. 

The  expressed  or  extracted  oils  are  in  many  cases  in  quite  a  crude 
condition,  containing  both  suspended  and  dissolved  impurities  of  various 
kinds.  To  purify  them  for  use,  even  in  soap-making,  some  treatment  is 
generally  necessary.  Often  simple  but  prolonged  subsidence  suffices  if 
the  impurities  are  only  suspended.  Instead  of  subsidence,  it  may  be 
necessary  at  times  to  use  filtration  through  cotton  wadding,  animal  char- 
coal or  fuller's  earth.  If  both  subsidence  and  filtration  fail  to  clear 
the  oils,  it  is  necessary  to  adopt  chemical  treatment,  as  the  impurities  in 
time  ferment  and  develop  a  permanent  rancidity  or  deterioration  of 
the  oil.  The  first  process  to  note  is  that  of  Thenard,  to  add  gradually 
one  to  two  per  cent,  of  sulphuric  acid  to  oil  previously  heated  to  about 
100°  F.  and  mix  by  thorough  agitation,  followed  by  settling  and  drawing 
off  from  the  acid  sludge.  The  sulphuric  acid  both  takes  up  the  water 
that  holds  the  impurities  in  solution  and  chars  the  impurities  themselves. 
The  treatment  with  acid  is  to  be  followed  by  a  thorough  washing  with 
warm  water  'and  final  filtration.  Cogan  's  process  follows  the  addition 
of  sulphuric  acid  by  that  of  steam.  Instead  of  sulphuric  acid,  caustic 
alkalies  are  sometimes  used  as  in  the  Evrard  process  (see  p.  60),  which 
is  chiefly  applied  to  colza  and  rape  oils.  In  this  case,  the  caustic  soda 
saponifies  a  small  quantity  of  the  oil,  and  the  soap  carries  down,  mechan- 
ically, all  impurities,  leaving  the  oil  perfectly  clear.  Too  prolonged 
agitation  may,  however,  make  an  emulsion  of  soap  and  oil,  which  sepa- 
rates with  difficulty.  R.  von  Wagner  proposed  the  use  of  zinc  chloride 
instead  of  sulphuric  acid,  as  this  chars  the  impurities  without  attacking 
the  oil.  The  zinc  chloride  is  used  in  concentrated  solution  of  1.85 
specific  gravity,  about  one  and  one-half  per  cent,  being  taken  and  thor- 
oughly agitated  with  the  oil.  After  the  zinc  chloride  solution  is  with- 
drawn, the  oil  is  well  washed  with  water  and  filtered.  Tannin  is  also 
used  to  clear  some  oils,  which  it  effects  by  coagulating  the  albumen. 

Cotton-seed  oil  is  always  colored  by  some  resin,  which  is  removed  by 
treatment  with  alkali,  which  saponifies  the  resin  and  the  free  acids  of  the 
crude  oil,  converting  them  into  a  mucilaginous  soap  which  separates  in 
dark-colored  flakes  when  the  oil  is  heated.  This  produces  a  light  yellow 
oil,  which  may  be  further  purified  by  being  heated  to  from  150°  to  200° 
F.  in  kettles  with  fuller's  earth,  after  which  it  is  filter-pressed. 

Still  more  energetic  methods  for  purifying  oils  are  the  oxidation 
methods,  using  "chloride  of  lime  "  or  bichromate  of  potash,  and  sul- 
phuric or  hydrochloric  acids  as  applied  to  palm  oil. 

The  use  of  hydrogen  peroxide  solution  has  recently  been  tried  for 
the  bleaching  of  oils,  with  the  best  of  results.  Four  or  five  per  cent,  of 


64  INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 

a  ten  per  cent,  solution  will  generally  suffice  if  repeatedly  shaken  up 
with  the  oil  to  be  treated.  Sodium  and  calcium  peroxides  operate  in  the 
same  way. 

Ozone-carriers,  like  ferrous  sulphate  solution,  will  also  bleach  in  the 
presence  of  sunlight.  This  method  is  often  applied  with  linseed  oil. 

IE.  Processes  of  Treatment. 

1.  SAPONIFICATION  OF  PATS. — The  composition  of  the  proximate  prin- 
ciples, olein,  palmitin,  and  stearin,  which  make  up  the  bulk  of  the  fats 
proper,  was  first  established  by  the  researches  of  Chevreul  in  1823.  Their 
decomposition  can  be  effected  in  a  number  of  ways,  by  the  action  of 
bases  like  the  alkalies  and  some  metallic  oxides,  by  the  action  of  sul- 
phuric acid  liberating  the  fatty  acids;  and  by  the  action  of  water  alone, 
when  aided  by  heat  and  pressure. 

Chevreul  at  first  used  alkalies,  patenting  that  process  in  1825,  in 
conjunction  with  Gay-Lussac,  but  this  procedure  was  given  up  already 
in  1831,  when  Ad.  de  Milly  replaced  the  alkalies  by  lime.  This  was 
used  exclusively  for  a  number  of  years,  but  was  followed  in  1854  by 
the  independent  discovery  of  Tilghman  and  Berthelot  of  the  method 
of  decomposing  by  the  use  of  hot  water  superheated  by  high  pressure. 
Melsens  also  proposed  the  same  process  substantially  a  little  later.  In 
consequence  of  the  danger  connected  with  the  high  temperature  and 
pressure,  this  process  is  not  carried  out  any  longer  in  its  original  shape, 
but  is  now  replaced  by  the  "autoclave  "  process,  mentioned  later.  In 
1841  Dubrunfaut  found  that  if  neutral  fats  were  treated  first  with  sul- 
phuric acid,  and  then  boiled  with  water,  the  fatty  acids  might  be  dis- 
tilled in  an  atmosphere  of  superheated  steam  without  decomposition. 
This  constituted  the  distillation  process.  It  was  extensively  used  in  Eng- 
land. Wilson  and  Gwynne  found  it  possible,  with  proper  application 
of  the  superheated  steam  and  regulation  of  the  temperature  (290°  to 
315°  C.),  to  dispense  with  the  sulphuric  acid,  and  to  decompose  the 
fats  and  then  distil  them  without  any  decomposition.  This  process  is 
now  used  on  a  large  scale  by  the  Price  Candle  Company  in  England. 
Still  later,  Bock,  of  Copenhagen,  found  that  if  the  membranous  cellu- 
lar tissue  that  enclosed  the  fat  be  decomposed  by  a  preliminary  treat- 
ment with  sulphuric  acid  and  the  charred  tissue,  which  by  oxidation 
becomes  heavier  than  the  fat  and  sinks  through  it,  be  removed,  the  pure 
fat  could  be  decomposed  by  boiling  with  water  in  open  tanks.  The  sepa- 
rated fatty  acids  are  so  pure  in  color  that  washing  suffices,  and  no  dis- 
tillation is  necessary. 

These  several  processes  have  been  in  time  modified  and  amalgamated 
until  now  only  three  or  four  processes  are  practically  followed  on  a  large 
scale : 

(1)  The  saponification  by  alkalies  used  exclusively  in  soap-making 
and  yielding  a  soda  or  potash  salt  of  the  fatty  acid.     (See  SOAPS,  p.  68.) 

(2)  A  combination  of  the  lime  and  hot-water  processes,  known  as 
Milly 's  "autoclave  process,"  in  which  two  to  four  per  cent,  of  lime  is 


PROCESSES  OF  TREATMENT.  65 

made  to  do  the  work  of  saponification,  for  which  8.7  per  cent,  is  the- 
oretically needed,  and  for  which  fourteen  to  seventeen  per  cent,  was  at 
first  used.  The  saponification  is  carried  out  in  the  presence  of  water  in 
strong,  closed,  metallic  vessels,  at  a  temperature  of  172°  C.  One  form 
of  such  vessel  for  the  saponification  by  lime  under  pressure  that  has  been 
much  used  is  an  egg-shaped  cylinder.  At  present  the  form  of  the  vessel 
in  use  is  more  generally  that  of  a  sphere,  which  stands  the  eight  to  ten 
atmospheres  internal  pressure  better.  The  lime  soap,  technically  called 
11  rock,"  after  its  separation  is  decomposed  by  sulphuric  acid,  four 
parts  of  acid  to  each  three  parts  of  lime  used  being  taken.  After  the 
complete  subsidence  of  the  calcium  sulphate  the  free  fat  acids  are  thor- 
oughly washed  with  water  and  steam. 

(3)  The  sulphuric  acid  saponification,  followed  by  distillation.    This 
process  is  almost  exclusively  followed  in  England.     The  amount  of  sul- 
phuric acid  used  has  gradually  been  diminished,  as  it  is  found  that  a 
relatively  smaller  percentage  will  suffice.     For  offal  fats  some  twelve 
per  cent,  is  now  used,  for  tallow  nine  per  cent.,  and  for  palm  oil  six 
per  cent.     The  decomposition  generally  requires  some  hours  at  a  tem- 
perature varying  from  120°  to  170°  C.     Milly  modified  this  process  by 
using  a  smaller  quantity  of  sulphuric  acid  .(two  to  three  and  a  half 
per  cent.),  which  he  allows  to  act  at  a  temperature  of  150°  C.  for  two 
to  three  minutes  only,  and  then  boils  with  water.    In  this  way  the  larger 
portion  of  the  fat  acids  are  white  enough  to  be  used  for  candle-making 
without  previous  distillation,  while  some  twenty  per  cent,  only  of  them 
needs  to  be  distilled.     The  form  of  apparatus  for  the  distillation  of  the 
free  fatty  acids  produced  in  the  sulphuric  acid  saponification  is  shown 
in  Fig.  20.    T  is  the  superheater,  from  which  steam  at  300°  C.  is  passed 
into  the   retort  D,  which   is   previously   filled  to  three-fourths  of  its 
capacity  with  melted  tallow  through  the  supply-pipes  V  V.     The  fatty 
acids  distil  out  of  the  tube  U,  are  condensed  by  the  worm  8,  and  col- 
lected by  the  receiver  K. 

(4)  The  superheated-steam  process  of  Wilson  and  Gwynne,  before 
alluded  to.     This  is  at  present  carried  out  in  both  England  and  Ger- 
many.   The  apparatus  devised  by  Mr.  G.  F.  Wilson,  of  the  Price  Candle 
Company,  of  London,  is  shown  in  Fig.  21.     The  fat,  previously  heated 
in  the  flat  vessel,  A,  by  the  waste-heat  from  the  superheater  below,  flows 
into  the  retort  C.    This  retort  must  be  kept  at  from  290°  to  315°  C.,  and 
to  this  end  is  covered  entirely  above;  the  superheated  steam  at  315°  C. 
comes  into  the  retort  by  the  tube  to  the  side,  and  some  twenty-four  to 
thirty-six  hours  is  necessary  to  decompose  and  distil  off  a  charge  of  fat. 
If  the  temperature  falls  below  310°  C.,  the  decomposition  is  extremely 
slow,  while  much  above  315°  C.,  acrolein  forms  from  the  decomposition 
of  the  glycerine.     The  decomposition  of  fats  by  enzymes  has  also  been 
made  a  working  method  quite  recently.     The  enzyme  contained  in  the 
castor-oil  bean  has  been  found  best  adapted  for  this.     An  emulsion  of 
fat,  water,  ten  per  cent,  of  ground  castor-oil  bean,  and  a  small  amount 
of  free  acid  are  used,  when  the  decomposition  proceeds  rapidly. 

Before  proceeding  with  the  special  processes  of  soap-making,  stearine- 

5 


66 


INDUSTRY  OF   THE  FATS  AND  FATTY  OILS. 


candle  manufacture,  oleomargarine  and  glycerine  production,  it  will  be 
well  to  present  in  schematic  way  the  complete  treatment  of  a  fat  such  as 
tallow.  The  accompanying  scheme  is  taken  from  Post's  "Chemische 


FIG.  20. 


Technologic,"  and  shows  the  processes  applicable  and  the  products  re- 
sulting from  the  technical  utilization  of  tallow. 

2.  PRACTICAL  SOAP-MAKING. — In  the  application  of  the  first  method 
of  saponification  of  fats,  that  of  the  use  of  alkalies,  we  have,  of  course, 


FIG.  21. 


always  a  potash  or  a  soda  salt  of  the  fatty  acid  formed,  which,  singly  or 
admixed,  constitute  the  products  known  as  soaps'.  A  very  great  variety 
of  soaps  are  known,  the  appearance  and  properties  of  which  vary  accord- 
ing to  the  method  of  manufacture.  We  may  classify  the  several  methods 
of  manufacture  as  follows: 


PROCESSES  OF  TREATMENT. 


67 


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LEIC  ACID  (about  23.5  kilos.) 
brought  into  commerce  as: 
leic  Acid, 
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>ft  Soaps  (Potash  Soaps). 

0 

SOLID  FAT  ACIDS 

(about  4  kilos.).  (a 
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P' 

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LIQUID  FATTY  ACIDS  (aboi 
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68  INDUSTRY  OF   THE  FATS  AND  FATTY  OILS. 

(1)  Boiling  the  fats  in  open  vessels  (coppers)  with  indefinite  quan- 
tities of  alkaline  lyes  until  products  of  definite  character  are  gotten. 
These  are   (a),  soft  soaps,  in  which  the  glycerine  is  retained,  potash 
being  the  base;   (6),  the  so-called  "hydrated  soaps,"  with  soda  for  a 
base,  in  which  the  glycerine  is  retained,  and  of  which  "marine  "  soap 
may  be  taken  as  the  type;  (c),  hard  soaps,  with  soda  for  a  base,  in  which 
the  glycerine  is  eliminated,  comprising  three  kinds, — curd,  mottled,  and 
yellow  soaps. 

(2)  Acting  upon  the  fats  with  the  precise  quantity  of  alkali  neces- 
sary for  saponification  without  the  separation  of  any  waste  liquor,  the 
glycerine  being  retained  in  the  soap.     This  includes  (a)  soaps  made  by 
the  "cold  process,"  and  (6)  soap  made  under  pressure. 

(3)  Direct  union  of  the  fatty  acids,  as  in  "red  oil  "  and  caustic 
alkali,  or  alkaline  carbonate. 

The  general  outlines  of  these  methods  may  be  indicated: 
In  the  manufacture  of  soft  soaps  the  drying  oils  are  preferably  used. 
In  England  whale,  seal,  and  linseed  oil  are  chiefly  used,  in  Continental 
Europe  hemp-seed,  linseed,  rape-seed,  poppy,  and  train  oils,  and  in  the 
United  States  cotton-seed  oil  and  oleic  acid.  A  potash  lye  containing 
some  carbonate  is  used,  and  frequently  a  portion  of  the  potash  is  re- 
placed by  soda.  The  soft  soaps,  after  being  boiled  to  the  necessary 
degree,  are  not  salted,  so  that  the  glycerine  and  any  excess  of  alkali 
remains  in  the  soap.  For  use  in  wool-scouring  this  excess  of  alkali  is, 
however,  unsuited,  so  that  neutral  soft  soaps  are  specially  sought  to  be 
obtained.  The  method  of  making  ' '  hydrated  "  or  ' '  filled  ' '  soaps  is  very 
similar  to  that  of  soft  soaps.  Fatty  matter  and  soda  are  run  into  the 
copper,  and  the  whole  is  boiled  together,  care  being  taken  to  avoid  an 
excess  of  alkali  at  first;  when  saponification  has  taken  place,  lye  is  cau- 
tiously added  until  the  soap  tastes  very  faintly  of  alkali,  when  the  soap 
is  ready  to  be  transferred  to  the  frames,  without  any  salting  or  sepa- 
rating of  the  mixture.  Marine  soap,  for  use  with  sea-water,  is  made  in 
this  way,  and  is  entirely  cocoa-nut  oil  soap.  The  well-known  Eschweger 
soap  is  also  made  by  this  general  method  from  a  mixture  of  cocoa-nut 
oil  and  other  fats,  saponified  either  separately  or  together,  and  con- 
taining the  glycerine  and  water  in  the  soap  mass. 

The  manufacture  of  true  hard  soaps,  which  still  constitute  the  great 
bulk  of  those  made  in  England  and  the  United  States,  requires  more 
time  and  care  than  the  varieties  just  mentioned.  Melted  fat  and  a 
quantity  of  soda  lye  of  about  11°  B.,  equal  to  one-fourth  that  needed 
for  complete  saponification,  are  simultaneously  run  into  the  copper  and 
steam  turned  on.  The  "soap-copper,"  as  shown  in  Fig.  22,  is  an  iron 
kettle,  or  series  of  kettles,  set  in  masonry,  and  equipped  with  pipes 
for  both  open  and  closed  steam,  and  provided  with  an  outlet  for  the 
discharge  of  the  waste  lyes  when  required.  They  may  be  used  in  series, 
or  extra  large  single  ones  used.  Strong  lye  should  not  be  used  at  this 
first  stage,  or  saponification  will  not  take  place.  When  the  mixture 
becomes  homogeneous,  lye  of  20°  to  25°  B.,  in  amount  equal  to  that  taken 
before,  may  be  cautiously  added.  It  is  now  boiled  until  a  sample  taken 


PROCESSES  OF  TREATMENT. 


69 


out  has  a  firm  consistence  between  the  fingers.  Common  salt  or  a  brine 
of  24°  B.  is  now  run  in.  A  small  sample  removed  on  a  spatula  or  trowel 
should  now  allow  clear  liquor  to  run  from  it.  The  boiling  is  then 
stopped,  and  the  copper  should  be  allowed  to  stand  at  least  two  or  three 
hours.  The  contents  now  divide  themselves  into  two  portions,  the 
upper  consisting  of  soap-paste,  containing  water,  and  the  lower  con- 
sisting of  "spent  lye,"  holding  in  solution  common  salt  and  all  the 
impurities  of  the  liquors,  together  with  glycerine.  It  should  contain 
no  caustic  soda  and  no  soap.  After  removing  the  spent  lye  from  below, 
the  rest  of  the  caustic  soda  lye  is  run  in  and  the  soap  boiled  up  again. 
At  this  stage  the  rosin  is  usually  added  for  rosin  or  yellow  soaps.  The 
boiling  is  now  continued  until  the  frothing  mixture  boils  quietly  and 

FIG.  22. 


becomes  clear,  the  process  being  known  as  "clear  boiling."  The  copper 
is  then  boiled  with  open  steam  and  a  small  quantity  of  lye  of  12°  B. 
allowed  to  run  in  until  the  soap  separates  in  flakes  and  feels  hard  when 
cold,  technically  called  "making  the  soap."  Boiling  is  still  continued 
for  several  hours  to  insure  complete  saponification,  and  it  is  then  allowed 
to  separate  and  harden.  This  procedure  yields  a  curd  soap  if  no  rosin 
has  been  added.  If,  after  a  soap  is  "made,"  the  lye  in  which  it  is  sus- 
pended is  concentrated  to  a  point  short  of  that  necessary  to  produce 
hard  curd  soap,  and  it  is  then  transferred  to  the  cooling  frames  with  a 
certain  quantity  of  lye  entangled  in  it,  these  insoluble  particles  will, 
during  the  solidification  of  the  soap,  collect  together  and  produce  the 
appearance  known  as  "mottling;"  and  the  effect  is  heightened  by  the 
partial  crystallization  of  the  soap.  The  lye  remaining  in  the  cavities 
between  the  curds  makes  mottled  soaps,  the  most  suitable  and  really 
economical  for  washing  clothes,  etc.,  in  hard  waters,  although  not  for 
toilet  purposes.  Mottling  is  sometimes  added,  as  the  peculiar  greenish 
mottle,  which  becomes  red  on  exposure,  characteristic  of  Marseilles  and 
Castile  soaps,  is  produced  by  adding  some  solution  of  ferrous  sulphate 


70  INDUSTRY  OF   THE   FATS  AND  FATTY  OILS. 

to  the  copper  when  the  soap  is  nearly  finished  (about  four  ounces  of  the 
salt  to  one  hundred  pounds  of  the  fat)  ;  the  precipitated  iron  protoxide 
suspended  in  the  soap  is  greenish,  but  it  becomes  peroxide  in  contact 
with  air,  to  which  the  change  to  a  red  color  on  exposure  is  due.  Yellow 
soaps  are  made  from  tallow  and  rosin,  the  proportion  of  rosin  varying 
from  one-sixth  of  the  total  to  an  equal  weight,  or  even  more,  according 
to  the  quality  of  the  soap  desired.  In  the  presence  of  the  sodium  oleate 
from  the  tallow,  the  rosin  acids  saponify  readily  and  coalesce  to  form  a 
very  uniform  soap. 

In  smooth  or  "cut  "  soaps  water  or  thin  lye  is  added  to  the  contents 
of  the  copper  before  the  soap  separates  finally  to  form  the  curd,  and  is 
taken  up  in  considerable  amount,  giving  a  smooth  yet  firm  surface  to 
the  soap,  instead  of  the  hard,  granular  surface  of  the  curd  soap. 

The  so-called  "cold  process  "  requires  the  use  of  exact  weights  of 
well-refined  fats  and  of  caustic  soda  of  a  given  specific  gravity,  the 
quantities  being  such  that  only  just  enough  soda  is  present  to  completely 
saponify  the  fat.  The  materials  are  allowed  to  stand  together  for  a  short 
time  and  then  thoroughly  mixed  in  a  copper  provided  with  steam,  agi- 
tating paddles,  and  kept  at  a  temperature  of  not  over  120°  F.  The 
reaction  proceeds  rapidly,  and  after  some  fifteen  minutes  the  materials 
have  so  far  united  that  they  will  not  separate  on  standing,  although 
the  complete  saponification  of  the  materials  may  require  days.  They 
are  then  run  out  into  the  cooling-frames.  It  is  obvious  that  soaps  made 
in  this  way  retain  all  the  glycerine  originally  combined  with  the  fatty 
acids  disseminated  through  the  particles  of  soap,  and  belong  to  the  class 
known  as  "filled"  or  "padded"  soaps,  mentioned  before.  (See  p.  68.) 

When  cocoa-nut  oil  alone  is  used,  the  temperature  of  working  in 
this  cold  process  need  not  be  higher  than  75°  F.  for  summer  and  90°  F. 
in  winter;  if  one-half  tallow,  104°  to  108°  F.;  and  if  two-thirds  tallow, 
113°  to  120°  F.  is  necessary. 

Mixtures  of  cocoa-nut  oil  and  other  fats  are  frequently  saponified  in 
this  way,  the  free  acid  of  the  cocoa-nut  oil  readily  starting  the  process 
of  saponification.  A  well-refined  tallow  can,  however,  be  saponified  in 
this  way  too,  and  mixtures  of  tallow  and  rosin  worked  up  also  into 
yellow  filled  soaps. 

This  combination  of  cocoa-nut  oil  with  tallow  and  rosin  can  also 
take  up  on  its  saponification  large  quantities  of  water-glass  and  similar 
"filling  "  material,  so  that  a  very  large  yield  of  smooth  filled  soap  is 
obtained.  Thus  a  mixture  of  one  hundred  kilos,  of  cocoa-nut  oil, 
seventy-five  to  eighty  kilos,  of  rosin,  three  hundred  kilos,  of  water- 
glass,  one  hundred  to  one  hundred  and  fifty  kilos,  of  tallow,  and  two 
hundred  and  forty  kilos,  soda  lye  of  33°  B.,  will  make  eight  hundred 
kilos,  of  a  finished  soap. 

Saponification  under  pressure  has  also  been  frequently  tried,  the 
object  being  to  shorten  the  time  required  for  open  boiling.  In  this 
case  the  quantity  of  alkali  used  must  be  accurately  adjusted  to  the  fat 
to  be  saponified,  the  glycerine  is  retained  in  the  ultimate  product.  The 
process  is  carried  out  in  an  autoclave  or  pressure-boiler,  the  tempera- 


PROCESSES  OF  TREATMENT.  71 

ture  is  allowed  to  rise  to  about  310°  F.  (154.4°  C.),  equivalent  to  a 
steam-pressure  of  sixty-three  pounds  to  the  square  inch,  and  kept  at 
this  for  an  hour,  when  the  contents  are  discharged  into  a  cooling-frame. 

There  remains  to  be  noted  the  process  of  soap-making  in  which  we 
start  not  with  a  fat,  but  with  the  free  fatty  acids,  as  in  the  "red  oil  " 
or  crude  oleic  acid  obtained  in  stearine  candle  manufacture.  (See  p. 
74.)  These  oleic  soaps,  as  they  are  called,  are  made  preferably  from 
the  oleine  acid  resulting  from  the  saponification  of  tallow  or  palm  oil  by 
the  lime  process.  That  obtained  in  the  distillation  process  is  not  so  well 
adapted  for  use  here.  The  oleic  acid  may  be  saponified  either  with  car- 
bonate or  with  caustic  alkali.  The  former  process  has  the  disadvantage 
that  the  escaping  carbonic-acid  gas  causes  a  strong  frothing  which 
easily  leads  to  boiling  over.  One  hundred  kilos,  of  the  oleic  acid  obtained 
in  the  lime-saponification  yield  one  hundred  and  fifty  to  one  hundred 
and  sixty  kilos,  of  soap.  The  acid  obtained  by  distillation  always  yields 
somewhat  less.  Frequently  the  oleic  acid  before  saponifying  is  changed 
by  nitrous  acid  into  the  isomeric  elaidic  acid,  which  is  as  hard  as  tallow, 
and  from  which  a  very  fine  soap  can  then  be  made  resembling  tallow 
soap,  and  capable  of  being  worked  at  will  into  a  curd  soap  or  a  cut 
soap.  If  it  be  made  with  carbonate  of.  soda,  the  copper  is  filled  to  one- 
third  its  capacity  with  the  oleic  acid  and  the  calculated  amount  of  half- 
crystallized  and  half-calcined  soda  added,  little  by  little,  while  the 
heating  and  thorough  agitation  of  the  liquid  is  kept  up.  When  the  soap 
becomes  thick  and  all  foaming  has  ceased,  the  soap  is  filled  at  once  into 
the  forms  to  cool.  The  portion  of  crystallized  soda  used  supplies  all 
the  water  needed  for  the  saponification. 

In  saponification  with  caustic  alkali,  a  strong  lye  (25°  B.)  is  taken. 
No  emulsion  forms,  but  a  lumpy,  mortar-like  mass,  which,  however,  as 
the  alkali  is  more  fully  taken  up  and  the  lye  becomes  weaker,  gradually 
goes  over  into  ordinary  soap-paste.  The  soap  is  separated  by  the  addi- 
tion of  a  strong  lye  instead  of  salting  it. 

After  the  finishing  of  the  soap  in  the  copper,  it  may  either  be  put 
direct  into  the  cooling  frame,  or  it  may  be  transferred  to  mixing  tanks, 
known  as  "  crutchers, "  where  various  solutions  or  substances  are  incor- 
porated with  it  prior  to  its  being  allowed  to  solidify. 

Soap-frames  are  of  two  kinds,  according  as  it  is  desired  to  cool  the 
soap  slowly  or  quickly.  "When  slow  cooling  is  required,  as  is  always 
the  case  with  mottled  soap,  wooden  frames,  usually  of  pine,  are  em- 
ployed. These  are  built  up  in  horizontal  sections,  nine  to  twelve  inches 
deep,  each  section  lined  with  thin  sheet-iron,  as  shown  in  Fig.  23.  Most 
curd  and  all  yellow  soaps  are  cooled  rapidly  in  cast-iron  frames  of  any 
desired  shape  and  size.  Such  an  iron  soap-frame  is  illustrated  in  Fig. 
24.  The  sides  and  ends  of  the  frame  are  easily  removed  after  the  thor- 
ough solidification  of  the  soap,  and  the  block  is  then  left  upon  the  truck, 
which  served  as  the  bottom  of  the  frame.  It  is  now  ready  for  the  cut- 
ting into  slabs  and  bars.  This  is  now  almost  universally  done  by  ma- 
chinery, and  the  truck  containing  the  hardened  block  is  run  at  once 
into  the  large  frame  containing  the  cutting  wires.  Such  a  frame,  al- 


72 


INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 


FIG.  23. 


though  of  smaller  size,  and  used  for  slabs  of  soaps  only,  is  shown  in 
Fig.  25.  The  best  piano-forte  wire  is  necessary  for  these  "Cutting 
frames,  as  the  tension  is  very  great  when  the  soap  is  pressed  through 
the  wires. 

While  the  soaps  thus  far  spoken  of  are  adapted  for  general  or 
laundry  purposes  there  is  a  distinct  class  of  soaps  known  as  toilet  soaps. 

As  these  are  to  be 
applied  to  the  skin 
they  must  answer 
other  requirements, 
the  most  important 
of  which  is  that 
they  shall  not  con- 
tain any  free  alkali. 
Some  dermatologists 
even  demand  that 
there  shall  always 
be  some  unsaponified  fat.  We  may  distinguish  transparent  soaps,  re- 
melted  soaps,  and  milled  soaps. 

Transparent  soaps  may  be  made  either  by  the  spirit  process,  in 
which  case  the  stock  soap  is  dissolved  in  alcohol,  the  solvent  almost  all 
distilled  off,  and  the  mixture  then  run  into  frames  to  gelatinize  and 
solidify  by  gradual  evaporation  of  the  remaining  alcohol,  or  the  cold 
glycerine  process.  In  this  case  the  warm  fatty  materials  employed  (of 
which  castor  oil  is  generally  a 
large  ingredient  on  account  of 
the  readiness  with  which  it 
saponifies)  are  intimately  mixed 
with  soda  ley;  soluble  coloring 
matters  and  essential  oils  or 
other  scenting  material  are  then 
stirred  in  and  the  whole  allowed 
to  stand.  The  glycerine  which 
forms  on  saponification  tends  to 
cause  the  soap  to  take  a  trans- 
lucent appearance.  Perfect 
transparency  can  be  obtained 
by  the  addition  of  more  gly- 
cerine, or  what  accomplishes  the 
same  result,  and  is  cheaper, 
cane-sugar.  This  latter  ingredient,  however,  makes  the  soap  irritating 
to  sensitive  skins. 

In  the  remelting  of  soaps,  followed  chiefly  in  England,  several  stock 
soaps  may  be  mixed  together,  coloring  and  scenting  materials  added, 
and  the  mass  heated  in  a  steam- jacketed  pan.  If  ,the  mixture  is  rapidly 
agitated,  enough  air-bubbles  may  be  worked  in  to  enable  the. cake  of 
soap  to  float  in  water,  even  after  compression  in  the  stamping  press, 
producing  a  toilet  soap  which  "  floats  "  on  water.  The  addition  of  some 


FIG.  24. 


PROCESSES  OF  TREATMENT. 


73 


pearlash  (potassium  carbonate)  is  also  made  at  times  to  improve  the 
lathering  power  of  the  soap,  but  such  soaps  are  alkaline  and  injurious 
to  delicate  skins.  The  finest  toilet  soaps,  however,  are  made  by  "mill- 
ing," a  process  first  carried  out  in  France.  The  bars  of  stock  soap  are 
first  "stripped,"  or  cut  into  slices  by  a  slicing  machine.  The  chips  are 
dried  in  a  warm  air-chamber  until  only  a  few  per  cent,  of  water  remains, 
and  then  ground  between  heavy  horizontal  rollers  of  the  milling  ma- 
chine. At  this  stage  the  various  coloring  and  perfuming  ingredients 
are  added,  or  unguents  like  lanolin  and  vaseline.  The  thoroughly  mixed 
material  is  then  put  into  a  cylindrical  barrel,  in  which  it  is  compressed 
by  a  piston  and  comes  out  as  a  continuous  bar,  which  is  cut  into  lengths 


FIG.  25. 


and  stamped  into  cakes.  The  advantages  of  this  method  are,  first,  that 
inasmuch  as  no  artificial  heat  is  applied,  delicate  flower  perfumes,  etc., 
can  be  readily  incorporated  with  the  soap  mass  which  it  would  be  impos- 
sible to  use  with  a  remelted  soap,  because  the  heat  would  dissipate  or 
destroy  the  odoriferous  matter;  and,  secondly,  that  as  the  resulting 
tablets  usually  contain  only  a  small  quantity  of  water,  a  given  weight  of 
soap-cake  or  tablet  generally  contains  a  much  larger  quantity  of  actual 
soap  than  another  cake  of  the  same  weight  prepared  by  remelting  or  by 
the  cold  process,  whilst  being  harder  and  stiffer,  it  lasts  longer,  wasting 
less  rapidly  during  use.  Spherical  cakes  and  wash-balls  are  finished  by 
turning  and  polishing  in  a  kind  of  lathe.  Sometimes  the  polishing  is 
finished  by  the  use  of  a  cloth  dipped  in  alcohol. 

Shaving  creams  are  made  by  the  cold  process  from  refined  lard  and 
caustic  potash,  adding  cocoa-nut  oil  in  small  amount  to  facilitate  the 
making  of  lather. 


74 


INDUSTRY  OF   THE  FATS  AND  FATTY  OILS. 


3.  STEARIO  ACID  AND  CANDLE  MANUFACTURE. — For  the  extraction 
of  stearic  acid,  the  washed  fatty  acids  (p.  65)  are  heated  to  the  melting 
point  and  run  into  dishes  or  troughs  made  of  tin,  as  shown  in  Fig.  26. 
These  are  placed  in  a  room,  the  temperature  of  which  is  kept  at  68°  to 
86°  F.  (20°  to  30°  C.),  and  left  for  two  to  three  days,  or  until  the  con- 
tents have  granulated,  as  the  palmitic  and  stearic  acids  crystallize,  when 
the  dishes  are  emptied  into  canvas  or  woollen  bags,  which  are  carefully 
deposited  between  the  plates  of  an  upright  hydraulic  press,  as  shown 
in  Fig.  27.  Pressure  is  now  exerted,  increasing  in  degree  until  the  flow 


FIG.  27 


FIG.  26. 


of  the  liquid  oleic  acid  ceases.  The  hard,  thin  cakes  of  crude  stearic 
acid  so  obtained  are  then  melted  down  again  with  steam,  and  after  set- 
tling, the  melted  acid  run  into  the  tin  dishes  and  placed  aside  to  cool. 
The  temperature  of  the  cooling-room  in  this  case  should  be  higher  than 
before,  or  about  86°  F.  (30°  C.).  The  blocks  of  stearic  acid  gotten  are 
ground  to  meal,  filled  in  bags  of  hair  or  wool,  and  then  submitted  to  a 
second  pressure,  in  a  horizontal  hydraulic  press,  the  plates  of  which  can 
be  heated.  In  this  press,  a  pressure  of  six  tons  per  square  inch,  at  tem- 
peratures of  from  104°  to  120°  F.  (40°  to  49°  C.),  is  reached.  The  cakes 
so  obtained  are  melted  by  steam,  a  little  wax  being  sometimes  added  to 
destroy  the  crystalline  structure  of  the  stearic  acid,  which  somewhat 
unfits  it  for  candle-making. 


PROCESSES  OF  TREATMENT.  75 

The  yield  of  stearic  acid  obtained  varies  according  to  the  fat  used 
and  the  process  of  saponification  employed.  F.  A.  Sarg's  Sons  (Vienna) 
use  three  per  cent,  of  lime  under  a  pressure  of  ten  atmospheres,  and  get 
ninety-five  per  cent,  of  crude  fat  acids  and  thirty  per  cent,  of  glycerine 
water  (5°  to  6°  B.),  and  a  final  yield  of  forty-five  per  cent,  stearic  acid, 
fifty  per  cent,  of  oleic  acid,  and  five  to  six  per  cent,  of  glycerine.  In 
England,  with  the  sulphuric  acid  and  distillation  process,  they  get  sixty 
to  seventy  or  even  seventy-five  per  cent,  of  fat  acids  suitable  for  candle- 
making,  although  inferior  to  that  obtained  in  the  lime  process. 

Palm  oil  is  now  used  in  enormous  quantities  for  the  production  of 
palmitic  acid  at  Price's  Candle  Company's  works,  as  well  as  by  almost 
every  candle  manufacturer  in  Great  Britain,  about  twenty-five  thousand 
tons  being  annually  consumed.  In  many  continental  countries  a  prohib- 
itive duty  prevents  its  employment.  From  this  palmitic  acid  the  finest 
composite  candles  are  made  by  hot-pressing  the  distilled  palmitic  acid. 

Palmitic  acid  for  candle-making  is  also  made  commercially,  according 
to  a  process  of  St.  Cyr-Radisson,  by  fusing  oleic  acid  with  a  great  excess 
of  caustic  potash,  the  products  of  the  reaction  being  potassium  palmi- 
tate,  potassium  acetate,  and  hydrogen.  As  carried  out  in  Marseilles,  the 
oleic  acid  and  potash  lye  of  41°  B.  are  put  into  an  autoclave  provided 
with  a  mechanical  agitator,  and  heated  until  steam  ceases  to  be  given 
off,  when  the  open  manhole  is  closed,  and  the  heat  continued  until  554° 
F.  (290°  C.)  is  reached.  Decomposition  now  commences,  and  much 
hydrogen  is  given  off  through  an  escape-tube  set  in  the  lid  of  the  boiler. 
At  608°  F.  (320°  C.)  the  odor  of  the  evolved  gas  suddenly  changes,  and 
destructive  distillation  begins.  This  is  arrested  by  blowing  in  steam  at 
once,  and  the  contents  are  run  out.  The  potassium  palmitate  is  then 
washed,  decomposed  with  sulphuric  acid,  the  free  acid  washed  and 
distilled.  The  product  of  the  distillation  is  white,  and  burns  excellently 
when  made  into  candles. 

In  the  manufacture  of  candles,  the  first  operation  is  the  preparation 
of  the  wick.  For  dip-candles  the  wick  is  twisted,  for  others  it  is  plaited, 
and  the  kind  of  plaiting  must  also  vary  according  to  the  material  used. 
Stearine  candles  require  a  moderately  tightly-braided  wick,  paraffin 
candles  an  extra  tight  braid,  and  for  spermaceti  and  wax,  on  the  other 
hand,  the  braids  are  measurably  loose.  After  being  twisted,  or  plaited, 
the  wicks  are  dried  and  then  dipped  into  a  pickling  liquor,  which  is  to 
retard  combustion  and  help  in  the  destruction  of  the  ash.  The  pickle 
usually  consists  of  a  solution  of  boracic  acid,  ammonium  phosphate,  or 
ammonium  chloride.  Three  plans  of  candle-making  are  at  present  in 
use, — dipping,  moulding,  and  pouring.  The  first  is  employed  for  com- 
mon tallow  candles,  which  are  accordingly  called  "dips."  Under  a 
frame  holding  the  suspended  wicks  are  placed  troughs  containing 
melted  tallow,  into  which  the  wicks  are  repeatedly  dipped.  After  each 
dipping  the  adherent  fat  is  allowed  to  cool  sufficiently  to  retain  a  fresh 
coating  on  immersion.  When  the  candles  have  thus  grown  to  the  proper 
thickness  they  are  left  to  cool  and  harden.  These  cheap  "dips  "  are, 
however,  now  being  replaced  by  small,  moulded  "composite  "  candles, 


76 


INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 


as  well  as  candles  made  from  the  softer,  paraffin  scale.  Pouring  is  used 
only  with  wax  candles,  which  cannot  be  moulded  because  of  the  adher- 
ing or  cracking  of  the  wax  in  removing  it  from  the  moulds.  A  well- 
made  wax  candle  should  show  rings  like  a  tree,  where  the  different 
layers  have  been  superposed.  By  far  the  greater  number  of  candles  are 
moulded,  by  which  process  they  acquire  a  much  more  finished  appear- 
ance. A  form  of  frame  in  common  use  is  represented  in  Fig.  28. 

The  materials  in  general  use  for  candle-making  are  tallow,  palmitic 
and  stearic  acids,  paraffin,  ozokerite  or  ceresine,  spermaceti,  and  beeswax. 

FIG.  28. 


Very  generally,  several  of  these  materials  are  admixed.  Stearic  candles 
have  a  small  quantity  of  paraffin  added  to  obviate  the  crystalline  struc- 
ture of  the  stearic  acid;  paraffin  candles  always  have  five  to  ten  per 
cent,  of  stearic  acid  in  them,  to  prevent  the  softening  and  bending  of 
the  paraffin  when  warmed.  Spermaceti  and  beeswax  are  more  expensive 
than  the  other  materials,  and  are  only  used  now  for  special  purposes, 
as  for  church-candles  and  carriage-lights.  Ozokerite  gives  the  paraffin 
candle  of  highest  fusing  point,  being  some  six  degrees  higher  than  any 
other  variety  of  paraffin.  Colored  paraffin  candles  are  made  by  dis- 
solving the  coloring  matter  (vegetable  or  aniline  dyes,  not  mineral 
colors)  in  stearic  acid,  and  then  mixing  this  with  the  paraffin,  which 
itself  does  not  take  up  the  color.  Paraffin  and  other  transparent  candles 
must  be  filled  in  the  mould  very  hot,  and  after  all  air-bubbles  have 
escaped,  the  moulds  must  be  rapidly  cooled  by  a  large  flush  of  cold  water 


PROCESSES  OF  TREATMENT. 


77 


to  prevent  the  paraffin,  etc.,  from  crystallizing  and  thus  causing  opacity. 
Of  interest  in  this  connection  is  the  table  of  illuminating  equivalents, 
or  quantities  of  different  illuminating  materials  necessary  to  produce 
the  same  amount  of  light,  prepared  by  Frankland. 


Young's   paraffin   oil 1.00  gallon. 

American  petroleum,  No.  1 .  1.26  gallons. 
American  petroleum,  No.  2.  1.30  gallons. 
Paraffin  candles  18.60  pounds. 


Sperm  candles    22.90  pounds. 

Wax  candles 26.40  pounds. 

Composite   ( stearine )    29.50  pounds. 

Tallow    36.00  pounds. 


4.  OLEOMARGARINE,  OR  ARTIFICIAL  BUTTER  MANUFACTURE. — The  man- 
ufacture of  a  butter-substitute  from  the  solution  of  palmitin  in  olein, 
which  is  known  as  oleomargarine,  is  a  fat  industry,  but,  because  of  its 
close  relations  to  natural  butter  made  from  cows'  milk,  it  will  be  con- 
sidered as  supplementary  to  the  description  of  butter  under  milk  indus- 
tries.    (See  p.  284.) 

5.  GLYCERINE  MANUFACTURE. — For  many  years  after  the  develop- 
ment of  the  soap  and  candle  industries,  no  attempt  was  made  to  recover 
the  glycerine  which  was  liberated  in  the  saponification.     Its  applica- 
tions in  medicine  and  for  technical  purposes  have  made  it  important 
to  extract  and  purify  it,  however,  and  it  has  now  assumed  almost  equal 
importance  with  the  other  fat  constituents.    The  two  methods  of  saponi- 
fication, by  which  glycerine  has  been  obtained  on  a  large  scale,  are  the 
process  of  Wilson  &  Payne,  of  decomposing  the  fats  by  superheated 
steam  and  after  distillation  (see  p.  65),  and  the  lime  autoclave  process 
of  Milly.     (See  p.  64.)     In  the  distillation  process,  however,  by  suitable 
arrangement  for  fractional  condensation,  it  is  found  possible  to  con- 
centrate the  aqueous  glycerine  in  the  process  of  distillation.    Care  must 
be  taken  that  the  temperature  of  600°  F.  (315°  C.)  is  not  exceeded,  and 
that  plenty  of  steam  is  present,   otherwise  some  glycerine  is   decom- 
posed and  acrolein  is  formed.     In  the  Milly  process,  after  the  decom- 
position of  the  fat  is  completed  in  the  autoclave,  the  contents  are  blown 
out  into  a  tank  and  the  "sweet  water  "   (glycerine)   is  run  off.     The 
concentrating  may  be  done  in  contact  with  air  or  preferably  it  may  be 
wrorked  in  some  form  of  vacuum  evaporator.     Evaporation  is  continued 
to  26°  B.  (1.220  specific  gravity),  when  the  glycerine  is  of  a  brownish 
color,  and  is  known  as  "raw,"  in  which  state  it  is  sold  for  many  pur- 
poses, and  contains  about  ninety  per  cent,  of  glycerine  and  traces  only 
of  mineral  impurities.    At  Price's  Candle  Company's  works  the  further 
purification  is  conducted  as  follows.    The  raw  glycerine,  specific  gravity 
1.240  to  1.245,  is  heated  in  a  jacketed  pan  with  that  kind  of  animal 
charcoal  known  as  ivory-black,  and  is  then  distilled ;  this  alternate  treat- 
ment is  repeated  as  often  as  is  necessary.    The  distillation  is  performed 
with  superheated  steam  in  a  copper  still  provided  with  copper  fractional 
condensers,  the  still  being  also  heated  externally;  the  operation  is  per- 
formed at  as  low  a  temperature  as  is  consistent  with  distillation,  usually 
about  440°  F.  (227°  C.). 

It  is  obvious  that  in  soap-making,  as  enormous  quantities  of  the  fats 
are  decomposed,  corresponding  quantities  of  glycerine  go  into  the  spent 


78  INDUSTRY  OF   THE  FATS  AND  FATTY  OILS. 

lyes.  It  is  only  very  recently  that  it  has  been  attempted  to  recover  this 
glycerine.  The  two  processes  at  present  in  use  are  those  of  Jobbins  and 
Van  Ruymbeke  and  of  Garrigues.  Another  suggestion  of  more  recent 
date  is  to  deglycerinize  all  fats  before  saponifying  them.  The  process 
of  Michaud  Freres,  of  Paris,  as  carried  out  by  the  Continental  Gly- 
cerine Company,  of  New  York,  realizes  this  idea  very  successfully. 

According  to  their  patent  ''the  fatty  matter  is  subjected  in  a  close 
vessel  to  the  action  of  the  steam,  at  a  pressure  of  one  hundred  to  one 
hundred  and  thirty  pounds  per  square  inch,  and  at  corresponding  tem- 
perature in  presence  of  one-fourth  to  one-third  part  of  its  weight  of  water 
and  one-fifth  to  three-fifths  per  cent,  of  its  weight  of  the  oxide  of  zinc, 
known  commercially  as  zinc  white,  or  a  like  proportion  of  zinc  powder 
or  zinc  gray,  which  is  a  residue  in  the  treatment  of  zinc,  being  a  mixture 
of  zinc  with  its  oxide.  .  .  The  very  small  proportion  of  mineral  sub- 
stance used  is  sufficient  for  dispensing  with  the  acid  treatment  applied 
for  decomposing  lime  soap,  and  the  product  obtained,  consisting  almost 
exclusively  of  acid  fat,  can  be  converted  by  the  acids  usually  employed 
into  soap  or  candles.  In  soap-making,  the  dissolving  powers  of  the 
caustic  alkalies  remove  all  objections  to  the  presence  of  the  zinc  if  it 
should  be  used  in  excess.  The  reducing  power  of  the  zinc  powder  pre- 
vents discoloration  of  the  acid  fats  such  as  results  from  the  ordinary 
treatment."  The  glycerine  thus  produced  finds  a  ready  sale,  as  it  runs 
from  the  evaporators,  and  from  it,  as  "crude,"  ninety-six  per  cent,  of 
pure  glycerine  can  be  obtained. 

5a.  NITRO-GLYCERINE  AND  DYNAMITE. — In  1847  Sobrero  discovered 
a  very  interesting  derivative  of  glycerine,  and  in  1862  A.  Nobel  gave 
it  to  the  world  as  a  technical  product  of  the  greatest  importance.  When 
strong  glycerine  is  gradually  added  to  a  well-cooled  mixture  of  very 
strong  nitric  and  sulphuric  acids,  it  is  converted  into  glyceryl  nitrate, 
or  nitro-glycerine.  For  the  manufacture  of  nitro-glycerine  on  a  large 
scale,  Nobel  recommends  that  one  part  of  good  glycerine  be  allowed  to 
flow  in  a  thin  stream  into  a  well-cooled  mixture  of  four  parts  of  concen- 
trated sulphuric  acid  and  one  part  of  the  very  strongest  nitric  acid  (1.52 
specific  gravity),  the  mixture  being  contained  in  a  wooden  vessel  lined 
with  lead.  -  Means  should  be  provided  by  which  the  mixture  can  at 
once  be  run  into  a  large  quantity  of  water  should  the  action  threaten 
to  become  too  violent.  On  standing,  the  nitro-glycerine  separates  as  a 
layer  on  the  surface  of  the  acid,  and  is  skimmed  off  and  washed  with 
water  and  solution  of  sodium  carbonate  to  get  rid  of  every  trace  of  free 
acid.  Or,  according  to  the  same  authority,  a  mixture  is  made  of  one  part 
nitre  with  3.5  parts  of  sulphuric  acid  (1.83  specific  gravity),  the  mix- 
ture cooled  to  32°  F.  (0°  C.),  and  the  liquid  poured  off  from  the  acid 
potassium  sulphate,  which  separates  out;  into  this  liquid  the  glycerine 
is  slowly  dropped,  the  mixture  poured  into  water,  and  the  separated 
nitre-glycerine  washed  thoroughly  and  dried.  The  yield  is  two  hundred 
and  twenty-three  per  cent,  of  the  glycerine  used. 

It  has  been  suggested  to  mix  the  glycerine  beforehand  with  the  sul- 
phuric acid,  and  then  run  this  mixture  into  the  nitric  acid,  and  it  is 


PRODUCTS. 


79 


claimed  that  the  elevation  of  temperature  is  less  than  when  the  ordi- 
nary method  is  followed ;  but  the  process  does  not  seem  to  have  been 
satisfactory  in  practice  when  tried  in  England. 

When  absorbed  by  infusorial  earth,  "  kieselguhr, "  sawdust,  mica 
powder,  or  other  inert  porous  material,  nitro-glycerine  forms  the  dif- 
ferent varieties  of  dynamite,  and,  when  combined  with  gun-cotton,  it 
constitutes  the  explosive  known  as  "blasting  gelatine." 


m.  Products. 

1.  PURIFIED  OILS,  FATS,  AND  WAXES,  AND  PRODUCTS  FROM  THE  SAME. 
— Most  of  the  important  oils,  fats,  and  waxes  have  already  been  described 
as  raw  materials,  and  the  methods  of  purifying  them  have  been  noted. 
The  purified  oils  are  in  some  cases  the  final  products  sought,  and,  in 
some  cases,  only  improved  raw  materials  for  the  main  industries,  like 
soap-making,  candle-making,  and  glycerine  extraction.  These  purified 
oils  having,  therefore,  been  referred  to  as  raw  materials,  will  not  be 
further  noted.  A  number  of  side-products,  obtained  with  or  produced 
from  these  oils,  remain  to  be  mentioned. 

One  of  these  minor  products  of  great  value  is  the  oil-cake,  or  com- 
pacted mass  of  crushed  seeds  or  nuts,  from  which  the  oil  has  been 
expressed  or  extracted.  This  contains  all  of  the  woody  fibre  and  mineral 
matter  of  the  seed  or  nut,  the  residue  of  oil  or  fatty  matter  not  ex- 
tracted, and,  what  gives  it  special  value,  the  proteids  or  nitrogenous 
constituents.  The  oil-cake  thus  becomes  a  most  valuable  cattle  food  and 
a  basis  for  artificial  fertilizers.  The  following  table  gives  the  compo- 
sition of  a  number  of  the  most  important  oil-cakes: 


Water. 

Fat. 

Non-rutrogen- 
ous  materials. 
Woody  fibre. 

Ash. 

.Protein 
material. 

Nitrogen. 
per  cent. 

Earth-nut  cake 

11.50 

8.80 

31.10 

7.25 

41.35 

6.80 

Cotton-seed  cake 

13.00 

7.50 

51.00 

850 

2000 

2.90 

Kape-oil  cake    . 

10.12 

9.23 

41.93 

6.48 

31.88 

6.00 

Colza-oil  cake  . 

11.35 

9.00 

42.82 

6.28 

30.55 

4.50 

Sesame-oil  cake 

10.35 

10.10 

38.80 

9.80 

31.93 

5.00 

Beech-nut  cake 

11.40 

8.50 

49.80 

5.30 

24.00 

3.20 

Linseed  cake     . 

10.56 

9.83 

44.61 

6.50 

28.50 

4.25 

Camelina  cake  . 

9.60 

9.20 

50.90 

7.00 

23.30 

3.60 

Poppy-oil  cake 

9.50 

890 

37.67 

11.43 

32.50 

6.00 

Sunflower-oil  cake 

10.20 

8.50 

48.90 

11.40 

21.00 

2.40 

Hempseed  cake 

10.00 

8.26 

48.00 

12.24 

21.60 

3.30 

Palm-nut  cake  . 

9.50 

8.43 

40.95 

10.62 

30.40 

4.50 

Cocoa-nut  cake 

10.00 

9.20 

40.50 

10.50 

30.00 

4.50 

It  will  be  seen  in  this  table  that  they  vary  in  proteids  or  flesh-forming 
constituents  quite  widely.  All  of  these  cakes,  however,  are  too  rich  in 
these  proteids  and  in  fats  to  be  used  unmixed  as  fodder.  They  are,  in 
practice,  mixed  with  cereals,  hay,  and  straw,  and  then  constitute  a  valu- 
able food.  The  ash  is,  moreover,  very  rich  in  phosphoric  acid  and  in 
potash,  and  this  explains  its  value  for  fertilizer  manufacture. 


80  INDUSTRY  OF   THE  FATS  AND  FATTY  OILS. 

Thus  it  is  stated  that,  as  a  fertilizer,  one  ton  of  cotton-seed-hull  ashes 
has  as  much  value  as  four  and  one-half  of  average  hard-wood  ashes,  or 
fifteen  of  leached  hard-wood  ashes. 

The  amount  of  oil-cake  obtained  from  the  expression  of  the  different 
vegetable  oils  is  enormous.  Thus  it  is  stated  that  one  short  ton  of  cotton- 
seed (constituting  forty  per  cent,  of  the  raw  cotton)  will  yield  eight 
hundred  pounds  of  cotton-seed  cake  and  forty-five  gallons  of  crude 
cotton-seed  oil.  The  amount  of  crude  cotton-seed  annually  obtained  in 
the  United  States  is  estimated  at  four  thousand  million  pounds,  half  of 
which  only  is  required  for  sowing. 

The  accompanying  table,  prepared  by  Grimshaw,  will  show  how 
thoroughly  the  cotton-seed  is  now  utilized: 

Cotton-seed,  2000  pounds. 


Cattle 
food. 


Meats 

,  1089  pounds.          Lint,  20  pounds.            Hulls, 

i 

891  pounds. 

Cake, 
800  pounds. 

Meal. 

Crude  oil, 
289  pounds. 

i 

Fibre. 

High-grade 
paper. 

Bran. 

i  — 

Fuel. 
Ashes. 
Fertilizer. 

Summer                     Soap  stock, 
yellow. 

i 

do  1  nil     ml 

Soap. 

Summer  white— 

T  nrrl 

Winter        Cotton-seed 
yellow.         stearine. 

An  important  manufactured  oil  is  what  is  known  as  "Turkey-red 
oil,"  used  in  the  process  of  alizarin  dyeing.  (See  p.  539.)  There  are, 
in  fact,  two  entirely  distinct  oils  known  under  this  name.  One  is 
simply  an  inferior  grade  of  olive  oil,  that  known  as  ' '  Gallipoli  oil, ' '  and 
for  this  particular  use  is  prepared  from  somewhat  unripe  olives,  which 
are  steeped  for  some  time  in  boiling  water  before  being  pressed.  This 
treatment  causes  the  oil  to  contain  a  large  proportion  of  extractive 
matter,  and  hence  it  soon  becomes  rancid.  This  preparation  has  long 
been  used  in  the  old  process  of  Turkey-red  dyeing,  under  the  name  huile 
tournante.  The  other,  used  for  producing  alizarin  reds  by  the  quick 
process,  is  the  ammonium  salt  of  sulpho-ricinoleic  acid  (C18H33 
(HS03)03),  a  body  which  is  obtained  mixed  with  unaltered  glycerides 
and  with  products  of  its  decomposition  by  the  action  of  sulphuric  acid 
upon  castor  oil. 

From  linseed  oil,  as  the  most  important  of  the  class  of  drying  oils, 
is  prepared  a  product  of  great  value  for  paint  and  varnish  manufacture. 
(See  p.  112.)  What  is  called  "boiled  oil"  is  linseed  oil,  which  has  been 
heated  to  a  high  temperature  (130°  C.  and  upward),  while  a  current  of 
air  is  passed  through  or  over  the  oil,  and  the  temperature  increased 
until  the  oil  begins  to  effervesce  from  evolution  of  products  of  decom- 
position. By  adding  litharge,  red-lead,  ferric  c^xide,  or  manganese  di- 
oxide, or  hydrate,  during  the  process  of  boiling,  the  oxidation  and  con- 
sequent drying  of  the  product  are  still  further  facilitated.  The  nature, 
proportion,  and  mode  of  adding  these  substances  are  usually  kept 


PRODUCTS. 


81 


jealously  secret.  Lead  acetate  and  manganous  borate  are  among  the 
most  approved.  The  action  of  some,  at  least,  of  these  "dryers  "  (e.  g., 
compounds  of  manganese)  seems  to  be  that  of  carriers  of  oxygen,  while 
litharge  dissolves  in  the  oil  and  acts  partly  as  a  carrier  of  oxygen  and 
partly  as  the  base  of  certain  salts  which  oxidize  very  rapidly. 

Many  of  the  fatty  oils  and  notably  some  of  the  non-drying  oils  are 
capable  of  being  thickened  and  increased,  especially  in  specific  gravity 
and  viscosity,  by  having  a  stream  of  air  blown  through  them.  The  prod- 
ucts of  this  treatment  are  known  as  blown  oils  or  oxidized  oils.  They 
are  not  resinified  as  when  the  drying  oils  are  boiled  with  driers,  but 
become  thick  and  viscid  like  castor  oil.  This  property  is  taken  advan- 
tage of,  therefore,  in  the  production  of  heavy  viscid  products,  which 
are  used  in  admixture  with  mineral  oils  for  the  purpose  of  preparing 
lubricants  for  heavy  machinery.  While  cotton-seed,  rape,  olive,  earth- 
nut,  lard,  and  linseed  oils  have  all  been  utilized  in  this  way,  the  two 
most  commonly  employed  are  rape  and  cotton-seed  oils. 

In  carrying  out  the  blowing  operation,  the  oil  is  usually  heated  to 
70°  C.  (138°  F.)  or  slightly  more,  and  air  is  then  blown  in  through 
a  vertical  pipe  which  passes  down  nearly  to  the  bottom  of  the  kettle, 
the  air  being  itself  heated  to  the  same  temperature.  In  a  short  time  the 
oil  begins  to  oxidize  and  the  temperature  to  rise.  The  steam  is  then 
shut  off  from  the  heating  coils,  and  care  must  now  be  taken  that  the 
temperature  does  not  rise  above  80°  C.  (176°  F.).  The  process  usually 
lasts  from  twelve  to  forty-eight  hours,  according  to  the  nature  of  the  oil 
being  treated  and  the  character  of  the  product  desired.  By  continuing 
the  operation,  products  may  be  obtained  of  specific  gravity  as  high  as 
from  .985  to  .999  even. 

Blown  oils  vary  in  color  from  a  clear  yellow  to  a  dark  reddish  yellow, 
and  have  a  peculiar  and  somewhat  disagreeable  odor.  They  are  very 
viscous,  as  dense  or  denser  than  castor  oil,  from  which  they  differ  in  not 
being  readily  soluble  in  alcohol  but  in  being  soluble  in  petroleum  spirit. 
Their  perfect  miscibility  with  heavy  mineral  oils  is,  however,  their 
chief  advantage.  The  percentage  of  free  fatty  acids  is  usually  increased 
by  the  blowing  operation  and  the  percentage  of  insoluble  fatty  acids 
decreased,  owing  to  the  formation  of  soluble  oxyacids. 

The  following  table  from  Lewkowitsch  ("Oils,  Fats,  and  Waxes," 
2d  ed.,  p.  734)  will  show  the  change  undergone  by  rape  oil  in  conse- 
quence of  the  blowing  operation: 


Specific 
gravity 
at  15.5°  C. 

Free  acid 
as  oleic. 

Saponifi- 
cation 
value. 

Iodine 
value. 

Insoluble 
acids. 

Soluble 
acids. 

Rape  oil     

0.9141 

6.10 

173.9 

100.5 

94.76 

0.52 

Same,  5  hours'  blowing  . 

0.9275 

5.01 

183 

88.4 

Same,  20  hours'  blowing 

0.9615 

7.09 

194.9 

63.2 

85.94 

10.02 

2.  SOAPS. — In  noting  the  processes  for  practical  soap-making,  the 
following  classes  of  soaps  were  indicated:  (1)  compact  soaps,  including 
(a)  curd  soaps;  (6)  mottled  soaps,  and  (c)  yellow  soaps;  (2)  smooth 

6 


82 


INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 


or  cut  soaps;  (3)  filled  or  padded  soaps;  and  (4)  soft  or  potash  soaps. 

The  most  important  difference  between  the  compact,  cut,  and  filled 
soaps  is  the  amount  of  water  present  in  the  soap.  In  the  compact  soap 
it  may  vary  from  ten  to  twenty-five  per  cent.,  in  the  cut  soap  from 
twenty-five  to  forty-five  per  cent.,  and  in  the  filled  soap  from  forty-five 
to  seventy-five  per  cent.  In  addition,  the  filled  soap  contains  the  gly- 
cerine, spent  lye,  and  other  impurities  of  the  soap  copper. 

The  following  table  of  analysis,  by  Mr.  C.  Hope,  as  quoted  by  Allen,* 
will  illustrate  the  composition  of  a  variety  of  soaps  belonging  to  these 
several  classes: 


NAME  OP  SOAP. 

MATERIALS.  • 

Fatty  and  resin  an- 
hydrides. 

§ 

y 

to 

'3 
o> 

d 

cj  oj 

S° 

1 

cw 

1 

B 

i 

03 

•g 
CO 

Sodium  carbonate 
and  hydrate. 

Neutral  salts,  lime, 
and  iron  oxide. 

ij 

I 
3 

* 

"3 
g 

White  No  1  

Tallow  
Tallow  and  cocoa-nut  oil  .  . 
Tallow  and  cocoa-nut  oil  .  . 
Tallow  and  cocoa-nut  oil  .  . 
Tallow,  rosin,  and  cotton- 
seed oil    

69.06 
60.50 
55.71 
44.27 

71.30 

49.95 
71.20 
62.66 
59.28 
38.89 
59.92 
42.41 
60.69 
48.20 
39.92 
63.06 
10.90 
19.42 

8.98 
6.82 
6.90 
6.23 

7.98 

7.00 
7.58 
7.27 
6.65 
5.76 
6.76 
4.14 
7.22 
5.00 
4.70 
7.25 
1.36 
3.11 

.01 

.06 
.03 
7.02 

1.07 

2.34 
.06 
.06 
.42 
6.40 
.02 
5.64 
.04 
.42 
.62 
.02 
.03 
9.00 

2.36 
.48 

1.01 
.03 
.03 
.01 
1.29 

l'.59 

'.18 
.25 

3.98 

.27 
.06 
.92 
.75 

.75 

.33 
.22 
.77 
.39 
1.62 
.92 
2.76 
.10 
.15 
.20 
.10 
Trace 
3.00 

.72 
.39 
.26 
1.00 

.82 

1.01 
1.03 
1.22 
.76 
2.53 
1.70 
.51 
.60 
.90 
1.81 
1.90 
3.27 
5.64 

21.14 
32.20 
36.54 
38.14 

17.44 

38.18 
19.70 
28.20 
32.35 
38.70 
31.30 
42.88 
31.22 
45.00 
52.40 
27.47 
84.00 
53.32 

100.18 
100.03 
100.36 
99.77 

99.84 

99.82 
99.82 
100.21 
99.86 
95.19 
99.75 
99.93 
100.00 
99.80 
99.90 
100.00 
99.56 
97.47 

White  No  2  

White  No  3         

White  No  4      

Cold  water  No.  1  

Tallow,  rosin,  and  cotton- 
seed oil  .             

Olive  oil,  No.  1  
Marseilles  No  1  

Olive  oil  
Chiefly  olive  oil   
Palm  oil    

Palm  oil,  No.  1  

Mottled    

Palm-nut  oil  

Satinet  

Tallow  and  rosin 
Tallow  and  rosin 
Tallow  and  rosin 
Tallow  and  rosin 
Tallow  and  rosin 
Not  mentioned  . 
Not  mentioned  . 
Palm-nut  oil  .  . 

Glasgow  almond  

Pale  rosin,  No.  2    

Pale  rosin,  No.  3    

Milling    

Yellow  (for  foreign  markets) 
Marine  (for  emigrants)    .  . 

Two  of  these  samples,  those  designated  as  "mottled  "  and  "marine," 
were  prepared  by  the  "cold  process  "  (see  p.  70),  which  accounts  for  the 
totals  being  appreciably  less  than  100.00,  as  the  glycerine  was  retained 
in  the  soap. 

The  chief  soaps  of  pharmacy,  as  analyzed  by  M.  Dechan,f  are  com- 
posed as  follows: 


"3 

<a 

5 

oj 

j3 

S 

•*-r 

to 

DESCRIPTION  OF  SOAP. 

8 

• 
a 

i 
j9 

ii 

0 

2 

s| 

bt 

~'~ 

as 

ai 

43  rt 

^ 

i-. 

3  O 

"3 

|8 

• 
E 

o 

90 

sS 

3 

S"3 

h 

fi 

03 

CO 

M 

* 

1-1 

Hard  soap  (sapo  durus}  .    .    . 
White  Castile  soap  (s.  Cast.  alb.  ) 
Mottled  Castile  soap    .... 

81.5 

76.7 
68.1 

9.92 
9.14 
8.9 

.08 
.09 
.19 

.00 
.00 
.15 

.28 
.36 
.63 

0.20 
0.90 
0.80 

10.65 
13.25 
21.70 

0.50 

O.GO 
1.30 

Tallow  soap  (sapo  animalis)  . 

78.3 

9.57 

.28 

.00 

.47 

0.40 

12.50 

1.10 

Soft  soap  (sapo  mollis)     .    .    . 

48.5 

12.6 

.38 

.17- 

.93 

1.00 

39.50 

1.60 

*  Allen,  Commercial  Organic  Analysis,  2d  ed.,  vol.  ii,  p.  272. 
t  Pharmaceutical  Journal  [3],  xv,  p.  870. 


PRODUCTS.  83 

Toilet  soaps  do  not  differ  in  essential  composition  from  the  best  of 
compact  and  cut  soaps,  as  given  above,  but  they  are  perfumed  and  given 
small  additions  of  cosmetic  or  hygienic  preparations.  They  are  pre- 
pared in  one  of  three  ways:  (1),  by  a  melting  of  plain  soaps;  (2),  a 
cold  perfuming  and  pressing  of  finely-divided  plain  soaps;  and  (3) 
direct  preparation  from  the  raw  soap-making  materials. 

Transparent  soaps  are  obtained  by  dissolving  the  soaps  in  alcohol 
and  drying  the  solution  in  moulds, — a  slow  process.  (See  also  p.  72.) 

Glycerine  soaps  are  obtained  by  dissolving  the  soaps  in  glycerine  by 
the  aid  of  heat.  Thy  glycerine  imparts  a  strength  to  the  lather. 

3.  CANDLES. — The  candle-making  materials  have  already  been  enu- 
merated.    (See  p.  74.)     Tallow  and  wax  candles  were  the  earliest  in  use. 
Stearine  candles,  known  also  under  the  name  of  Milly  candles,  from  the 
French  inventor  of  several  of  the  processes  of  saponification,  came  into 
use  in  1831.     About  the  same  time  paraffin,  first  obtained  in  quantity 
from  bituminous  shales,  and  later  from  ozokerite  and  petroleum,  was 
used  for  candle-making.     These  are  also  known  under  the  name  of 
"Belmontin  candles,"  from  the  locality  of  the  J.  C.  &  J.  Field  candle- 
works,  in  London.     Candles  of  mixed  stearic  acid  and  paraffin,  under 
the  name  of  Stella  or  Apollo  candles,  were  then  manufactured.     The 
Galician  ozokerite  is  also  purified  by  sulphuric  acid,  and  under  the 
name  of  ceresine  (see  p. -35)  is  used  in  Austria  for  candle  manufacture. 
Beeswax  and  spermaceti,  as  before  stated,   are  high-priced  materials, 
and  are  used  for  special  classes  of  candles.     The  paraffin  and  stearine 
candles  and  those  which  are  mixtures  of  these  materials  are  now  most 
generally  in  use. 

4.  OLEOMARGARINE  OR  BUTTERINE.     (See  p.  289.) 

5.  GLYCERINE     AND     NITRO-GLYCERINE. — The     chemical     compound 
which  is  liberated  along  with  the  fatty  acids  when  the  fats  are  saponified 
by  any  of  the  various  processes  already  narrated  is  a  triatomic  alcohol, 
called  glycerine.     When  purified  and  made  absolute,  it  is  a  colorless, 
viscid  liquid,  without  odor,  but  with  a  pronounced  sweet  taste.     The 
specific  gravity  of  the  absolute  glycerine  is  about  1.266  at  15°  C.    When 
kept  for  a  long  time  at  0°  C.,  rhombic  crystals  are  formed,  their  pro- 
duction being  greatly  facilitated  by  the  presence  of  a  ready-formed 
crystal.     The  crystals  are  hard  and  gritty,  but  deliquescent.     It  boils 
under  ordinary  pressure  at  290°  C.,  not  without  decomposition.     It  is 
highly  hygroscopic,  and  is  miscible  with  water  in  all  proportions.    Gly- 
cerine is  miscible  with  alcohol  in  all  proportions,  but  is  insoluble  in  chlo- 
roform,   benzene,    petroleum    spirit,    carbon    disulphide,    or   fixed    oils. 
Glycerine  is  nearly  insoluble  in  ether,   from  which  it  separates  any 
alcohol  or  water.    When  glycerine  is  heated  with  a  dehydrating  agent 
(e.  g.,  concentrated  sulphuric  acid),  irritating  fumes  of  acrolein  (acrylic 
aldehyde),  C3H3OH,  are  evolved,  smelling  of  burning  fat.    By  far  the 
largest  application  of  glycerine  is  for  the  manufacture  of  nitro-glycerine, 
but  it  is  also  employed  extensively  in  the  manufacture  of  toilet  soaps, 
for  filling  gas-meters  and  tubes  in  situations  liable  to  be  exposed  to 
great  cold,  and  in  pharmacy  and  medicine.    It  is  also  used  for  the  pres- 


84  INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 

ervation  of  food  products,  and  for  the  treatment  (scheelizing)  of  wine, 
vinegar,  and  beer. 

Nitro-glycerme  is  a  heavy,  oily  liquid  of  1.600  specific  gravity  at 
15°  C.  The  commercial  preparation  is  usually  yellowish  to  brownish, 
although  the  pure  oil  is  colorless.  It  has  no  marked  odor,  but  is  sensibly 
volatile  at  ordinary  temperatures,  and  the  vapor  causes  a  violent  head- 
ache in  those  unaccustomed  to  it;  but  people  constantly  employed  in 
mixing  and  handling  dynamite  do  not  suffer  from  the  effects.  Nitro- 
glycerine has  recently  been  employed  in  medicine,  especially  for  the 
treatment  of  angina  pectoris.  Nitro-glycerine  is  not  readily  inflam- 
mable, and  when  ignited  commonly  burns  with  a  greenish  flame,  without 
explosion.  The  most  characteristic  property  of  nitro-glycerme,  and 
that  which  gives  it  by  far  its  most  important  application,  is  that  of 
exploding  with  extreme  violence  when  smartly  struck  or  compressed  or 
when  dropped  on  an  iron  plate  heated  to  257°  C.  The  presence  of  free 
acid  in  nitro-glycerine,  however,  makes  it  liable  to  spontaneous  decom- 
position and  explosion. 

Nitro-glycerine  is  easily  saponified  by  alcoholic  potash,  and  is  re- 
duced by  various  deoxidizing  agents. 

Nitro-glycerine  in  undiluted  state  is  only  exceptionally  used  now  for 
explosive  purposes,  as  in  "  torpedoing  "  oil-wells.  For  blasting  purposes 
it  is  mechanically  mixed  or  absorbed  in  some  finely  divided  solid  ma- 
terial. 

Thus,  Dynamite  No,  1  contains  seventy-five  per  cent,  of  nitro-gly- 
cerine mixed  with  twenty-five  per  cent,  of  infusorial  earth  or  kieselguhr. 
This  mixture  is  then  packed  in  cartridges  of  paraffined  paper,  constitut- 
ing the  "stick  "  of  dynamite. 

Mica  powder  consists  of  fine  mica  scales  in  which  about  fifty  per 
cent,  of  nitro-glycerine  is  absorbed. 

Next  in  order  come  explosives  in  which  with  the  nitro-glycerine  is 
combined  an  active  base,  either  a  nitrate  or  a  mixture  of  nitrate  and 
combustible  substance,  like  charcoal  or  sulphur.  The  best  known  are : 

Dynamite  No.  2  contains  forty  per  cent,  of  nitro-glycerine,  sodium 
nitrate  thirty-eight,  sulphur  six,  resin  eight,  and  kieselguhr  eight. 

Dynamite  No.  3  contains  nitro-glycerine  fifteen,  and  eighty-five  of  a 
mixture  of  sodium  nitrate,  coal,  and  sodium  carbonate. 

Vulcan  powder  contains  nitro-glycerine  thirty,  sodium  nitrate  fifty- 
two  and  five-tenths,  and  sulphur  and  charcoal  seventeen  and  five-tenths. 

Atlas  poivder  A  and  B  contains  respectively  seventy-five  and  fifty 
of  nitro-glycerine,  with  sodium  nitrate,  wood  fibre,  and  magnesium  car- 
bonate. 

Hercules  powder  is  similar  to  Atlas  powder  B,  but  contains  only 
forty  per  cent,  of  nitro-glycerine  and  forty-five  of  sodium  nitrate. 

Vigorite  contains,  with  thirty  of  nitro-glycerine,  potassium  chlorate 
forty-nine,  potassinm  nitrate  seven,  wood  pulp  nine,  magnesium  car- 
bonate and  moisture  five. 

Forcite  contains  nitro-glycerine  seventy-five,  potassium  nitrate 
eighteen,  and  gelatinized  cotton  seven.  This  latter  ingredient  is  made 


ANALYTICAL  TESTS  AND  METHODS.  85 

by  treating  finely  pulped  cotton  with  steam  under  pressure  until  con- 
verted into  a  jelly,  which  is  then  mixed  with  the  nitro-glycerine  and  the 
finely  powdered  nitrate  added.  The  resulting  product  is  a  plastic  mass 
resembling  rubber,  impervious  to  water,  and  relatively  safe  to  handle. 

Still  another  and  more  recently  developed  class  of  explosives  are 
those  in  which  nitro-cellulose  or  gun-cotton  is  combined  with  nitro- 
glycerine. The  most  important  are: 

Blasting  gelatine  or  gelatine  dynamite,  which  is  a  mixture  of  about 
eighty  parts  of  nitro-glycerine  with  twenty  of  nitro-cellulose.  Any 
unnitrated  cotton  or  trinitro-cellulose  interferes  with  the  solution  of 
the  nitro-glycerine.  The  addition  of  four  per  cent,  of  camphor  renders 
the  mixture  incapable  of  exploding  when  struck  by  a  rifle  bullet,  but  it 
can  be  detonated  by  a  strong  dynamite  cap. 

Cordite,  which  has  been  adopted  by  the  English  government  as  a 
standard  "smokeless  powder,"  contains  nitro-glycerine  fifty-eight,  gun- 
cotton  thirty-seven,  and  vaseline  five.  The  nitro-glycerine  and  gun- 
cotton  are  first  mixed,  19.2  parts  of  acetone  added,  and  the  pasty  mass 
kneaded  for  several  hours.  The  vaseline  is  then  added  and  the  mixture 
again  kneaded.  The  paste  is  then  forced  through  fine  openings  to  form 
threads,  which  are  dried  at  about  40°  C.  until  the  acetone  evaporates. 
The  threads  are  then  cut  into  short  lengths  for  use.  They  resemble  a 
brown  twine. 

There  are  analogous  explosives  known  as  "smokeless  powders  "  in 
which  no  nitro-glycerine  at  all  enters,  but  which  are  merely  cellulose 
nitrates  or  gun-cotton  gelatinized  and  dried,  as  just  described. 

Picrates  and  picric  acid  are  sometimes  used;  but,  while  powerful  ex- 
plosives, they  are  considered  too  unstable.  Melinite  and  Lyddite  are 
of  this  class. 

IV.    Analytical  Tests  and  Methods. 

1.  FOR  OILS  AND  FATS. — The  total  amount  of  oil  in  any  particular 
oil-seed  or  other  material  is  always  an  important  matter  to  determine. 
This  is  best  effected  by  treating  the  finely  divided  and  previously  dried 
substance  with  solvents  under  such  conditions  as  to  insure  complete  ex- 
traction. A  form  of  apparatus  in  which  this  can  be  effected  with  the 
minimum  amount  of  the  solvent  is  what  is  called  an  oleometer.  One  of 
the  best  of  these  is  the  Soxhlet  extractor,  shown  in  Fig.  29,  where  A 
represents  the  extractor,  B  the  distillation  flask,  C  the  condenser,  and 
D  the  siphon-tube  which  empties  the  extractor.  A  is  filled  to  three- 
fourths  its  capacity  with  the  powdered  oil  seed,  and  the  bulb  B  is  half 
filled  with  the  petroleum-ether,  carbon  disulphide,  or  proper  solvent. 
The  apparatus  is  then  connected,  as  shown  in  the  cut.  Filter  thimbles 
stamped  out  of  Swedish  filter  paper  are  largely  used  in  this  connection 
to  contain  the  weighed  substance.  They  slip  in  the  extractor  and  can  be 
weighed  before  and  after  the  extraction. 

To  recover  the  oil  from  its  solution  in  the  ether  or  other  liquid 
employed,  the  solvent  should  be  distilled  off  at  a  steam  heat,  and  the 


86 


INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 


last  traces  of  it  removed  by  placing  the  flask  on  its  side  and  heating  it 
in  the  water-oven  until  constant  in  weight. 

The  physical  constants  which  are  relied  upon  as  characteristic  in  the 
case  of  oils  and  fats  are  specific  gravity,  and  in  the  case  of  solid  fats, 
fusing  points.  Boiling-points  are  not  relied  upon,  because  of  the  partial 
decomposition  which  fixed  oils  usually  undergo  when  heated  to  high 
temperatures. 

Specific  gravity  in  the  case  of  the 
liquid  oils  may  be  determined  with  the 
aid  of  the  specific  gravity  bottle,  the 
Sprengel  tube,  or  the  Westphal  hydro- 
static balance.  The  first  of  these  is  so 
well  -known  from  elementary  works  on 
chemistry  as  to  need  no  description  here. 
The  Sprengel  tube  is  a  U-shaped  tube, 
of  which  the  two  ends  terminate  in  cap- 
illary tubes  bent  at  right  angles  to  the 
sides.  The  tube  is  completely  filled  with 
oil  by  immersing  the  open  end  of  the 
tube  in  the  liquid  and  gently  sucking 
the  air  out  from  the  other  orifice.  The 
U-tube  is  then  placed  in  the  mouth  of  a 
conical  flask,  containing  boiling  water 
(if  the  determination  is  to  be  made  at 
100°  C.)  or  water  at  any  other  fixed 
lower  temperature.  The  excess  of  oil 
that  escapes  at  the  orifices  of  the  tube 
is  wiped  off  with  soft  paper,  and  when 
the  expansion  ceases  the  tube  is  removed, 
wiped  dry,  allowed  to  cool,  and  weighed. 
The  calculation  can  then  be  made,  know- 
ing the  weight  of  the  tube  empty  and 
filled  with  water  at  the  same  tempera- 
ture, or  at  15°  C.  The  Westphal  bal- 
ance is  shown  in  Fig.  30.  The  ther- 
mometer or  other  plummet  used  dis- 
places a  definite  volume  of  the  oil,  so 

that  the  loss  in  weight  is  the  weight  of  this  bulk  of  the  oil  under  exami- 
nation. 

The  melting-point  of  solid  fats  may  be  gotten  with  considerable  accu- 
racy by  the  melting-point  method  in  general  use  in  chemical  laboratories. 
A  capillary  tube  is  filled  with  the  fat  while  it  is  in  the  melted  state. 
and  then,  after  allowing  it  to  cool  and  solidify,  attach  the  tube  to  the 
stem  of  a  delicate  thermometer  and  immerse  the  thermometer  in  a  beaker 
of  water,  which  is  then  gradually  heated  until  the  melting-point  of  the 
fat  is  reached,  and  it  liquefies  in  the  capillary  tube.  The  temperature  at 
which  this  takes  place  is  at  once  read  off  on  the  attached  thermometer. 


ANALYTICAL  TESTS  AND  METHODS. 


87 


To  insure  accuracy  it  is  desirable  to  immerse  the  beaker  of  water  in  an 
outer  vessel  also  filled  with  water,  to  which  the  heat  is  applied. 

The  solidifying  point  of  the  liberated  fatty  acids  in  the  case  of  the 
analysis  of  an  individual  fatty  oil  is  frequently  determined,  and  is 
known  as  "the  titer  test."  One  hundred  grammes  of  the  fat  under 
examination  are  saponified  (see  p.  88),  the  separated  fatty  acids  freed 
from  water  and  filtered  through  a  dry  plaited  filter  and  allowed  to 
solidify.  The  fatty  acid  mixture  is  then  carefully  melted  and  a  rather 
long  test-tube  filled  to  more  than  half  its  capacity.  The  tube  having 
been  fastened  by  means  of  a  cork  into  a  wide-mouthed  bottle,  a  delicate 
thermometer  indicating  one-tenth  of  a  degree  is  inserted  into  the  fatty 
acids  so  that  the  bulb  reaches  the  centre  of  the  mass.  When  a  few  crys- 
tals appear  at  the  bottom  of  the  tube  the  mass  is  stirred  by  giving  the 


FIG.  30. 


il     il     al    tfaTerTTri 


thermometer  a  rotary  movement,  first  to  the  right  and  then  to  the  left. 
The  mass  is  thus  stirred  without  allowing  the  thermometer  to  touch  the 
sides  of  the  tube  until  it  becomes  cloudy  throughout.  The  temperature 
will  fall  steadily  and  then  rise  suddenly  some  tenths  of  a  degree  and 
become  stationary  for  a  brief  period  of  time.  The  reading  taken  at 
this  moment  is  called  the  "titer  test  "  or  solidifying  point. 

Of  great  importance  with  some  of  the  fatty  oils,  such  as  sperm,  rape, 
and  lard  oils,  is  the  question  of  viscosity,  and  in  quite  a  number  the 


88 


INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 


question  of  cold  test.  The  methods  of  determining  these  have  been 
given  in  detail  under  mineral  oils.  (See  p.  43.) 

In  some  special  eases  the  use  of  the  oleo-refractometer,  an  instrument 
for  noting  the  difference  in  refractive  indices  of  oils,  has  proven  valuable. 
Thus,  true  butter  fat  can  be  distinguished  by  this  means  from  butterine 
or  oleomargarine. 

A  number  of  chemical  reactions  have  been  taken  at  one  time  or 
another  for  the  purpose  of  distinguishing  between  the  different  animal 
and  vegetable  oils  and  fats.  Many  are  unreliable  and  the  results  con- 
tradictory, because  dependent  upon  special  conditions,  so  that  no  great 
value  attaches  to  them.  This  statement  may  fairly  be  said  to  apply  to 
most  of  the  color-reactions  which  are  gotten  by  the  action  of  sulphuric 
and  nitric  acids  upon  the  different  oils  and  to  the  differences  in  eleva- 
tion of  temperature  caused  by  the  addition  of  concentrated  sulphuric 
acid  to  the  fatty  oils. 

Of  much  greater  value,  as  affording  general  reactions  for  the  distin- 
guishing of  the  different  oils  and  fats,  are  two  processes  of  treatment 
now  very  generally  adopted  by  chemists  in  the  analysis  of  fats  and  fatty 
oils, — viz.,  the  saponification  value  and  the  bromine  or  iodine  absorption 
value. 

The  saponification  value  (known  also  as  Kottstorfer  value)  indicates 
the  number  of  milligrammes  of  potassium  hydroxide  required  for  the  com- 
plete saponification  of  one  gramme  of  the  fat  or  wax.  The  determina- 
tion is  carried  out  as  follows :  About  1.5  to  2.5  grammes  of  the  fat  are 
treated  with  twenty-five  cubic  centimetres  of  one-half  normal  alcoholic 
potash;  when  saponification  has  taken  place,  one  cubic  centimetre  of  an 
alcoholic  solution  of  phenol-phthalein  is  added  and  the  liquid  titrated 
with  one-half  normal  hydrochloric  acid.  A  blank  experiment  is  then 
made  by  titrating  twenty-five  cubic  centimetres  of  the  alcoholic  potash 
alone,  and  the  difference  in  the  volumes  of  the  acid  used  gives  the 
volume  of  the  potash  solution  neutralized  by  the  fat,  which  is  then 
calculated  to  milligrammes  of  potash  for  one  gramme  of  fat  used.  The 
following  are  a  few  examples: 


OIL  OR  FAT. 

Milligrammes  of 
KOH  per  one  gramme 
of  fat.    Saponifica- 
tion equivalent. 

Average 
saturation- 
equivalent. 

Tallow  .                

193.2  to  198.0 

286.9 

192.0  to  196.5 

288.8 

246.2  to  268.4 

218.4 

220.0  to  247.  6 

240.8 

191.0  (average) 

293.7 

Cotton-seed  oil    

193.8  (average) 

289.4 

Rape  oil        

173.3  (average) 

323  7 

Linseed  oil        

191.3  (average) 

293.2 

221.5  to  232.4 

247.0 

Butterine  

193.5  to  196.5 

287.7 

123.4  to  147.4 

380  to  454 

128.9  (average) 

435.2 

Beeswax   .... 

94.5  (average) 

593.6 

ANALYTICAL  TESTS  AND  METHODS.  89 

The  numbers  in  the  last  column  designated  as  "saturation  equiva- 
lents "  represent  the  number  of  grammes  of  the  oil  or  fat  in  question 
that  would  be  decomposed  by  one  equivalent  of  potassium  hydroxide  in 
grammes,  and  is  obtained  by  dividing  the  percentages  of  potassium  hy- 
droxide required  into  5610,  which  is  the  molecular  weight  of  KOH  mul- 
tiplied by  100.  The  figures  given  as  "  saponification  equivalents  "  are 
most  generally  used  and  are  sufficiently  characteristic  to  allow  of  the 
recognition  of  adulteration  in  many  cases. 

The  bromine  and  iodine  absorption  methods  depend  upon  the  per- 
centage of  bromine  or  iodine  taken  up  by  the  oil  under  conditions  in- 
tended to  insure  the  formation  of  addition-compounds  only.  The  fatty 
acids  of  the  acetic  or  stearic  series  are  saturated  bodies,  which  do  not 
form  addition-compounds  with  bromine  or  iodine,  while  the  acids  of  the 
acrylic  or  oleic  series  combine  with  two  atoms  of  a  halogen  and  those 
of  the  propiolic  or  linoleie  series  with  four  atoms  of  a  halogen.  The 
glycerides  of  the  acids  of  these  three  series  behave  similarly  to  the  free 
acids,  so  that  the  determination  of  the  percentage  of  bromine  or  iodine 
assimilated  gives  a  measure  of  the  proportion  of  olein  as  against  pal- 
mitin  and  stearin  in  a  fat,  and  of  the  linolein  of  a  drying  oil  as  com- 
pared with  the  olein  of  a  non-drying  oil. 

Hiibl's  procedure  for  determining  the  iodine  absorption  is  as  follows: 

He  employs  an  alcoholic  solution  of  mixed  iodine  and  mercuric 
chloride:  twenty-five  grammes  of  iodine  are  dissolved  in  one-half  litre 
of  ninety-five  per  cent,  alcohol,  free  from  fusel  oil,  and  thirty  grammes 
of  mercuric  chloride  in  another  one-half  litre  of  the  same.  The  two 
solutions  are  then  mixed  after  filtration,  if  necessary,  and  used  after 
twelve  hours'  standing;  it  must  also  be  standardized  immediately  before 
or  after  use.  About  .2  to  .4  gramme  of  oils  or  .8  to  1  gramme  of  solid 
fats  is  weighed  off  and  dissolved  in  ten  cubic  centimetres  of  chloroform ; 
twenty  cubic  centimetres  of  iodine  solution  are  added,  and  successive 
additions  of  five  or  ten  cubic  centimetres  are  made  until,  after  two  hours, 
the  solution  has  a  dark  brown  tint.  It  is  best  to  leave  it  for  from  four 
to  six  hours  protected  from  the  light  before  the  next  step.  From  ten  to 
fifteen  cubic  centimetres  of  a  ten  per  cent,  aqueous  solution  of  potas- 
sium iodide  are  then  added  and  one  hundred  and  fifty  cubic  centi- 
metres of  water.  The  free  iodine  is  then  titrated  with  a  solution  of 
sodium  thiosulphate  containing  twenty-four  grammes  per  litre.  The 
amount  of  iodine  absorbed  is  calculated  into  units  per  cent,  of  the  fat, 
and  may  conveniently  be  termed  the  iodine  degree.  Since  one  cubic  cen- 
timetre of  the  thiosulphate  solution  is  equivalent  to  .0127  of  iodine,  the 
number  of  cubic  centimetres  of  this  sulphate  used  multiplied  by  12.7 
and  divided  by  the  weight  of  fat  used  will  give  the  iodine  figure  of  the 
fat  or  oil.  This  number  appears  to  be  tolerably  constant  for  each  oil, 
or  class  of  oils,  and  is  highest  with  the  vegetable  drying  oils,  as  will  be 
seen  by  this  short  list  taken  from  Hiibl's  table:  linseed  oil,  158;  hemp- 
seed  oil,  143 ;  cotton-seed  oil,  106 ;  olive  oil,  82.8 ;  lard,  59 ;  palm  oil,  51.5 ; 
tallow,  40;  cocoa-nut  oil,  8.9.  The  values  thus  obtained  are  quite  con- 
stant, provided  an  excess  of  iodine  of  not  less  than  thirty  per  cent,  be 


90  INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 

employed  and  the  operations  be  carried  out  under  exactly  the  same 
conditions. 

Wijs  proposes  a  solution  which  has  better  keeping  qualities  than  the 
Hubl  solution,  and  in  consequence  may  be  more  uniformly  depended 
upon  for  accurate  results.  He  dissolves  separately  9.4  grammes  of  iodine 
trichloride  and  7.2  grammes  of  iodine  on  the  water-bath  in  glacial  acetic 
acid,  taking  care  that  the  solutions  are  protected  from  absorbing  mois- 
ture while  solution  is  taking  place.  The  two  solutions  are  then  poured 
into  a  1000  cubic  centimetre  flask  and  the  contents  filled  to  the  neck 
with  glacial  acetic  acid.  The  chloroform  used  in  the  Hubl  process  is 
preferably  replaced  by  carbon  tetrachloride,  which,  however,  must  not 
contain  any  oxidizable  substances.  The  test  is  carried  out  as  with  the 
Hubl  solution,  but  the  time  for  standing  is  much  shorter. 

The  method  which,  however,  seems  simplest  and  shortest  is  that  of 
Hanus.  In  this  method  the  iodine  solution  is  prepared  by  dissolving 
13.2  grammes  of  pure  iodine  in  one  litre  of  pure  glacial  acetic  acid 
(ninety-nine  per  cent.),  and  to  the  cold  solution  add  three  cubic  centi- 
metres of  bromine  or  sufficient  to  practically  double  the  halogen  content 
when  titrated  against  the  thiosulphate  solution,  but  with  the  iodine 
slightly  in  excess.  The  thiosulphate  solution,  starch  paste  and  potas- 
sium iodide  solution  are  as  in  the  Hubl  method.  Proceed  as  in  the  Hubl 
method,  substituting  thirty  cubic  centimetres  of  the  Hanus  iodine  re- 
agent for  that  of  Hubl,  stirring  the  solution  before  adding  the  water, 
and  instead  of  adding  fifteen  or  twenty  cubic  centimetres  of  potassium 
iodine  use  only  ten  cubic  centimetres.  Only  half  an  hour  is  required  in 
this  case  for  the  full  action  of  the  iodine  on  the  oil,  instead  of  three 
hours  or  more. 

Certain  thermal  tests,  or  those  measuring  the  heat  of  reaction,  are 
used  in  some  cases.  The  Maumene  test  or  the  heat  developed  on  addi- 
tion of  strong  sulphuric  acid  has  long  been  known,  but  is  not  much 
relied  upon  at  present.  The  bromination  test  measures  the  rise  in  tem- 
perature caused  when  fats  absorb  bromine,  both  the  fat  and  the  bromine 
being  used  in  solution  in  chloroform  or  carbon  tetrachloride,  and  the 
vessel  in  which  the  reaction  is  carried  out  being  insulated  by  non-con- 
ducting packing.  The  results  bear  a  fixed  relation  to  the  iodine  absorp- 
tion number  and  one  can  be  calculated  approximately  from  the  other. 

For  qualitative  detection  only,  cotton-seed  oil  can  also  be  identified 
in  lard  by  Becchi's  test,  with  an  alcoholic  solution  of  silver  nitrate,  which 
gives  a  maroon  color  in  the  presence  of  the  cotton-seed  oil,  or  still  more 
certainly  by  Halphen's  test,  using  a  mixture  of  equal  volumes  of  amyl 
alcohol  and  carbon  disulphide  containing  about  one  per  cent,  of  sulphur 
in  solution  and  heating  to  boiling  with  this  reagent. 

The  adulteration  of  the  fatty  oils  very  frequently  calls  for  careful 
chemical  investigation.  The  presence  of  soap,  free  fatty  acids,  etc.,  in 
them  is  of  minor  importance;  the  first,  readily" removable  by  washing 
with  water  after  dissolving  the  oil-sample  in  carbon  disulphide,  and  the 
second  hardly  to  be  called  an  adulteration,  as  free  fat  acids  are  nor- 
mally present  in  many  vegetable  oils.  The  question  as  to  whether  they 


ANALYTICAL  TESTS  AND  METHODS.  91 

are  present  may  be  settled  by  Jacobsen's  method  of  adding  a  little 
rosaniline  to  the  oil.  If  free  fatty  acids  are  present,  the  oil  turns  red 
in  color  in  consequence  of  the  formation  of  rosaniline  oleate.  More  im- 
portant is  the  adulteration  with  resin  and  with  hydrocarbon  oils.  In 
the  absence  of  free  fatty  acids,  resin  may  be  isolated  from  fixed  oils  by 
agitating  the  sample  with  moderately-strong  alcohol,  separating  the 
spirituous  solution  and  evaporating  it  to  dryness.  The  separation  of 
the  resin  acids  from  free  fatty  acids  is  best  effected  by  Twitchell's 
method,  which  is  based  upon  the  fact  that  the  fatty  acids  are  converted 
into  ethyl  esters  when  acted  upon  by  hydrochloric  acid  gas  in  their 
alcoholic  solution,  whereas  colophony  resin  undergoes  little  or  no 
change,  abietic  acid  separating  from  the  solution.  For  details,  see 
Allen,  Com.  Org.  Anal.,  4th  ed.,  ii.  p.  77.  Hydrocarbon  oils  may  generally 
be  determined  by  saponifying  the  sample  with  alcoholic  potash  (five 
grammes  oil,  two  grammes  caustic  potash,  and  twenty-five  cubic  centi- 
metres ninety  per  cent,  alcohol).  The  soap  so  obtained  is  mixed  with 
clean  sand,  the  alcohol  evaporated  over  the  water-bath  at  a  temperature 
of  not  over  50°  C.,  and  the  residue  extracted  with  ether  or  petroleum 
spirit.  From  this  solution,  on  evaporation  of  the  solvent,  will  be  gotten 
any  hydrocarbons  present. 

An  outline  method  of  analyzing  fatty  oils  containing  foreign  mix- 
tures, due  to  Allen,*  is  given  on  the  following  page. 

The  analysis  of  soaps  is  a  most  important  matter,  as  with  the  vary- 
ing composition  of  soaps,  shown  on  page  82,  a  control  is  absolutely 
necessary  for  those  using  or  purchasing  in  quantity.  One  of  the  most 
satisfactory  schemes  for  a  complete  soap  analysis  is  that  of  A.  R.  Leeds, 
which  is  given  on  page  93.  A  similar  one,  agreeing  with  that  of  Leeds 
in  general  outlines,  is  given  by  Allen  f  in  his  excellent  work  on  ' '  Com- 
mercial Organic  Analysis."  In  the  water  determination,  great  care 
must  be  taken  to  heat  gradually  at  not  too  high  a  temperature  at  first 
(40°  to  50°  C.),  and  then  slowly  to  increase  to  100°,  and  continue  until 
no  further  loss  of  weight  is  observed. 

The  separation  of  the  mixed  fatty  acids  is  usually  only  affected  in  the 
mechanical  way  described  in  connection  with  stearic  acid.  (See  p.  74.) 
An  exact  chemical  separation  of  these  higher  fatty  acids  is  hardly 
possible.  The  most  satisfactory  method  known  is  that  of  Heintz  (Jour, 
fur  Prac.  Chem.,  Ixv,  i),  based  on  the  fractional  precipitation  of  the 
alcoholic  solution  of  the  acids  with  magnesium  acetate.  This  salt  pre- 
cipitates acids  of  the  stearic  series  more  easily  than  it  does  oleic  acid 
and  its  homologues,  and  of  the  different  homologues  of  the  stearic  series 
those  of  the  highest  molecular  weights  are  thrown  down  first. 

Commercial  glycerine  is  seldom  free  from  contamination,  and  a 
variety  of  impurities  are  liable  to  be  present.  The  impurities  of  raw 
glycerine  are  much  greater  in  number  and  amount  than  those  present 
in  the  distilled  product,  and  of  the  former,  glycerine  from  soap  lyes 

*  Allen,  Commercial  Organic  Analysis,  2d  ed.,  ii,  p.  87. 
f  Ibid.,  p.  251. 


92 


INDUSTRY   OF  THE  FATS  AND   FATTY  OILS. 


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acid  and  separate.*  Wash  residual  oil  repeatedly  by 

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ANALYTICAL  TESTS  AND  METHODS. 


93 


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94  INDUSTRY    OF    THE    FATS    AND    FATTY    OILS. 

is  much  more  impure  than  the  product  resulting  from  the  autoclave 
process.  Thus  the  mineral  matter  remaining  as  ash  in  the  case  of  a  dis- 
tilled glycerine  never  amounts  to  more  than  .2  per  cent.,  while  in  raw 
glycerine  from  soap  lyes  the  ash  usually  ranges  from  seven  to  fourteen 
per  cent.,  and  in  that  from  the  autoclave  process  considerably  less.  The 
ash  will  contain  common  salt,  and  with  it  may  be  the  chlorides  and  sul- 
phates of  lead,  iron,  zinc,  magnesium,  and  calcium.  In  glycerine  from 
soap  lyes,  sulphates  particularly  are  present.  They  may  be  accom- 
panied by  thiosulphates,  sulphites,  and  sulphides  resulting  from  the 
sulphuric  acid  saponification  of  fats.  Such  glycerines  are  purified  only 
with  great  difficulty. 

Precipitation  with  basic  acetate  of  lead  often  serves  to  distinguish 
between  a  distilled  and  an  undistilled  glycerine.  This  treatment  re- 
moves rosin,  while  rosin  oil  and  free  fatty  acids  are  removed  by  shaking 
up  the  sample  with  chloroform.  The  direct  determination  of  the  amount 
of  true  glycerine  in  commercial  samples  can  be  effected  with  moderate 
accuracy  by  the  method  of  oxidation  with  potassium  permanganate  in 
alkaline  solution,  whereby  the  glycerine  is  oxidized  to  oxalic  acid,  which 
is  then  determined  as  calcium  salt.  For  details,  the  reader  is  referred 
to  Allen's  "Commercial  Organic  Analysis,"  4th  ed.,  vol.  ii,  p.  457. 

More  accurate  is  said  to  be  the  "acetin  "  method  of  Benedikt  & 
Cantor,  which  depends  upon  the  quantitative  formation  of  glyceryl  tri- 
acetate when  glycerine  is  heated  with  acetic  anhydride.  It  is  carried  out 
as  follows :  1  to  1.5  grammes  of  the  crude  glycerine  is  heated  with  seven 
or  eight  grammes  acetic  anhydride  and  about  three  grammes  anhydrous 
sodium  acetate  for  one  to  one  and  a  half  hours  with  inverted  condenser; 
it  is  allowed  to  cool,  fifty  cubic  centimetres  of  water  are  added,  and 
the  heating  with  inverted  condenser  continued  until  it  begins  to  boil. 
When  the  oily  deposit  at  the  bottom  of  the  flask  is  dissolved  the  liquid 
is  filtered  from  impurities,  allowed  to  cool,  phenol-phthalein  added,  and 
dilute  caustic  soda  (about  twenty  grammes  per  litre)  run  in  until  neu- 
trality is  obtained.  Care  must  be  taken  not  to  exceed  that  point,  or 
glyceryl  triacetate  is  easily  saponified.  Twenty-five  cubic  centimetres 
of  strong  caustic  soda  (about  ten  per  cent,  strength)  are  now  added 
from  a  pipette.  The  mixture  is  then  heated  for  fifteen  minutes  and  the 
excess  of  alkali  titrated  back  with  normal  or  half-normal  hydrochloric 
acid.  The  strength  of  the  alkali  used  is  then  determined  by  measuring 
twenty-five  cubic  centimetres  with  the  same  pipette  and  titrating  it 
with  the  same  acid.  The  difference  in  the  two  titrations  gives  the  amount 
of  alkali  consumed  in  saponifying  the  glyceryl  triacetate,  and  from  this 
the  glycerine  can  be  calculated. 

Various  methods  have  been  proposed  for  the  analysis  of  nitro-gly- 
cerine,  based  upon  its  decomposition  by  different  reagents.  One  of  the 
simplest  and  most  satisfactory  is  that  proposed  by  Lunge,  who  uses 
for  this  purpose  his  nitrometer.  (See  p.  333.)  An  accurately- weighed 
quantity,  varying  from  .12  to  .35  gramme,  according  to  the  proportion 
of  nitro-glycerine  and  the  capacity  of  the  apparatus,  is  introduced  into 
the  cup  of  a  nitrometer  filled  with  mercury.  About  two  cubic  centi- 


BIBLIOGRAPHY  AND  STATISTICS.  95 

metres  of  concentrated  sulphuric  acid  is  then  added,  and  when  the 
nitro-glycerine  is  dissolved  the  solution  is  allowed  to  enter  the  nitro- 
meter through  the  tap.  The  cup  is  rinsed  with  successive  portions  of 
two  cubic  centimetres  and  one  cubic  centimetre  of  strong  sulphuric  acid, 
which  are  allowed  to  enter  as  before,  and  the  contents  of  the  nitrometer 
are  then  thoroughly  agitated  in  the  usual  way,  and  the  volume  of  nitric 
oxide  evolved  read  off  after  standing  about  fifteen  minutes.  The 
volume  of  gas  in  cubic  centimetres  at  the  standard  pressure  and  temper- 
ature, multiplied  by  3.37,  gives  the  weight  of  nitro-glycerine  in  milli- 
grammes. Hempel  states  that  the  total  volume  of  five  cubic  centimetres 
of  sulphuric  acid  must  not  be  departed  from ;  with  less  than  that  volume 
the  reaction  proceeds  too  slowly,  and  with  more  the  results  are  too  low. 
In  the  analysis  of  dynamite,  the  nitro-glycerine  may  be  conveniently 
determined  by  exhausting  the  dried  sample  with  anhydrous  ether,  pref- 
erably in  a  Soxhlet  tube  (see  p.  86),  and  weighing  the  insoluble  residue. 
The  nitro-glycerine  is  estimated  from  the  loss,  and,  in  the  absence  of 
other  substances  soluble  in  ether,  such  as  camphor,  resin,  etc.,  this  is  the 
most  satisfactory  way.  A  complete  scheme  for  the  analysis  of  all  nitro- 
glycerine preparations  will  be  found  in  Allen,  3d  ed.,  vol.  ii,  Part  i, 
p.  339. 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

1867. — Die  Chemie  der  Austrocknenden  Oele,  G.  J.  Mulder,  Berlin. 

1876. — The  Oil  Seeds  and  Oils  in  the  India  Museum,  M.  C.  Cooke,  London. 

1879. — Commercial  Products  of  the  Sea,  P.  L.  Simmonds,  London. 

Die  Nutzpflanzen  aller  Zonen,  L.  Wittmack,  Berlin. 
1881. — Matieres  Premieres  Organiques,  G.  Pennetier,  Paris. 

Soap  and  Candles,  R.  S.  Christiani,  Philadelphia  and  London. 
1882. — Die  Trocknenden  Oelen,  L.  E.  Andes,  Braunschweig. 

Das  Glycerin,  Koppe,  Wien. 
1885. — Soap  and  Candles,  W.  L.  Carpenter,  London  and  New  York. 

Das  Wachs  und  seine  technische  Verwendung,  S.  Sedna,  Wien. 
1887. — The  Art  of  Soap-making,  A.  Watt,  London. 

Guide  pratique  du  Fabricant  de  Savons,  etc.,  Calmels  et  Saulnier,  Paris. 

Thgorie  et  pratique  de  la  Fabrication  des  Bougies  et  des  Savons,  Larue  et 
Droux,  Paris. 

Traite"  pratique  de  Savonnerie,  E.  Morritz,  Paris. 
1888. — Soap  and  Candles,  J.  Cameron,  London. 

Manufacture  of  Soap  and  Candles,  W.  T.  Brannt,  Philadelphia  and  London. 

Handbuch  der  praktischen  Kerzenfabrikation,  Al.  Englehardt,  Wien. 

Seifenfabrikation,  2  Bds.,  Al.  Englehardt,  Wien. 

Report  of  House  Committee  on  Compound  Lard,  Washington. 

1889. — Lard  and  Lard  Adulteration,  H.  W.  Wiley    (Bulletin  No.  13),  Washington, 
D.  C. 

Die  fetten  Oele  des  Pflanzen-  und  Thierreiches,  Bornemann,  \Veimar. 

Der  praktische  Seifenseider,  H.  Fischer,  Weimar. 

Die  Fetten  Oele,  G.  Bornemann,  Weimar. 

Tropical  Agriculture,  P.  L.  Simmonds,  3d  ed.,  London  and  New  York. 
1890. — Die  Untersuchungen  der  Fette,  Oele,  Wachsarten,  etc.,  C.  Schaedler,  Leipzig. 

A  Dictionary  of  Explosives,  J.  P.  Cundill,  London. 

A  Hand-Book  of  Modern  Explosives,  M.  Eissler,  New  York. 

Les  Corps  Gras,  A.  M.  Villon,  Paris. 


96  INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 

1891. — Leg  Matieres  Grasses,  G.  Beauvisage,  Paris. 

1892. — Chemie  analytique  du  Matigres  Grasses,  Ferd.  Jean,  Paris. 

Die  Technologic  der  Fette  und  Oele,  C.  Schaedler,  2te  Auf.,  Leipzig. 
1893. — Les  Explosives,  Roman,  Paris. 

Soap  Manufacture,  W.  L.  Gadd,  London. 
Vegetabilische  und  Mineral-Maschinenole,  L.  E.  Andes,  Wien. 
1894. — Die  Schmiermittel,  Jos.  Grossmann,  Wiesbaden. 

Oils,  Fats,  and  Waxes,  C.  R.  Alder  Wright,  London. 
Savons  et  Bougies,  J.  Lefevre,  Paris. 

1895. — Die  Industrie  der  Explosivestotfe,  O.  Guttmann,  Braunschweig. 
Die  Explosivestoffe,  Fr.  Bockmann,  2te  Auf.,  Wien  and  Leipzig. 
1896. — Animal  and  Vegetable  Fats  and  Oils,  W.  T.  Brannt,  2d  ed.,  Philadelphia. 
1897. — Vegetable  Fats  and  Oils,  L.  E.  Andes,  translated  into  English,  London. 
Lubricating  Oils,  Fats,  and  Greases,  G.  H.  Hurst,  London. 
Animal  Fats  and  Oils,  L.  E.  Andes,  translated  by  C.  Salter,  London. 
Lubricants,  Oils,  and  Greases,  I.  I.  Redwood,  New  York. 
1899. — Die  Seifenfabrikation,  F.  Wiltner,  Wien. 

Soaps:  A  Practical  Treatise,  G.  H.  Hurst,  London. 
1906. — The  Manufacture  of   Lubricants,   Shoe  Polishes  and  Leather  Dressings,   R. 

Brunner,  translated  from  6th  German  ed.  by  Chas.  Salter,  London. 
Technologic  et  Analyse  chimique  des  Huiles,  Graisses  et  Cires,  E.  Bontoux, 

Paris. 

Handbuch  der  Seifen-fabrikation,  C.  Deite,  3rd  Auf.,  Berlin. 
1907. — Die  gewinnung  und  Verarbeitung  des  Glycerins,  Dr.  B.  Lach,  Halle. 
1908. — Die  Stearin-fabrikation  von  Bela  Lach,  Knapp  Verlag,  Halle. 

Analyse  der  Fette  und  Wachsarten,  Benedikt  Ulzer,  5th  Auf.,  Berlin. 
Handbuch  der  Chemie  und  Technologic  der  Oele  und  Fette,  L.  Ubbelohde, 

Leipzig. 
1909. — Chemical  Technology  and  Analysis  of  Oils,  Fats,  and  Waxes,  J.  Lewkowitsch, 

4th  edition,  3  vols,  MacMillan  &  Co.,  London  and  New  York. 
Anleitung  zur  Chemischen  und  Physikalischen  Untersuchung  der  Sprengstoffe, 

etc.,  von  H.  Kast,  Vieweg  und  Sohn,  Braunschweig. 
The  Rise  and  Progress  of  the  British  Explosives  Industry,  Whittaker  &  Co.. 

London  and  New  York. 

.     Linseed  Oil  and  Other  Seed  Oils,  W.  D.  Ennis,  New  York. 
1910. — Technologic  der  Fette  und  Oele,  Gustav  Hefter,  vols.  i,  ii,  iii,  Julius  Springer, 

Berlin. 

Allen's   Commercial   Organic  Analysis,   4th  edition,  vols.   ii   and  iii,  Phila- 
delphia. 
1911.— Handbook  of  Oil  Analysis,  A.  H.  Gill,  6th  edition,  Philadelphia. 

STATISTICS. 

1.  OF  OILS,  FATS,  AND  WAXES. — Of  the  production  of  the  various 
vegetable  and  animal  oils,  fats,  and  waxes  the  figures  are  fragmentary. 
While  they  do  not  always  give  a  proper  view  of  these  industries,  they 
will  suffice  to  indicate  in  a  general  way  the  degree  of  their  development. 

The  figures  for  importations  and  exportations  of  this  class  of  prod- 
ucts will  in  many  cases  give  a  better  idea  of  the  several  fat  industries. 

Importations  of  Oils,  Fats,  and  Related  Products  into  the  United  States. 

1905.                                   1906.  1907. 

Coeoanut  oil  43,773,208  Ibs.  43,821,756  Ibs.  35,555,603  Ibs. 

Value  $2,568,048  $2,601,665  $2,628,016 

Rape   and   hemp-seed   oils 730,868  gals.           1,135';203  gals.  806,033  gals. 

value    $264,025                    $383,775  $405,575 

Olive  oil    (salad) 1,559,583  gals.           1,812,412  gals.  3,389,516  gals. 

Value   $1,836,942  $2,113,872  $2,724,500 


BIBLIOGRAPHY  AND  STATISTICS. 


97 


Importations  of  Oils,  Fats,  and  Related  Products  into  the  United  States. 
( Continued. ) 

1905.  1906.                                    1907. 

Olive  oil  (not  salad) 1,804,843  gals.  2,538,038  gals.           1,845,701  gals. 

Value   $757,119  $1,106,142                     $794,574 

Palm  oil    19,873,557  Ibs.  23,475,595  Ibs.           29,475,595  Ibs. 

Value  $1,081,013  $1,296,182                  $1,888,660 

Sesame  oil    1,394,975  Ibs.  1,354,456  Ibs.             1,600,410  Ibs. 

Value   $91,314  $108,690                    $121,607 

Cocoa   butter    2,732,897  Ibs.  3,350,025  Ibs.             4,418,839  Ibs. 

Value     $615,991  $818,847                  $1,226,504 

Beeswax   374,219  Ibs.  585,636  Ibs.                918,995  Ibs. 

Value   $101,131  $168,015                    $265,172 

Soap,    castile    4,588,531  Ibs.  4,693,717  Ibs.             5,153,565  Ibs. 

Value   $294,540  $304,818                     $346,383 

Soap,   toilet    1,013,651  Ibs.  1,115,000  Ibs.             1,207,307  Ibs. 

Value   $446,526  $477,891                      $520,600 

Glycerine,   crude    26,248,514  Ibs.  33,276,728  Ibs.           37,136,812  Ibs. 

Value $1,960,538  $2,228,956                  $2,375,764 

(Oil,  Paint  and  Drug  Reporter.) 
Exportations  of  Oil,  Fats,  and  Related  Products  from  the  United  States. 

1905.  1906.  1907. 

Corn  oil  3,108,917  gals.  3,833,251  gals.  3,041,269  gals. 

Value  $890,937  $1,172,206  $1,083,929 

Cotton-seed  oil 51,535,580  gals.  43,793,519  gals.  41,880,304  gals. 

Value  $15,125,802  $13,673,370  $17,074,403 

Cotton-seed 21,101,129  Ibs.  23,717,326  Ibs.  17,628,111  Ibs. 

Value  $235,833  $268,330  $209,493 

Flax-seed 1,338  bush.  5,988,519  bush.  6,336,310bush. 

Value  '.".  $1,738  $7,495,748  $7,990,383 

Soap,  toilet,  value $888,838  $1,082,893  $1,144,879 

Soaps,  other  45,321,281  Ibs.  42,410,534  Ibs.  65,183,460  Ibs. 

Value $1,781,893  $1,698,286  $2,661,218 

Tallow  63,536,992  Ibs.  97,567,156  Ibs.  127,857,739  Ibs. 

Value  $3,022,173  $4,791,025  $7,182,688 

Lard  610,238,899  Ibs.  741,516,886  Ibs.  627,559,660  Ibs. 

Value $47,243,181  $60,132,091  $57,497,980 

Lard,  compound,  etc.  $3,613,235  $4,154,183  $6,166,910 

Candles  8,793,502  Ibs.  7,972,871  Ibs.  5,203,736  Ibs. 

Value  $701,357  $609,188  $473,235 

Corn-cake 24,171,127  Ibs.  48,420,942  Ibs.  56,808,972  Ibs. 

Value  $278,526  $605,346  $677,156 

Cotton-seed  cake 1,251,907,996  Ibs.  1,110,834,678  Ibs.  1,340,967,136  Ibs. 

Value  $13,897,178  $13,073,150  $17,062,594 

Linseed  cake  618,498,525  Ibs.  758,916,364  Ibs.  665,936,164  Ibs. 

Value  $7,600,907  $10,313,118  $8,675,877 

(Oil,  Paint  and  Drug  Reporter.) 

Statistics  of  English  Trade  in  Oils,  Fats,  and  Related  Products. 

1900.  1901.                          1902. 

Imports    £40,929,185  £43,874,659         £46,953,142 

Exports     4,804,370  5,032,143             5,501,008 


Less    re-exports    . .     £3,861,132 


£3,285,252 


£2,984,592 


£41,782,223         £45,621,550         £49,469,558 

(Lewkowitsch — Lect.  before  Society  of  Arts.) 

7 


98 


INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 


Statistics  of  German  Importations  of  Fats  and  Fatty  Oils  in  1905. 


Value  in  marks. 

Lard    86,100,000 

Butter    71,800,000 

Oleomargarine   22,600,000 

Cotton-seed  oil    .'.... 17,300,000 

Tallow  (beef  and  mutton)    ..  15,000,000 

Fish   oil    5,600,000 

Olive  oil   4,900,000 

Palm  oil   3,600,000 

Linseed   oil    900,000 


Value  in  marks. 

Beeswax    •  7,400,000 

Vegetable  wax 1,700,000 

Linseed     68,600,000 

Palm  nut  and  copra 60,300,000 

Oil  cake    51,000,000 

Rape  seed 31,700,0()J 

Sesame  seed   12,100,000 

Poppy   seed    8,300,000 

Earth-nuts    4,600,000 


Cocoa-nut  Oil. — The  annual  yield  of  nuts  in  Ceylon  may  be  taken  at 
1,100,000,000.  In  1898  the  exports  of  cocoa-nut  oil  from  this  island 
amounted  to  435,000  hundredweight,  and  in  1899  to  400,000  hundred- 
weight, besides  large  quantities  of  "copra  "  (the  dried  pulp  of  the  cocoa- 
nut)  and  cocoa-nuts.  Large  amounts  are  also  exported  from  the  Eastern 
Archipelago,  from  British  India,  and  from  the  Pacific  Islands.  The  nuts 
are  also  exported  from  the  West  Indies,  from  Central  America,  and  from 
Brazil. 

Palm,  Oil. — The  exportation  of  palm  nuts  from  Southern  Africa, 
according  to  Dr.  von  Scherzer,  reaches  1,300,000  metric  centners  an- 
nually, of  which  the  greater  part  goes  to  France.  The  exportation  of 
nuts  from  British  India,  Siam,  Cochin-China,  China,  South-Sea  Islands, 
and  Brazil  together  amounts  to  600,000  metric  centners. 

Olive  oil  is  produced  chiefly  in  Mediterranean  lands  and  in  the  East. 
The  area  under  olive  culture  in  Italy  is  now  2,258,000  acres.  The  oil 
production  of  1905-06  was  stated  to  have  been  3,400,000  hectolitres, 
while  that  of  1906-7  was  but  1,800,000  hectolitres.  The  export  of  olive 
oil  from  Italy  ranges  from  50,000,000  kilos,  to  92,000,000  annually,  ac- 
cording to  the  crop  of  olives  (Simmond's  Tropical  Agriculture,  p.  394). 
Spain  has  some  2,500,000  acres  devoted  to  olive  culture,  and  the  average 
annual  production  of  oil  for  the  last  five  years  has  been  2,976,384  metric 
centners.  Of  this  the  home  consumption,  for  food,  lighting,  soap-making, 
etc.,  took  2,754,064  metric  centners,  leaving  222,320  metric  centners  for 
export.  France  had,  a  few  years  ago,  317,800  acres  of  olives  under  cul- 
tivation, producing  7,318,352  bushels  of  fruit  and  392,618  hundred- 
weight of  oil.  The  total  Greek  production  in  1907  was  564,761  metric 
tons  of  oil.  The  Algerian  production  was  55,239,000  kilos,  of  fruit, 
yielding  1,543,400  hectolitres  (of  twenty-two  gallons)  of  oil.  (Spon.) 
The  exportation  of  Turkey  and  the  Turkish  provinces  is  estimated  at 
900,000  metric  centners  annually.  (Heinzerling.) 

The  production  of  olive  oil  in  California  was  stated  at  the  tariff 
hearings  in  1908  to  be  350,000  gallons  annually. 

Rape  or  colza  oil  is  cultivated  in  Germany,  France,  Austria,  Hun- 
gary, Russia,  Rumania,  and  India.  The  area  in  Germany  planted  with 
the  different  varieties  of  brassica  amounted  in  1882  to  445,000  acres,  the 
crop  of  rape  seed  to  1,882,000  metric  centners,  valued  at  50,500,000 
marks. 


BIBLIOGRAPHY  AND  STATISTICS.  99 

England  imports  some  800,000  metric  centners  of  rape  seed  annually, 
and  produces  quite  an  amount.  Austria  presses  for  oil  about  550,000 
metric  centners  of  rape  seed  annually,  obtaining  200,000  to  225,000 
metric  centners  of  oil.  The  total  consumption  of  rape  and  colza  oil  in 
Europe  is  estimated  at  2,800,000  to  3,000,000  metric  centners  per  an- 
num, valued  at  170,000,000  to  175,000,000  marks.  (Heinzerling.) 

The  exportation  of  rape  seed  from  Russia  in  1879  amounted  to  1,294,- 
728  bushels,  and  from  Roumanian  ports,  on  the  Danube,  in  1878,  to 
938,376  bushels. 

Sesame  Oil. — The  seeds  come  chiefly  from  the  East  Indies  and  the 
Levant,  and  the  oil  is  pressed  in  Marseilles  and  Trieste.  British  India 
exported  in  1885,  2,646,484  hundredweight;  in  1886,  1,759,343  hundred- 
weight; and  in  1887,  2,121,119  hundredweight.  France  imports  some- 
what more  than  1,000,000  metric  centners;  England,  250,000  metric 
centners;  Italy,  150,000  metric  centners;  and  Germany,  140,000  metric 
centners  of  sesame  seeds. 

Ground-nut  Oil. — The  ground-nut  (pea-nut),  while  indigenous  to 
America,  is  now  cultivated,  for  the  oil  it  contains,  in  Africa,  India,  the 
West  Indies,  and  Brazil.  The  American  production,  located  chiefly  in 
the  States  of  North  Carolina,  Virginia,  Tennessee,  amounts  to  an  aver- 
age of  3,500,000  bushels,  or  77,000,000  pounds.  The  production  of  1899 
exceeded  the  avearge,  amounting  to  4,500,000  bushels.  The  average  pro- 
duction of  "Spanish  pea-nuts  "  in  the  United  States  amounts  to  16,500,- 
000  pounds.  About  400,000,000  pounds  are  annually  exported  from 
India  and  Africa,  of  which  about  half  goes  to  Marseilles  to  be  expressed 
for  oil. 

It  is  estimated  that  3,250,000  bushels  are  annually  eaten  in  the 
United  States. 

Cotton-seed  Oil. — The  growth  of  the  cotton-seed  industry  in  the 
United  States  as  shown  by  the  Census  Report  of  1905  has  been  very 
great.  This  is  illustrated  by  the  following  figures: 

1890.  1900.  1905. 

Value  of  materials    $14,363,126  $45,165,823  $80,039,963 

Value  of  products 19,335,947  58,726,632  96,407,621 

The  amount  of  cotton-seed  crushed  increased  from  2,479,386  tons  in 
1900  to  3,345,370  tons  in  1905. 

In  1905,  one  ton  of  cotton-seed  yielded  on  an  average  40  gallons  crude 
oil  (300  pounds),  813  pounds  meal,  725  pounds  hulls,  35  pounds  linters 
and  127  pounds  of  waste. 

Of  this  annual  production  of  crude  cotton-seed  oil,  perhaps  one- 
fourth  goes  into  the  production  of  "compound  lard,"  and  the  rest  is 
partly  exported  as  cotton-seed  oil,  partly  used  in  admixture  with  drying 
oils,  and  partly  as  soap-stock. 

In  Europe,  England  is  the  chief  country  extracting  the  oil  from  the 
cotton-seed,  which  comes  chiefly  from  Egypt.  The  imports  of  seeds  into 
England  for  1886  were  25,701  tons;  for  1887,  276,570  tons;  for  1888, 
255,500  tons. 


100  INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 

Hemp-seed  oil  is  produced  chiefly  in  Russia.  The  exports  of  hemp 
seed  from  Riga  in  1878  were  629,520  bushels,  and  in  1879,  725,809  poods 
(of  thirty-six  pounds)  of  seed  and  573  poods  of  the  oil.  (Spon's  ''En- 
cyclopedia.") 

Linseed  Oil. — The  supplies  of  linseed  oil  come  from  all  countries,  but 
most  largely  from  Russia,  the  United  States,  and  Argentina.  The 
world's  crop  of  linseed  in  recent  years  has  been  as  follows: 

1903.  1904.  1905. 

Bushels.  Bushels.  Bushels. 

United    States    27,301,000  23,401,000  28,478,000 

Canada  and  Mexico    957,000  843,000  907,000 

Argentina  30,076,000  36,912,000  29,133,000 

Uruguay    8,176,000  5,530,000  6,000,000 

Austria-Hungary     1,442,000  1,380,000  1,592,000 

Russia    19,544,000  20,190,000  18,900,000 

Other    European    countries     3,631,000  1,609,000  1,666,000 

India     19,263,000  22,873,000  13,856,000 

Miscellaneous    65,000  36,000  35,000 


Total 110,455,000  112,774,000  100,607,000 

(Year  Book  of  Agriculture,  U.  S.,  1906.) 

Cocoa  Product  of  the  World. 

1904.  1905.  1906. 

Pounds.  Pounds.  Pounds. 

St.   Thomas    45,252,000  55,952,000  51,800,000 

Ecuador    62,685,000  46,579,000  54,900,000 

Brazil     51,059,000  46,496,000  60,400,000 

Trinidad     40,949,000  44,133,000  35,100,000 

Santo   Domingo    29,890,000  28,185,000  30,200,000 

Venezuela     28,768,000  25,795,000  24,300,000 

Gold   Coast    (Lagas)     12,540,000  12,491,000  13,400,000 

Grenada   13,727,000  12,028,000  10,400,000 

Other  countries    38,223,000  40,015,000  46,200,000 


323,093,000  311,674,000  326,000,000 

Fish  Oils. — The  amounts  of  sperm,  whale,  and  fish  oils  of  all  kinds 
obtained  annually,  according  to  Mulhall,*  are:  sperm  and  whale  oil, 
1,485  000  hectolitres  (32,670,000  gallons)  ;  fish  oils  of  other  kinds, 
1,170,000  hectolitres  (25,740,000  gallons),  and  oil  from  sea-birds  58,500 
hectolitres  (1,270,000  gallons). 

The  value  of  the  fish  oils  exported  from  Newfoundland  in  recent  years 
is  given  as  follows: 

1906.  1907. 

Cod-liver  oil,  crude $354,352  $358,713 

Cod-liver  oil,   refined    34,995  31,735 

Seal  oil    297,430  447,967 

Whale   oil    222,76,1  173,011 

*  Mulhall,  Production  and  Consumption,  p.  142. 


BIBLIOGRAPHY  AND  STATISTICS. 


101 


The  Norwegian  cod-liver  oil  production  from  the  three  districts  of 
Lofoten,  Romsdal,  and  Lodde  is  thus  given  on  the  authority  of  F.  P. 
Moller  (Cod-liver  Oil  and  Chemistry,  London,  1895)  : 


YEAR. 

Number  of  fish. 

Barrels  of  com- 
mon liver  oil. 

Barrels  of  steam- 
prepared  liver  oil. 

1890  

51,614,000 

58,535 

21,173 

1891  

40,880,000 

33,815 

22,331 

1892  .    . 

44,212  000 

47  051 

16  331 

1893  

47,738,000 

41,851 

18  757 

1894  

52,484,000 

34,670 

21,294 

The  production  of  Norway  in  recent  years  is  given  as  follows:    In 
1905,  42,000  hectolitres ;  in  1907,  46,809  hectolitres. 

The  value  of  the  cod-liver  oil  exported  from  Norway  is  thus  given : 


1906. 
Kronen. 

5,519,000 


1907. 
Kronen. 

4,724,900 


Spermaceti  and  Sperm  Oil. — The  production  of  spermaceti  in  the 
American  whale-fisheries  was  1,300,959  gallons  in  1878,  and  1,285,454 
gallons  in  1879.  The  exports  of  sperm  oil  from  New  York  in  1878  were 
912,603  gallons,  and  in  1879,  1,089,137  gallons.  (Spon's  "Encyclo- 
pedia.") 

Lard  and  Lard  Oil. — The  production  of  lard  in  the  United  States 
during  recent  years  is  thus  given  by  the  Cincinnati  Price  Current: 


1884-85. 
Pounds. 


1885-86. 
Pounds. 


1886-87. 
Pounds. 


1887-88. 
Pounds. 


1888-89. 
Pounds. 


[1889-90. 
Pounds. 


480,405,000  514,230,000  527,032,000  487,179,000  483,902,000  624,227,000 

Of  this  production  from  one-third  to  one-half  is  "compound  lard," 
or  lard  admixed  with  cotton-seed  oil  and  beef  stearine. 

Tallow. — The  production  of  tallow  for  all  European  countries  for  the 
year  1882,  according  to  Mulhall,*  amounted  to  355,700  tons,  for  the 
United  States  to  330,000  tons,  and  all  other  countries,  60,000  tons,  mak- 
ing a  total  of  745,700  tons.  The  exportations  of  Russian  tallow  have 
greatly  diminished  in  recent  years;  they  were  40,300  tons  in  1860,  21,- 
100  tons  in  1870,  and  10,400  tons  in  1880.  The  exportations  from  the 
United  States,  River  Plate  in  South  America,  and  Australia,  on  the  other 
hand,  have  increased,  especially  the  first  and  the  last  of  these.  In  the 
year  1883  the  exportations  of  tallow  were  as  follows:  From  the  United 
States,  45,000  tons;  from  Australia,  28,000  tons;  from  Argentine  Re- 
public, 10,500  tons,  and  from  Uruguay,  12,000  tons.  (Heinzerling.) 

Wool  Fat.— In  1899,  ]  ,038,000  tons  of  raw  wool  were  worked  for  the 
extraction  of  the  wool  fat  (Donath  and  Margosches,  Vortrage.) 

Chinese  or  Insect  Wax. — The  amount  annually  produced  is  valued 
by  Professor  Thistleton  Dyer,  of  Kew  Gardens,  England,  at  £600,000. 


Mulhall,  Dictionary  of  Statistics,  p.  434. 


102 


INDUSTRY  OF  THE  FATS  AND  FATTY  OILS. 


Carnauba  Wax. — The  exportation  of  this  wax  from  Brazil  in  recent 
years  were  as  follows: 

190L  1502.  1903.  1904. 

Quantity  in  tons   997  1926  1897  2559 

Value  in  milreis 1044  2662  3291  6316 

Value  in  marks   996  2562  4239  8567 

Japan  Wax. — The  exportations  from  Japan  were  in  1906  2,348,175 
kilos.,  valued  at  $970,092. 

Soaps. — The  production  of  the  United  Kingdom  for  1907  was  as  fol- 
lows :  Soap,  737,500,000  Ibs.,  valued  at  $40,933,600 ;  candles,  102,617,000 
Ibs.,  valued  at  $8,044,800.  In  1909  the  Census  Bureau  reported  the  pro- 
duction of  soaps  of  all  kinds  in  the  United  States  as  1,388,972,065  Ibs., 
valued  at  $57,358,431. 

Candles. — Price's  Patent  Candle  Co.  of  England  manufacture  yearly 
7000  tons  of  paraffin  candles  and  3000  tons  of  stearine  candles.  The 
Saxon  paraffin  works  manufacture  yearly  6750  tons  of  paraffin  and 
composition  candles. 

Glycerine. — The  total  output  of  crude  glycerine  in  the  world  has 
been  stated  to  be  40,000  tons  per  annum,  of  which  14,000  tons  are 
obtained  in  soap  manufacture  and  26,000  tons  in  stearine  manufacture. 
The  glycerine  from  these  two  sources  is  produced  as  follows: 

From  soap-  From  stearic  acid 

making.  manufacture. 

England     5500  tons.  1200  tons. 

France    3500  6000 

Germany     2000  3000 

United   States    3000  3000 

Holland    2000 

Austria     2000 

Russia     2000 

Belgium     1800 

Italy 1800 

Spain    1500 

Other  countries   1700 

The  development  of  the  glycerine  and  nitro-glycerine  production  in 
the  United  States  has  been  shown  in  the  Census  Report  of  1905 : 

1900.  1905. 

Production  of  glycerine  15,383,778  Ibs.  19,311,997  Ibs. 

Value  $1,893,886  $2,397,205 

Production  of  nitro-glycerine  35,280,498  Ibs.  51,579,270  Ibs. 

Value  ." $5,532,570  $7,730,175 

Production  of  dynamite  42,923  tons  65,460  tons 

Value    ". $8,247,223  $12,900,193 


EAW  MATERIALS.  103 


CHAPTER    III. 

INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

I.  Raw  Materials. 

1.  ESSENTIAL  OILS. — The  essential  or  volatile  oils,  as  they  are  termed, 
are  found  extensively  distributed  throughout  the  vegetable  kingdom. 
They  occur  in  almost  all  parts  of  the  plants  except  the  cotyledons  of  the 
seeds,  in  which,  in  general,  the  fixed  or  fatty  oils  are  contained.  The 
essential  oils  impart  the  peculiar  and  characteristic  odors  to  the  plants; 
they  furnish  us  our  perfumes,  spices,  and  aromatics,  and  many  of  them 
possess  valuable  medicinal  properties. 

The  essential  or  volatile  vegetable  oils  are  procured  in  several  ways : 
(1)  by  distillation;  (2)  by  absorption  or  "enfleurage  ";  (3)  by  means 
of  solvents;  (4)  by  expression;  and  (5)  by  maceration. 

In  the  distillation  method  the  plants  are  put  into  the  still  along  with 
about  an  equal  weight  of  water,  either  with  or  without  previous  soak- 
ing, and  the  distillation  carried  on  rapidly.  If  necessary,  the  water  that 
separates  from  the  oil  in  the  receiver  is  returned  to  the  still  and  driven 
over  a  second  or  third  time.  The  separation  of  the  oil  and  water  is 
effected  in  what  is  termed  a  "Florentine  receiver,"  from  the  bottom 
of  which  the  water  can  be  siphoned  off  without  disturbing  the  oily  layer. 
The  odors  of  some  flowers,  such  as  jessamine  and  mignonette,  are  too 
delicate  to  bear  heat,  and  for  these  the  process  of  absorption,  or  "en- 
fleurage,"  as  it  is  called  in  the  south  of  France,  is  employed.  Sheets 
of  glass  in  wooden  frames,  called  chassis,  are  coated  in  their  upper  and 
lower  surfaces  with  grease  about  a  tenth  of  an  inch  in  thickness.  The 
flowers  are  spread  upon  this  grease,  and  a  number  of  frames  are  super- 
imposed one  upon  another.  After  a  day  or  two  the  flowers  are  carefully 
removed  and  replaced  by  fresh  ones,  and  this  is  continued  for  two  or 
three  months,  till  the  fat  is  impregnated  with  the  odors.  It  is  then 
removed  and  extracted  with  alcohol.  Recently  the  grease  has  been  re- 
placed in  some  cases  by  soft  paraffin,  glycerine,  or  vaseline. 

For  the  extraction  by  solvents,  light  petroleum  ether,  carbon  disul- 
phide,  and  latterly  carbon  tetrachloride  are  employed,  and  the  solvent 
recovered  by  distillation.  The  essential  oils  of  lemons  and  oranges  of 
commerce,  and  some  other  fruits,  are  chiefly  obtained  by  submitting 
the  rind  to  powerful  pressure.  The  oils  are  more  fragrant  but  not  so 
white  as  when  distilled,  and  the  process  is  only  adapted  for  substances 
which  are  very  rich  in  essential  oils.  Flowers  with  very  delicate  per- 
fume, such  as  those  of  the  bitter  orange,  violets,  etc.,  which  would  be 
spoiled  by  distillation,  are  treated  by  maceration.  The  medium  used 
for  infusion  is  clarified  beef  or  mutton  suet  or  lard.  The  fat  is  melted, 


104          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

the  flowers  immersed,  and  the  mixture  stirred  occasionally  for  a  day  or 
so.  The  exhausted  flowers  are  removed  and  fresh  ones  introduced,  and 
such  renewals  are  continued  till  it  is  judged  that  the  fat  is  sufficiently 
charged  with  the  oil. 

The  essential  oils  are  usually  more  limpid  and  less  unctuous  than  the 
fixed  oils,  but  some  of  them,  when  in  the  crude  state,  may  be  quite  thick 
or  even  semi-solid  from  admixtures  of  solid  and  crystalline  ingredients 
with  the  more  liquid  portion.  Their  odor  is  that  of  the  plants  which 
yield  them,  and  is  usually  powerful ;  their  taste  is  pungent  and  burning. 
They  mix  in  all  proportions  with  the  fixed  oils,  dissolve  in  both  alcohol 
and  ether,  and  are  sparingly  soluble  in  water,  forming  "perfumed  "  or 
"medicated  water."  They  are  not  saponifiable.  Their  boiling-points 
usually  range  from  310°  to  325°  F.  (154.5°  to  162.7°  C.),  although  in 
some  oils  the  hydrocarbons  boil  at  356°  F.  (180°  C.)  or  even  higher. 
They  are,  however,  capable  in  most  cases  of  being  distilled  in  a  current 
of  steam.  In  specific  gravity  they  vary  from  oil  of  citron  .850  to  oil 
of  wintergreen  1.185  at  15°  C. 

Chemically,  essential  oils  are  in  the  main  mixtures  of  a  class  of 
hydrocarbons  known  as  terpenes  and  oxygen-containing  substances,  such 
as  alcohols,  esters,  ketones,  aldehydes,  and  phenols.  These  oxygenated 
bodies  when  solid  have  been  termed  camphors. 

I.  The  oils  which  do  not  contain  oxygen  are  composed  of  hydrocar- 
bons of  what  is  called  the  terpene  series.  These  seem  to  be  of  a  common 
formula,  which  is  C10H16  or  a  multiple  of  this.  We  may  distinguish 
several  groups. 

1.  Hemiterpenes,  C5H8. — A  hydrocarbon  of  this  formula  is  yielded 
when  caoutchouc  is  destructively  distilled. 

2.  Terpenes,  C10H16. — The  true  terpenes.    Of  these  some  six  or  eight 
distinct  compounds  have  been  obtained,  but  they  may  exist  in  different 
physical  modifications  according  as  they  are  right  or  left  rotatory  or  in- 
active to  polarized  light. 

3.  Sesquiterpenes,  C15H24. — This  group  includes  the  hydrocarbons  of 
oils  of  cedar,  cubebs,  and  cloves. 

4.  Diterpenes,  C20H32,  include  colophene,  obtained  in  the  treatment 
of  oil  of  turpentine,  and  possibly  others. 

5.  Poly  terpenes,  (C10H16)n,   include   the   polymerized   hydrocarbons 
of  caoutchouc  and  gutta-percha. 

II.  The  oils  which  contain  oxygen  may  owe  this  to  one  of  several 
classes  of  oxygen  compounds. 

1.  Camphors. — This  group  includes  common  or  Japan  camphor,  bor- 
neol,  cineol,  or  eucalyptol,  menthol.    These  bodies  are  either  alcohols  or 
ketones  in  chemical  character. 

2.  Unsaturated  Alcohols  and  Aldehydes. — A  number  of  compounds 
of  this  class  have  recently  been  identified  as  constituting  important 
odoriferous  principles  in  oils.     Thus,  geraniol,  OB  rhodinol  and  linalool 
(coriandrol)   are  unsaturated  alcohols,  while  citral  and  citronellal  are 
unsaturated  aldehydes. 

3.  Esters  or  Compound  Ethers  of  Alcohols. — The  formic,  acetic,  and 


RAW  MATERIALS.  105 

valeric  ethers  of  borneol  and  the  formic  and  acetic  ethers  of  linalool 
and  geraniol  are  all  found  natural  in  essential  oils.  Methyl  salicylate 
is  another  compound  ether,  constituting  the  main  constituent  of  oil  of 
wintergreen. 

4.  Phenols, — Thymol,  of  oil  of  thyme,  and  carvacrol,  of  origanum  oil, 
belong  to  this  class. 

5.  Ethers  of  the  Phenols. — Anethol,  of  anise  oil,  eugenol,  of  oil  of 
cloves,  and  safrol,  of  oil  of  sassafras,  belong  here. 

6.  Aromatic  Aldehydes. — Benzaldehyde,  salicyl  aldehyde,  anisic  alde- 
hyde, vanillin,  cumin  aldehyde,  and  cinnamic  aldehyde  belong  to  this 
class. 

III.  The  oils  which  contain  sulphur  seem  to  belong  to  two  classes. 

1.  Sulphides  of  Organic  Radicals. — Garlic  oil,  onion  oil,  leek  oil,  and 
similar  oils  contain  allyl  and  vinyl  sulphides. 

2.  Sulpkocyanates  of  Organic  Radicals.— Mustard  oil  and  some  others 
contain  allyl  sulphocyanate. 

Oil  of  Turpentine. — This  oil  is  produced  by  all  the  Conifer  a  in 
greater  or  less  amount.  It  flows  from  cuts  in  the  tree  as  a  balsam  (see 
p.  107),  known  as  turpentine.  This,,  on  distillation  with  steam,  yields  the 
volatile  oil  of  turpentine,  and  there  remains  behind  the  resin  (colo- 
phony resin)  commonly  known  as  "rosin."  While  a  number  of  minor 
varieties  of  turpentine  are  known,  such  as  Venetian,  Hungarian,  Stras- 
burg,  Chios  turpentines,  and  Canada  balsam,  which  are  of  pharma- 
ceutical value,  but  three  commercially  important  varieties  of  oil  of  tur- 
pentine need  to  be  noted.  They  are  English  or  American  oil  of  tur- 
pentine, from  Pinus  australis  and  Pinus  tceda,  collected  in  North  and 
South  Carolina  and  Georgia;  the  French  oil  of  turpentine  from  Pinus 
maritima,  collected  in  the  neighborhood  of  Bordeaux;  and  the  Russian 
or  German  oil  of  turpentine,  from  Pinus  sylvestris.  Of  the  American 
oil,  only  seventeen  per  cent,  is  obtained  on  distillation  of  the  crude 
turpentine  balsam;  of  the  French,  as  much  as  twenty-five  per  cent,  of 
oil  may  be  obtained;  and  of  the  Russian,  thirty-two  per  cent.  The 
essential  composition  of  all  three  of  these  oils,  when  rectified,  is  C10H16, 
but  distinct  hydrocarbons,  differing  in  physical  if  not  in  chemical 
characters,  are  considered  to  be  present  in  each  of  the  three  oils.  Thus 
the  terpene,  C10H16,  of  French  oil  of  turpentine  is  laevo-rotatory,  and  is 
known  as  Icevo-pinene,  while  that  of  the  American  oil  is  dextro-rotatory, 
and  is  known  as  dextro-pinene.  Otherwise  they  are  practically  identical 
in  properties.  Russian  oil  of  turpentine  consists  mainly  of  a  hydrocar- 
bon, sylvestrene,  which  boils  some  sixteen  to  twenty  degrees  Centigrade 
higher  than  the  others,  and  shows  some  other  minor  differences.  The 
commercial  oil  of  turpentine  is  a  colorless,  very  mobile,  highly  refracting 
liquid,  of  pleasant  odor  when  freshly  rectified,  but  becoming  disagree- 
able by  exposure  to  the  air,  as  it  absorbs  oxygen  and  becomes  resinous. 
It  is  almost  wholly  insoluble  in  water,  glycerine,  and  dilute  alkaline 
and  acid  solutions.  It  is  soluble  in  absolute  alcohol,  ether,  carbon  disul- 
phide,  benzene,  petroleum  spirit,  fixed  and  essential  oils.  It  is  itself  a 
solvent  for  sulphur,  phosphorus,  resins,  fats,  waxes,  caoutchouc,  etc. 


106          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

Within  recent  years  a  product  known  as  "wood  turpentine  "  has 
been  obtained  extensively  through  the  Southern  United  States  by  dis- 
tilling pine  wood  stumps  and  logs  with  steam.  While  resembling  the 
genuine  spirits  of  turpentine,  it  is  inferior  in  some  respects,  as  it  is  of 
different  constitution  in  part. 

Turpentine  yields  a  number  of  interesting  and  medicinally  important 
derivatives  under  the  influence  of  different  reagents.  Thus,  by  the  action 
of  hydrochloric  acid  gas  is  formed  pinene  hydrochloride,  C10H17C1, 
known  as  "artificial  camphor."  When  turpentine  oil  stands  in  contact 
with  water,  especially  in  the  presence  of  nitric  acid  and  alcohol,  it 
unites  with  three  molecules  of  water  to  form  a  hydrate,  C10H18(OH)2 
-f-  H20,  known  as  terpin  hydrate.  When  the  anhydrous  terpin,  C10H18 
(OH) 2,  is  distilled  with  dilute  sulphuric  acid  it  loses  a  molecule  of 
water  and  yields  terpineol,  C10H17('OH),  an  oil  of  hyacinthine  odor 
which  is  used  in  medicine.  When  sulphuric  acid  is  allowed  to  stand 
in  contact  with  oil  of  turpentine  and  the  mixture  after  a  day's  standing 
is  heated  to  boiling,  the  oil  is  changed  into  an  optically  inactive  mixture 
of  terpenes,  known  as  terebene,  'which  boils  at  156°-160°. 

Camphor. — This  is  one  of  the  most  important  of  the  oxidized  prin- 
ciples which  were  referred  to  as  accompanying  the  hydrocarbons  in  the 
crude  essential  oils.  While  the  name  is  frequently  used  to  designate  a 
class  of  compounds,  it  is  commercially  restricted  to  the  laurel  camphor, 
C10H160,  which  is  obtained  from  the  wood  of  the  Japan  camphor-tree 
(Camphora  officinarum)  by  distillation  with  water  and  after  purifica- 
tion with  sublimation.  It  forms  a  colorless,  translucent,  tough,  fibrous 
mass,  but  may  be  obtained  crystallized  in  prisms.  It  has  a  peculiar, 
fragrant  odor  and  burning  taste.  It  melts  at  347°  F.  (175°  C.),  and 
boils  at  399.2°  F.  (204°  C.).  It  is  nearly  insoluble  in  water,  but 
readily  soluble  in  alcohol,  ether,  acetone,  carbon  disulphide,  chloroform, 
and  oils. 

Camphor  has  also  been  obtained  on  a  commercial  scale  within  a  few 
years  from  oil  of  turpentine.  By  the  action  of  anhydrous  oxalic  acid 
upon  the  turpentine  is  formed  pinyl  oxalate  and  pinyl  formate.  By 
distillation  with  steam  in  the  presence  of  an  alkali,  the  pinyl  oxalate  is 
converted  into  camphor,  while  the  formate  is  changed  into  borneol.  The 
white  pulverulent  mixture  of  the  two  is  at  once  submitted  to  oxidation 
to  change  the  borneol  into  camphor.  The  yield  in  camphor  is  at  present 
from  twenty  to  thirty  per  cent,  of  the  turpentine  used. 

Borneol  (or  Borneo  camphor),  cineol  (or  eucalyptol),  linalool,  and 
geraniol  are  camphors  with  the  formula  C10H18O.  They  occur  either 
free  or  in  the  form  of  esters  in  many  of  the  essential  oils. 

Menthol,  C10H200,  is  a  white,  camphor-like  body  found  in  pepper- 
mint oil,  from  which  it  may  be  chilled  out.  It  is  largely  used  in  medi- 
cine and  pharmacy. 

Thymol,  C10H14O,  found  in  a  number  of  essential  oils,  is  a  solid 
phenol. 

2.  RESINS. — The  resins  are  products  of  the  oxidation  of  the  terpenes, 
and  either  accompany  them  in  the  crude  essential  oils  or  occur  as  exuda- 


RAW  MATERIALS.  107 

tions  from  trees  hardening  on  exposure  to  the  air.  The  chief  constit- 
uents of  the  resins  are  resin  esters,  resin  acids,  and  a  neutral  class  known 
as  resenes,  of  which  latter  little  is  known.  The  resin  esters  contain 
peculiar  alcohols,  the  resinols,  which  are  colorless,  and  resino-tannols, 
which  are  colored,  and  give  the  tannin  reaction.  The  classification  of 
resins  usually  adopted  at  present  is  into  (1)  true  resins,  (2)  gum 
resins,  and  (3)  oleo-resins  or  balsams.  The  true  resins  are  hard,  com- 
pact products  of  oxidation,  made  up  chiefly  of  what  are  termed  "resin 
acids,"  which,  admixed  with  fatty  acids,  are  capable  of  saponifying 
with  alkalies  and  yield  "rosin  soaps"  (see  p.  70)  ;  the  gum  resins  differ 
from  the  true  resins  only  in  containing  some  gum  capable  of  softening 
in  water;  and  the  oleo-resins  include  the  mixtures  of  essential  oil  and 
resin  of  whatever  consistency  and  the  mixtures  of  benzoic  and  cinnamic 
acid  and  salts  of  these  acids.  This  last  is  obviously  much  the  largest  of 
the  three.  To  the  first  class  belong  the  hard  resins,  which  serve  for  the 
manufacture  of  varnishes,  such  as  copal,  dammar,  mastic,  sandarach, 
dragon's  blood,  gum  lac,  and  amber;  to  the  second  class,  olibanum  or 
frankincense,  myrrh,  ammoniacum,  asafoetida,  galbanum,  and  traga- 
canth ;  and  to  the  third  class,  crude  turpentine,  benzoin,  storax,  copaiba, 
Peru  and  Tolu  balsams.  Brief  mention  will  be  made  of  a  few  of  the 
commercially  more  important. 

Amber  is  a  fossil  resin  found  in  detached  pieces  on  the  sea-coast, 
and  particularly  in  the  blue  earth  along  the  Baltic  coast  of  Prussia,  be- 
tween Konigsberg  and  Memel.  Its  applications  are  chiefly  as  an  article 
for  the  manufacture  of  mouth-pieces  of  pipes  and  cigar-holders  and  for 
beads,  for  the  preparation  of  a  superior  varnish,  and  for  the  production 
of  amber  oil  and  succinic  acid. 

Gum  Arabic. — This  is  included  among  gum  resins  because  an  exuda- 
tion analogous  to  other  resins,  but  is  almost  wholly  a  gum,  soluble  in 
water,  and  closely  related  chemically  to  the  starch  group.  (See  p.  185.) 
It  is  yielded  by  the  different  species  of  Acacia,  and,  at  present,  comes 
chiefly  from  Central  and  North  Africa,  by  the  way  of  Egypt,  Senegal, 
and  the  Red  Sea.  It  varies  greatly  in  purity  and  color,  and  is  used, 
because  of  its  mucilaginous  character,  for  a  multitude  of  applications, 
as  in  medicine,  confectionery,  preparation  of  textile  fabrics,  manufac- 
ture of  inks,  etc. 

Copal  and  Anime. — These  terms  include  a  number  of  related  resins, 
which  are  of  both  fossil  and  recent  origin.  The  Zanzibar  copal  or  anime 
is  chiefly  fossil,  and  is  dug  out  of  the  soil  by  the  natives  for  some  dis- 
tance along  the  southeastern  coast  of  Africa.  Some  freshly-exuded 
copal  resin  is  also  gathered  here.  On  the  west  coast  of  Africa,  for  a 
distance  of  seven  hundred  miles,  copal  resin  is  also  dug  as  a  fossil. 
When  of  good  quality  it  is  too  hard  to  be  scratched  by  the  nail,  has  a 
conchoidal  fracture,  and  a  specific  gravity  ranging  from  1.059  to  1.080. 
Unlike  others,  the  copal  resins  are  soluble  with  difficulty  in  alcohol  and 
essential  oils,  and  this  property,  combined  with  their  extreme  hardness, 
renders  them  very  valuable  for  making  varnishes. 

Dammar  is  obtained  from  the  Dammara  orientalis,  a  coniferous  tree, 


108          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

indigenous  in  the  East  Indies  and  Moluccas,  and  also  from  Dammara 
australis,  in  New  Zealand.  The  two  varieties  are  known  as  East  Indian 
and  Australian  dammar,  the  latter  being  also  known  as  Kauri  resin. 
The  former  is  that  commonly  met  with  in  commerce  under  the  simple 
name  of  dammar.  The  resin  occurs  in  masses,  coated  on  the  exterior 
with  white  powder  from  mutual  attrition,  while  the  interior  is  pale 
amber-colored  and  transparent.  It  is  scratched  by  copal,  but  is  harder 
than  rosin.  The  resin  splits  and  cracks  at  the  temperature  of  the  hand. 
The  Kauri  variety  is  chiefly  fossil  in  its  origin.  The  dammar  is  exten- 
sively used  in  the  manufacture  of  varnishes. 

Lac  is  a  resinous  incrustation  produced  on  the  bark  of  the  twigs  and 
branches  of  various  tropical  trees,  by  the  puncture  of  the  female  "lac 
insect  "  (Coccus  lacca).  This  crude  exudation  constitutes  the  stick-lac 
of  commerce.  Shell-lac  or  shellac  is  prepared  by  spreading  the  resin  into 
thin  plates  after  being  melted  and  strained.  In  the  preparation  of  the 
shellac,  the  resin  is  freed  from  the  coloring  matter,  which  is  formed 
into  cakes,  and  is  known  as  ' '  lac-dye. "  ' '  Button-lac  ' '  differs  from 
shellac  only  in  form.  Instead  of  being  drawn  over  a  cylinder,  the  melted 
lac  is  allowed  to  fall  upon  a  flat  surface,  and  assumes  the  shape  of  large 
cakes  about  three  inches  in  diameter  and  one-sixth  inch  thick.  Bleached 
lac  is  prepared  by  dissolving  lac  in  a  boiling  lye  of  pearl-ash  or  caustic- 
potash,  filtering  and  passing  chlorine  through  the  solution  until  all  the 
lac  is  precipitated.  This  is  then  collected,  well  washed,  and  pulled  in 
hot  water,  and  finally  twisted  into  sticks  and  thrown  into  cold  water  to 
harden. 

Seed-lac  is  the  residue  obtained  after  dissolving  out  most  of  the  color- 
ing matter  contained  in  the  resin.  The  common  shellac  is  used  in  var- 
nishes, lacquers,  and  sealing-wax ;  the  bleached  lac  in  pale  varnishes  and 
light-colored  sealing-wax. 

Mastic  is  the  resin  flowing  from  the  incised  bark  of  the  Pistacia 
lentiscus,  and  comes  exclusively  from  the  Island  of  Chios,  in  the  Medi- 
terranean. It  comes  into  commerce  in  pale,  yellowish,  transparent  tears, 
which  are  brittle,  with  conchoidal  fracture,  balsamic  odor,  and  softens 
between  the  teeth.  It  is  soluble  in  alcohol,  oil  of  turpetine,  and  acetone. 
It  is  used  in  varnish-making. 

Colophony  Resin  (rosin)  is  the  solid  residue  left  on  distilling  off  the 
volatile  oil  from  the  crude  turpentine.  The  resins  from  the  Bordeaux 
turpentine  and  that  from  the  American  turpentine  are  substantially 
identical.  Eosin  is  a  brittle,  tasteless,  very  friable  solid,  of  smooth, 
shining  fracture,  specific  gravity  about  1.08.  It  softens  at  80°  C.  (176° 
F.),  and  fuses  completely  to  a  limpid  yellow  liquid  at  135°  C.  (275°  F.). 

It  is  insoluble  in  water,  difficultly  soluble  in  alcohol,  but  freely  sol- 
uble in  ether,  acetone,  benzene,  and  fatty  oils.  With  boiling  alkalies  it 
takes  up  water  to  form  abietic  acid,  and  then  unites  with  the  alkali  to 
form  a  rosin  soap.  (See  p.  70.) 

3.  CAOUTCHOUC  (India-rubber). — This  is  the  chief  substance  con- 
tained in  the  milky  juice  which  exudes  when  a  number  of  tropical  trees 
belonging  to  the  natural  orders  Euphorbiacece,  Artocarpacece,  and  Apo- 


RAW  MATERIALS.  109 

cynaceoB  are  cut.  This  juice  is  a  vegetable  emulsion,  the  caoutchouc  be- 
ing suspended  in  it  in  the  form  of  minute  transparent  globules.  The 
emulsion  is  easily  coagulated,  and  the  caoutchouc  caused  to  separate 
by  the  addition  of  alum,  salt  solutions,  and  other  means. 

Caoutchouc  belongs  in  the  same  general  category  as  the  essential  oils, 
as  its  chief  constituent  is  polyprene  (C5H8)n.  This  is  a  polymer  of  iso- 
prene  (C3H8),  which  latter  along  with  dipentene  or  caoutchene  (C10H16) 
is  obtained  when  caoutchouc  is  destructively  distilled. 

The  different  species  of  rubber-trees  are  cultivated  in  Mexico,  South 
America,  and  the  West  Indies,  in  the  East  Indies,  Borneo,  Sumatra,  and 
the  African  coast. 

The  commercial  varieties  of  caoutchouc  may  be  grouped  under  four 
heads,  the  relative  value  of  which  accords  with  the  order  in  which  they 
are  placed:  South  American:  Para,  Ceara,  Carthagena,  Guayaquil;  Cen- 
tral American:  West  Indian,  Guatemala;  African:  Madagascar,  Mozam- 
bique, West  African;  Asiatic:  Assam,  Borneo,  Rangoon,  Singapore, 
Penang,  and  Java.  The  Para  rubber  (from  the  Hevea  Brasiliensis  or 
Siphonia  elastica)  is  the  best  of  the  many  varieties,  and  commands  the 
highest  price. 

Caoutchouc,  when  pure,  is  nearly  white,  but  the  commercial  varieties 
are  discolored  by  smoke  in  the  drying  of  the  freshly-exuded  juice  in  the 
methods  usually  followed.  At  ordinary  temperatures  caoutchouc  is  soft, 
elastic,  and  so  glutinous  that  two  freshly-cut  surfaces  pressed  strongly 
together  will  permanently  adhere.  At  low  temperatures  it  is  harder,  is 
less  elastic  and  adhesive,  while,  on  heating  it,  the  elastic  property  dis- 
appears also,  and  it  becomes  perfectly  soft  and  can  be  kneaded.  In 
water  caoutchouc  swells  up  without  dissolving;  in  ether,  petroleum- 
naphtha,  benzene,  carbon  disulphide,  oil  of  turpentine,  rosin  oil,  and  oils 
gotten  by  the  dry  distillation  of  the  rubber  itself,  the  caoutchouc  swells 
up  rapidly,  and  after  a  time  dissolves  to  a  greater  or  less  degree.  The 
best  solvents  are  carbon  disulphide,  chloroform,  and  carbon  tetrachlo- 
ride,  and  Payen  recommends  carbon  disulphide,  to  which  five  per  cent, 
of  absolute  alcohol  has  been  added,  as  excellent.  Caoutchouc  is  quite 
indifferent  to  most  chemical  reagents,  but  is  attacked  by  strong  nitric 
and  sulphuric  acids.  Fatty  matters  present  in  the  solvents  used  seem  to 
have  a  deleterious  action  upon  the  caoutchouc,  causing  it  to  become  first 
soft  and  afterwards  hard  and  brittle.  Caoutchouc  softens  at  120°  C., 
melts  at  about  150°  C.,  and  decomposes  at  200°  C. 

Highly  purified  rubber  has  a  specific  gravity  of  0.911  at  17°  C.,  and 
the  technically  pure  substance  from  .915  to  0.931.  On  exposure  to  air 
and  light,  rubber  is  oxidized  to  a  hard  resin  somewhat  resembling  shel- 
lac. Hence  articles  of  caoutchouc  should  preferably  be  preserved  in  the 
dark  in  well-closed  containers.  If  they  become  hard,  their  elasticity  may 
be  restored  by  exposing  them  to  the  vapor  of  carbon  disulphide  and  sub- 
sequently of  petroleum. 

Chlorine  and  bromine  act  energetically  on  caoutchouc  to  form  both 
addition  and  substitution  compounds.  Strong  sulphuric  acid  chars  and 
oxidizes  caoutchouc  on  heating,  and  nitric  acid  converts  it  gradually  on 


110          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

boiling  into  oxalic,  camphoric,  and  camphoronic  acids.  Ozone  also  attacks 
it  readily,  producing  a  viscid  oil.  Nitrogen  tetroxide  as  dry  gas  passing 
into  caoutchouc  in  benzene  solution  forms  a  compound  C10H16N204, 
which  is  readily  soluble  in  acetone  but  almost  insoluble  in  methyl  and 
ethyl  alcohols,  ether,  chloroform,  and  carbon  disulphide.  This  reaction 
is  used,  therefore,  for  the  determination  of  real  caoutchouc  in  manu- 
factured rubber. 

4.  GUTTA-PERCHA  AND  SIMILAR  PRODUCTS. — Gutta-percha  is  obtained 
from  the  milky  juice  of  different  trees  of  the  genus  Isonandra,  belong- 
ing to  the  natural  order  Sapotacecc.  By  the  coagulation  of  the  collected 
juice  the  gutta-percha  globules  mass  together  and  can  be  kneaded  into 
lumps.  The' localities  in  which  the  gutta-percha  is  cultivated  are  Borneo, 
Sumatra,  and  the  Malayan  Archipelago.  It  comes  into  commerce  in 
irregularly-  and  fancifully-formed  blocks.  It  forms  a  fibrous  mass,  vary- 
ing in  color  from  nearly  white  to  reddish  or  brownish,  looking  some- 
thing like  leather  clippings  cemented  together,  and  has  a  specific  gravity 
of  .979.  At  ordinary  temperatures  it  is  hard  and  somewhat  elastic,  at 
25°  C.  (77°  F.)  it  becomes  soft,  and  at  50°  C.  (122°  F.)  it  can  be 
kneaded  or  rolled  out  into  plates.  Between  55°  C.  and  60°  C.  it  is  so 
thoroughly  plastic  as  to  be  drawn  into  tubes,  thread,  plates,  and  at  120° 
C.  (248°  F.)  it  melts.  Its  elasticity  seems  distinctly  greater  in  the 
direction  of  its  fibre  than  in  an  opposite  one,  while  caoutchouc  is  equally 
elastic  in  all  directions.  Gutta-percha  is  a  poorer  conductor  of  elec- 
tricity than  caoutchouc,  and  hence  its  extensive  use  in  insulating  wires 
and  cables.  Its  power  of  softening  at  45°  C.  is  partly  overcome  by  the 
process  of  vulcanization  or  union  with  sulphur.  Chemically,  gutta- 
percha  seems  to  be  composed,  like  caoutchouc,  of  a  hydrocarbon 
(C10H10)n,  but  is  always  accompanied  by  a  certain  amount  of  oxidation 
products.  Payen  found  that  the  crude  gutta-percha,  after  thorough 
exhaustion  with  alcohol,  left  seventy-eight  to  eighty-two  per  cent,  of  a 
pure  hydrocarbon,  that  he  termed  gutta,  which,  at  from  15°  C.  to  30°  C. 
(59°  to  86°  F.),  was  tenacious  and  ductile,  but  not  very  plastic. 

Gutta-percha  dissolves  in  all  the  solvents  of  India  rubber.  It  is  also 
attacked  readily  by  ozone,  but  not  at  all  by  hydrofluoric  acid,  which  is, 
therefore,  often  kept  as  a  reagent  in  bottles  of  gutta-percha.  Nitrous 
acid  gas  N203  acts  upon  it  as  upon  caoutchouc,  giving  rise  to  a  nitrosite 
C10H16N307. 

Batata  is  the  dried,  milky  juice  of  the  bully-tree  (Sapota  Milleri), 
which  flourishes  in  Guiana.  The  balata  is  obtained  from  the  juice  in  a 
manner  similar  to  gutta-percha.  In  its  properties  it  is  intermediate  to 
caoutchouc  and  gutta-percha;  it  is  more  plastic  and  readily  kneaded 
than  the  former  and  more  elastic  than  the  latter.  At  ordinary  tempera- 
tures it  is  compact  and  horny,  but  at  49°  C.  already  it  becomes  soft,  and 
can  be  shaped.  Towards  solvents  it  behaves  like  gutta-percha. 

Large  quantities  of  it  are  imported  from  Mexico,  under  the  name 
chicle,  into  the  United  States  and  used  in  the  manufacture  of  "chewing 
gum. ' ' 

It  is  used  chiefly  in  England  as  a  substitute  for  gutta-percha  and 


PROCESSES  OF  TREATMENT.  Ill 

caoutchouc,  and  is  also  used  as  an  addition  to  these.  Towards  chloride 
of  sulphur  and  metallic  sulphides  it  acts  like  caoutchouc  and  gutta- 
percha. 

5.  NATURAL  VARNISHES. — This  term  is  applied  to  a  class  of  natural 
products  which  are  resinous  exudations,  capable  of  direct  use  as  var- 
nishes or  lacquers.  The  most  important  are: 

(1)  Burmese  lacquer,  a  thick,  grayish  terebinthinous  liquid,  collected 
form  the  Melanorrhoea  usitatissima  of  Burmah.     It  dissolves  in  alcohol, 
turpentine  oil,  and  benzene,  assuming  greater  fluidity.     Locally,  it  is 
used  in  enormous  quantities  in  lacquering  furniture,  temples,  idols,  and 
varnishing  vessels  for  holding  liquids. 

(2)  Cingalese  and  Indian  lacquer,  a  black  varnish  obtained  in  Cey- 
lon and  India  from  Semicarpus  anarcardium,  and  in  Madras,  Bombay, 
and  Bengal,  from  Holigarua  longifolia.    It  forms  an  excellent  varnish, 
adhering  strongly  to  wood  and  metal. 

(3)  Japanese  and  Chinese  lacquer  is  derived  from  several  species  of 
RJius,  whose  fruits  form  the  Japan  wax  of  commerce.     (See  p.  59.)     The 
lacquer  exudes  as  a  milky  juice  from  the  trunk  of  the  tree.    On  exposure 
to  sunlight  or  when  warmed,  it  loses  its  moisture  and  becomes  a  brown 
oily  liquid  to  which  oils,  pigments,  etc.,  are  added  to  form  the  finished 
lacquer.     It  is  most  extensively  used  in  Japanese  and  Chinese  lacquer- 
work. 

n.  Processes  of  Treatment. 

1.  MANUFACTURE  OF  PERFUMES  AND  SIMILAR  PRODUCTS. — In  the  use 
of  essential  oils  or  mixtures  of  them,  as  the  basis  of  agreeable  smelling 
preparations  or  perfumes,  several  classes  of  preparations  may  be  dis- 
tinguished: (1)  Perfumed  waters  or  alcoholic  solutions  of  mixed  essen- 
tial oils;  (2)  odoriferous  extracts  or  alcoholic  extracts  from  fatty  acids 
charged  with  odors  by  ' ' enfleurage "  or  maceration;  and  (3)  pomades 
and  perfumed  soaps.  In  the  manufacture  of  the  first  class  of  prepara- 
tions, the  alcohol  to  be  used  must  be  free  from  fusel-oil  and  thoroughly 
deodorized.  The  essential  oils  may  be  in  part  dissolved  separately  in 
the  alcohol  or  added  together  to  the  proper  quantity  of  the  solvent  ac- 
cording to  the  nature  of  the  materials.  Long-continued  standing  of  the 
alcoholic  solutions  is  now  considered  sufficient  to  effect  a  thorough  amal- 
gamation and  development  of  the  desired  perfume,  and  distillation  is 
dispensed  with.  As  examples  of  such  perfumes  we  have  the  well-known 
cologne  waters  and  eau  de  mille  fleurs. 

The  odoriferous  extracts  are  gotten  by  treating  with  alcohol  the  fatty 
oils  and  fats  which  have  been  charged  with  the  perfumes  of  flowers  by 
the  "enfleurage"  process.  Glycerine,  soft  paraffin,  and  vaseline  have 
latterly  been  used  too  in  the  extraction  of  the  odors.  On  chilling  the 
alcohol  by  freezing  mixtures  or  other  means  to  — 18°  C.,  the  fat  is 
separated  out  and  gotten  rid  of. 

Pomades  are  made  from  fatty  oils,  the  basis  usually  being  oil  of 
almonds,  oil  of  ben,  or  olive  oil.  The  processes  for  preparing  these 


112          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

scented  fats  are  those  of  infusion  with  warm  fatty  oils  or  melted  fats 
at  a  temperature  of  about  65°  C.,  and  of  ' '  enfleurage, "  or  cold  perfum- 
ing, as  already  described. 

2.  MANUFACTURE  OP   VARNISHES. — Very  much  more   important,   in 
an  industrial  sense,  is  this  application  of  essential  oils  and  resins.    Under 

Fio.  31. 


the  name  varnish  is  generally  understood  either  a  solution  of  a  resin  or  a 
rapidly  resinifying  oil,  which,  when  applied  to  solid  bodies,  becomes  dry 
and  hard,  either  by  evaporation  of  the  solvent  OK  a  drying  and  oxidation 
of  the  same,  while  the  film  of  resin  left  behind  makes  a  hard,  glossy 
coating,  impervious  to  air  and  moisture.  Varnishes  may  be  of  three 
classes,  according  to  the  character  of  the  solvent  used  for  resin:  (1) 


PROCESSES  OF  TREATMENT. 


113 


Linseed-oil  varnishes,  in  which  boiled  linseed-oil  is  used;  (2)  spirit  var- 
nishes, in  which  alcohol  or  petroleum  spirit  is  used;  (3)  turpentine-oil 
varnishes. 

Linseed-oil  Varnishes. — Linseed  oil  itself,  as  a  drying  oil  (see  p.  54), 
is  capable  of  forming  a  varnish  without  the  addition  of  a  resin.  For 
the  preparation  of  varnish,  the  oil  must  first  be  boiled.  When  heated 
to  130°  C.  it  begins  to  boil,  but  the  heat  is  continued  until  it  shows  about 
260°  C.  (500°  F.),  which  temperature  should  not  be  much  exceeded. 
It  absorbs  oxygen  in  this  process  and  becomes  thick  and  glutinous.  The 
absorption  of  oxygen  and  the  thickeing  of  the  oil  are  much  accelerated 
by  the  use  of  driers  like  litharge,  manganese  dioxide,  lead  acetate,  man- 
ganese borate,  etc.  These  substances  act  as  "contact  substances,"  most 
probably  because  of  their  tendency  to  form  superoxides  which  then 
bring  about  the  rapid  oxidation  of  the  oil.  (See  p.  81.)  Boiling 
linseed  oil  over  free  fire,  as  it  is  generally  carried  on,  is  illustrated  in 
Fig.  31.  Care  should  be  taken  that  the  kettle  is  not  filled  so  full  as  to 

FIG.  32. 


allow  it  to  boil  over  when  strongly  heated.  The  lid  e,  ordinarily  raised, 
can  be  lowered  upon  it  if  the  escaping  decomposition  products  catch  fire. 
In  Fig.  32  is  shown  a  pair  of  kettles  arranged  for  boiling  the  linseed 
oil  by  steam.  Pressures  of  four  and  a  half  to  five  atmospheres  are  used 
for  the  steam  in  this  case,  and  a  temperature  of  132°  C.  (269.6°  F.), 
yielding  a  perfectly  clear,  light-colored  varnish.  When  boiled  so  as  to 
have  lost  one-twelfth  of  its  weight  it  yields  the  ordinary  boiled  oil  var- 
nish; if  heated  until  it  loses  one-sixth  of  its  weight  it  becomes  thicker 
and  yields  a  stiff  varnish,  which  is  used  as  the  basis  of  printers'  ink. 
(See  p.  115.)  The  specific  gravity  of  boiled  linseed  oil  of  good  quality 
varies  from  .940  to  .950,  and  on  ignition  it  leaves  a  mineral  residue 
of  from  .2  to  .4  per  cent.  Experiment  has  taught  that  oxidation  pro- 
ceeds the  more  rapidly  when  it  is  pushed  rapidly;  or,  in  other  words, 
in  order  to  change  linseed  oil  into  varnish  by  atmospheric  exposure,  it 
must  be  brought  to  boiling  as  rapidly  as  possible.  What  takes  place 
in  this  case  is  not  an  evaporation  simply,  but  a  decomposition  of  the 
linolein  (glyceride  of  linoleic  acid)  takes  place,  whereby  glycerine  sepa- 


114          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

rates,  and  a  portion  of  the  linoleic  acid  changes  into  linoleic  anhydride, 
C32H54O31,  an  elastic  and  caoutchouc-like  mass  (see  p.  122),  which  then 
dissolves  in  the  undecomposed  linseed  oil  and  gives  the  oil  its  valuable 
varnish-forming  and  drying  character.  Another  part  of  the  linoleic  acid, 
liberated  by  the  boiling,  absorbs  oxygen  and  changes  into  oxylinoleic 
acid,  C16H26O5,  which  at  first  is  of  turpentine-like  character,  while  all 
undecomposed  glyceride  of  linoleic  acid  dries  up  to  elastic  linoxyn, 
CggHg^On.  A  good  varnish,  therefore,  is  made  up  of  three  factors: 
(1)  Linoleic  anhydride,  (2)  oxylinoleic  acid,  and  (3)  linoxyn. 

These  views  of  Mulder  as  to  the  changes  which  occur  in  the  boiling 
of  linseed  oil  are  controverted  by  Bauer  and  Hazura,*  who  consider  that 
the  liquid  fatty  acids  of  linseed  oil  consist  of  eighty  per  cent,  of  linolenic 
and  isolinolenic  acids  (C18H.,0O2),  together  with  nearly  twenty  per  cent, 
of  linoleic  acid  (C18H3202),  and  small  quantities  of  oleic  acid  (C18H.!402). 
They  consider  Mulder's  oxylinoleic  acid  to  have  been  a  mixture,  and 
state  that  the  more  linolenic  acid  an  oil  contains,  the  more  quickly  it 
dries. 

The  pure  linseed-oil  varnish  so  prepared  may  then  serve  for  the  prep- 
aration of  what  are  termed  lacquers  or  solutions  of  resins  in  linseed-oil 
varnish,  thinned  out  ordinarily  with  turpentine  oil  or  benzine.  Of  the 
resins,  amber,  copal,  anime,  dammar,  and  asphalt  are  used  for  these 
lacquers.  In  order  to  prepare  these  varnishes,  the  resins,  amber,  copal, 
etc.,  are  fused  in  a  kettle  placed  over  a  coal-fire  in  such  a  way  that  it 
sinks  into  the  fire-chamber  but  a  slight  distance,  and  the  flame  can 
touch  the  bottom  of  the  kettle  only.  After  the  resin  has  fused,  the 
proper  amount  of  boiling  linseed-oil  varnish  is  added,  care  being  taken 
that  the  mixture  does  not  fill  the  kettle  to  more  than  two-thirds  at  the 
most,  and  the  contents  then  boiled  for  ten  minutes.  When  the  kettle 
has  cooled  down  to  about  140°  C.,  the  necessary  amount  of  turpentine 
oil  is  added. 

In  the  case  of  the  two  resins,  amber  and  copal,  something  more  than 
a  fusion  is  essential.  They  are  submitted  to  a  dry  distillation,  and 
only  after  they  have  given  off  from  ten  to  twenty  per  cent,  of  their 
weight  in  oily  distillation  products  does  the  residue  become  perfectly 
soluble.  A  form  of  still  in  which  this  distillation  of  resins  is  carried  out 
is  shown  in  Fig.  33.  The  copper  still  B,  which  is  heated  in  this  case 
over  the  direct  fire,  is  provided  with  mechanical  agitation,  R,  and  a 
tube,  A,  for  drawing  off  the  melted  residue.  This  tube  is  covered  where 
it  projects  through  the  fire  by  fire-brick  to  protect  it  from  the  flame. 
The  distillation  products  escape  through  D  and  are  condensed  by  the 
worm  K.  The  dry  distillation  of  copal  proceeds  best  at  a  temperature 
of  340°  to  360°  C.,  while  that  of  amber  requires  380°  to  400°  C.  If 
heated  higher  than  these  temperatures  the  resins  become  dark.  As  the 
melting-point  of  lead  is  334°  C.,  a  lead  bath  is  recommended  for  the 
copal  distillation. 

These  lacquers  are  the  hardest  and  most  durable  of  varnishes,  but 
they  dry  more  slowly  than  simple  linseed-oil  varnish. 

*  Zeit.  fur  Angew.  Chem.,  1888,  pp.  455-458. 


PROCESSES  OF  TREATMENT. 


115 


Spirit  varnishes  are  solutions  of  resins,  such  as  sandarac,  mastic, 
dammar,  gum-lac,  and  shellac,  in  alcohol,  although  this  is  sometimes 
replaced  by  other  solvents,  such  as  methyl  alcohol,  acetone,  and  petro- 
leum spirit.  The  spirit  varnishes  dry  rapidly,  leaving  a  brilliant  sur- 
face, but  are  more  apt  to  crack  and  peel  off  than  turpentine  varnishes. 
Turpentine  is  often  added  to  these  varnishes  to  diminish  this  brittleness. 
Among  the  most  important  varnishes  of  this  class  are  shellac  varnish,  of 
which  the  finest  grade  is  prepared  from  bleached  shellac  dissolved  in 
alcohol,  and  copal  varnish.  In  the  preparation  of  this  latter,  the  copal 
must  be  first  fused,  or  rather  submitted  to  dry  distillation  in  the  manner 
already  described.  (See  p.  114.)  The  fused  copal  residue  is  afterwards 
powdered,  mixed  with  sand  and  covered  with  strong  alcohol,  heated  to 
boiling  for  some  time  and  then  filtered.  The  addition  of  elemi  resin 
imparts  a  toughness  to  the  copal  varnish. 

Colored  spirit  varnishes  are  made  by  the  addition  of  alcoholic  extracts 
of  annatto,  dragon's  blood,  gamboge,  turmeric,  cochineal,  or  even  solu- 
tions of  the  different  coal-tar  colors. 

FIG.  33. 


Turpentine-oil  Varnishes. — These  are  prepared  in  the  same  way  as 
the  spirit  varnishes.  They  dry  more  slowly,  but  are  more  flexible  and 
durable.  The  most  important  are  copal  varnish  and  dammar  varnish. 
Turpentine  and  linseed  oil  are  frequently  used  jointly  in  the  prepara1 
tion  of  varnishes,  so  as  to  obtain  the  best  results.  Thus,  in  the  manu- 
facture of  copal  and  amber  varnishes,  described  before  (see  p.  114),  the 
relative  amounts  of  materials  are:  Ten  parts  of  copal  or  amber  (or  the 
residue  from  the  distillation  of  amber  oil),  twenty  to  thirty  parts  of 
linseed-oil  varnish,  and  twenty-five  to  thirty  parts  of  oil  of  turpentine. 

3.  MANUFACTURE  OF  PRINTER'S  INK. — Printer's  ink,  of  whatever 
grade,  whether  for  newspaper  print,  for  book,  lithographic,  or  copper- 
plate printing,  is  a  very  stiff,  rapidly-drying  linseed-oil  varnish,  to 
which  has  been  added  lamp-black  or  charcoal  in  the  finest  state  of  divi- 
sion. For  its  preparation,  linseed,  poppy,  or  nut  oil  is  heated  in  copper 
vessels,  over  a  free  fire  to  a  temperature  beyond  the  boiling-point,  so 
that  inflammable  vapors  are  given  off.  These  are  frequently  ignited, 
or,  as  is  now  preferred,  they  may  be  allowed  to  escape  into  a  draught 
chimney.  The  heating  is  continued  until  the  oil  becomes  quite  thick 


116          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

and  a  film  forms  on  the  surface,  which  causes  it  to  swell  up  with  escap- 
ing bubbles  of  vapor.  A  sample  taken  out  and  tested  between  the 
fingers  should  draw  out  in  long  filaments.  In  this  condition,  with  the 
addition  of  about  sixteen  per  cent,  of  lamp-black,  the  varnish  will  dry 
very  easily  and  rapidly.  If  the  varnish  has  not  been  boiled  long  enough, 
the  printed  characters  will  run  together  and  oil  will  be  absorbed  in  the 
paper  fibre,  so  that  the  printed  letters  will  show  a  yellowish  border. 

For  the  ink  to  be  used  in  book-printing,  an  addition  of  soap  is  abso- 
lutely necessary;  it  allows  the  inked  type  to  be  withdrawn  from  the 
moist  paper  clear  and  sharp  without  any  adhering  or  smearing.  The 
finer  the  printed  work  required  the  stiffer  and  more  thoroughly  boiled 
the  varnish  must  be,  so  that  for  copperplate  and  lithographic  inks  a 
much  stiffer  ink  is  needed  than  that  which  is  used  for  newspaper  or  even 
book  printing.  The  expensive  linseed  oil  is  frequently  replaced  by 
hemp-seed,  poppy,  or  nut  oil.  In  order  to  obviate  the  necessity  of  boil- 
ing the  oil  down  so  thick,  rosin  is  sometimes  added  to  the  varnish.  Thus, 
to  one  hundred  and  twenty  parts  of  linseed  oil  forty  to  fifty  parts  of 
rosin  are  added  and  twelve  to  fourteen  parts  of  soap.  Rosin  oil  is  also 
used  in  place  of  a  part  of  the  linseed  oil ;  indeed,  cheap  printing  ink 
can  be  made  composed  of  rosin  oil,  rosin  soap,  and  lamp-black  alone, 
without  the  addition  of  linseed  oil  at  all. 

Colored  printing  inks  are  obtained  by  adding  to  the  boiled-oil  var- 
nish vermilion,  Prussian  blue,  indigo,  and  other  colors. 

4.  MANUFACTURE  OF  OIL-CLOTH,  LINOLEUM,  ETC. — In  the  manufac- 
ture of  oil-cloths,  the  basis  is  a  coarse  canvas,  of  jute  or  cotton  stuff 
usually,  which  is  coated  with  repeated  layers  of  linseed  oil,  which  has 
been  previously  boiled  sufficiently  with  litharge,  and  to  which  the 
coloring  matter  has  been  added,  or,  in  other  words,  a  linseed-oil  paint. 
Before  putting  on  the  coatings  of  paint,  the  canvas  is  primed  with  a 
coating  of  size.  The  object  of  this  is  not  only  to  give  a  body  to  the 
cloth,  but  also  to  protect  the  fibre  from  the  injurious  action  of  the  acid 
products  generated  during  the  oxidation  of  the  linseed  oil  which  is 
subsequently  applied.  Cloth  which  is  covered  with  paint  without  a 
protective  coating  of  size  soon  becomes  rotten  and  brittle.  Both  sides 
of  the  canvas  are  painted  in  this  way.  After  thorough  drying  of  this 
layer  a  second  coat  is  applied  to  both  sides.  This  suffices  for  the  back 
of  the  oil-cloth.  The  painting  of  the  face  side  is  continued  until  it  is 
sufficiently  built  up  for  the  printing  of  the  pattern.  Most  of  the  print- 
ing is  hand-printing  done  by  blocks,  the  number  of  which  correspond 
to  the  number  of  colors  to  be  used. 

Linoleum  is  a  name  often  given  to  a  form  of  oil-cloth  in  which 
powdered  cork  and  pigment  are  incorporated  with  a  thoroughly  oxidized 
linseed  oil,  which  has  been  brought  to  the  condition  of  a  relatively  dry 
sponge.  A  pattern  may  then  be  printed  on  and  a  transparent  varnish 

to  cover  all. 

The  oxidized  oil  used  in  linoleum  manufacture  has  sometimes  both 
rosin  and  kauri  gum  added  to  it  to  give  it  toughness.  The  proportions 
for  ordinary  linoleum  are:  Oxidized  oil,  eight  and  one-half  hundred- 


PROCESSES  OF  TREATMENT.  117 

weight;  rosin,  one  hundredweight;  kauri  gum,  one-half  hundredweight. 
A  variety  of  linoleum  containing  wood  fibre  instead  of  ground  cork  has 
of  late  years  been  introduced  as  a  substitute  for  wall-papering  under 
the  name  of  ' '  lincrusta. " 

5.  PROCESSES  OF  TREATMENT  OF  CAOUTCHOUC  AND  GUTTA-PERCHA. — 
The  crude  rubber  as  brought  into  commerce  is  quite  impure  from  acci- 
dental causes,  and,  in  many  cases,  from  intentional  adulteration.  It, 
therefore,  must  undergo  a  thorough  mechanical  cleaning  before  being 
submitted  to  any  chemical  treatment.  It  is  first  boiled  with  water  (to 
which  a  little  slaked  lime  is  advantageously  added)  until  thoroughly 
softened,  then  cut  into  slices  and  passed  repeatedly  between  grooved 
rollers,  known  as  washing  rollers,  while  a  stream  of  cold  water  flows 
over  it.  This  crushes  and  carries  away  any  solid  impurities  as  well  as 
those  which  are  soluble.  Under  this  treatment  Para  rubber  loses  from 
twelve  to  fifteen  per  cent,  of  its  weight;  the  African  variety,  twenty- 
five  to  thirty-three  per  cent.  After  this  washing,  the  rubber  is  carefully 
and  thoroughly  dried.  Neglect  of  this  frequently  causes  the  wares 
when  subsequently  vulcanized  to  appear  spongy.  The  caoutchouc  is 
now  to  be  worked  over  and  agglomerated  thoroughly,  which  is  done 
either  by  passing  it  repeatedly  between  rollers  heated  to  70°  or  80°  C., 
or  by  the  aid  of  the  so-called  masticating  or  kneading  machine,  which 
consists  of  a  hollow  cylinder  within  which  revolves  another  cylinder 
with  a  fluted  or  corrugated  surface.  The  rubber  being  placed  in  the 
annular  space  between  the  two  cylinders,  the  inner  one  is  made  to 
revolve,  whereby  the  mass  is  worked  over  and  over  and  thoroughly 
kneaded.  The  rubber  is  now  to  be  mixed  with  the  sulphur  needed  for 
its  vulcanization  and  with  whatever  coloring  or  weighting  materials 
are  to  be  used.  This  mixing  is  effected  by  the  aid  of  horizontal  rollers 
heated  internally  with  steam,  and  so  geared  as  to  move  in  contrary 
directions  at  unequal  speed.  This  mixed  rubber  so  obtained  can  readily 
be  softened  by  heat,  and  can  now  be  shaped,  moulded,  or  rolled  into 
any  desired  shape,  and  then  submitted  to  the  heat  necessary  for  vul- 
canization. 

The  vulcanization  of  rubber  consists  in  effecting  a  combination  of 
the  caoutchouc  with  sulphur  or  sulphides  whereby  the  behavior  of  the 
caoutchouc  towards  heat  and  towards  solvents  is  changed.  Its  value 
for  technical  purposes  is  greatly  increased  by  this  change. 

Two  methods  of  vulcanization  are  to  be  noted:  (1)  the  vulcanizing 
by  mixing  with  sulphur  or  metallic  sulphides  and  heating  to  125°  to 
140°  C. ;  (2)  the  cold  vulcanization  process  of  Alexander  Parkes,  con- 
sisting of  immersing  the  rubber  articles  in  a  solution  of  chloride  of 
sulphur  in  carbon  disulphide  or  benzene.  The  latter  process  is  only 
used  for  small  articles  or  those  consisting  of  thin  layers  of  caoutchouc, 
as  the  action  of  the  chloride  of  sulphur,  even  in  the  two  and  one-half 
per  cent,  solution  usually  employed,  is  very  rapid,  while  at  the  same 
time  it  is  superficial,  so  that  it  is  difficult  to  control  the  action  properly. 
In  vulcanizing  by  the  first  process,  that  of  "burning,"  as  it  is  termed, 
the  crude  caoutchouc  is  mixed  with  varying  amounts  of  sulphur;  for 


118 


INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 


soft  rubber  goods  with  about  ten  per  cent.,  for  hard  rubber  or  vulcanite 
with  thirty  to  thirty-five  per  cent.,  of  sulphur.  Instead  of  sulphur, 
metallic  sulphides  are  used,  such  as  alkaline  sulphides,  sulphide  of  lead, 
and  sulphide  of  antimony.  For  red  rubber  goods  the  latter  is  always 
used.  For  soft  rubber  articles  the  proper  temperature  for  vulcaniza- 
tion lies  between  120°  and  136°  C. ;  for  hard  rubber,  from  140°  to 
142°  C.  In  vulcanizing,  only  a  part  of  the  sulphur  is  chemically  com- 
bined, a  part  remaining  mechanically  mixed.  This  can  be  largely 
removed  by  boiling  the  finished  articles  in  a  solution  of  caustic  soda. 
Both  air-baths  and  steam-baths  are  in  use  for  heating,  the  latter  at 
present  in  the  majority  of  cases.  A  form  of  vulcanizing  vessel  for 
smaller  articles  is  shown  in  Fig.  34.  The  lid  can  be  removed  by  the 
mechanism  shown  at  a,  and  the  manometer  ra  shows  the  pressure  exist- 
ing in  the  vulcanizer  A.  This  final  heating  which  effects  the  change 

FIG.  34. 


in  the  rubber  is  frequently  called  the  "curing  "  of  the  rubber.  Vul- 
canized rubber  goods  can  be  manufactured  in  the  greatest  variety  of 
shapes  and  for  a  multitude  of  uses,  the  rubber  being  in  almost  all  cases 
"cured  "  after  the  shaping. 

In  the  manufacture  of  hard-rubber  articles,  the  East  Indian,  and 
specially  the  Java  and  Borneo,  caoutchouc  is  used,  the  Para  rubber 
being  too  expensive,  and  besides  not  so  well  adapted.  While  in  the 
manufacture  of  soft  rubber  the  burning  or  curing  was  the  last  process, 
following  the  shaping  of  the  articles,  in  the  manufacture  of  the  hard 
rubber  the  curing  is  generally  done  before  the  articles  are  finally  shaped. 
Only  in  the  manufacture  of  moulded  goods  is  the  curing  done  last. 
Gutta-percha,  balata,  and  colophony  resin  are  often  added  to  modify  the 
hardness  and  elasticity,  while  a  large  number  of  mineral  substances, 
such  as  chalk,  gypsum,  calcined  magnesia,  zinc  oxide,  asphalt,  etc.,  are 
added  chiefly  for  cheapening  purposes.  A  kind  of  vulcanite  or  hard 


PRODUCTS.  119 

rubber  which  contains  a  very  large  proportion  of  vermilion  is  used, 
under  the  name  of  dental  rubber,  for  making  artificial  gums. 

The  working  over  of  scrap  rubber  has  in  recent  years  assumed  much 
importance.  Although  scraps  of  raw  caoutchouc  can  easily  be  kneaded 
or  rolled  together,  vulcanized  rubber  cannot  be.  The  insolubility  of  the 
vulcanized  rubber  in  ordinary  solvents  presents  another  difficulty. 
Although  the  problem  is  not  yet  solved,  numerous  proposals  have  been 
made.  These  all  involve  one  of  three  lines  of  treatment:  (1)  mechan- 
ical subdivision  of  the  scrap  and  the  adding  of  the  powder  so  obtained 
to  fresh  caoutchouc;  (2)  heating  the  vulcanized  scrap  to  fusion  and 
use  of  the  pitchy  mass  so  obtained  as  mixing  material;  (3)  partial  de- 
sulphurization  of  the  caoutchouc  by  treatment  with  acid  or  alkali  under 
pressure,  washing  and  sheeting  of  the  reclaimed  rubber. 

Treatment  of  Gutta-percha. — This  is  quite  similar  to  that  described 
under  caoutchouc.  The  crude  gutta-percha  must  be  thoroughly  washed 
and  freed  from  dirt  and  mechanically  mixed  impurities.  It  is  then  cut 
or  torn  into  fine  shreds,  which  are,  after  washing,  heated  so  as  to  ball 
them  together.  It  is  now  kneaded  and  compacted  so  as  to  drive  out 
the  air-bubbles. 

Gutta-percha  is  used  both  in  the  vulcanized  and  unvulcanized  con- 
dition. The  vulcanization  is  carried  out,  as  in  the  case  of  caoutchouc, 
by  the  addition  of  sulphur  and  curing.  The  amount  of  sulphur  varies 
from  six  to  ten  per  cent.,  and  the  temperature  for  vulcanization  lies 
between  135°  and  150°  C.  The  gutta-percha  scraps  are  worked  up 
generally  by  desulphurizing  the  vulcanized  material  by  boiling  for  five 
to  six  hours  in  a  six  to  eight  per  cent,  solution  of  caustic  soda,  washing, 
drying,  dissolving  in  carbon  disulphide,  benzene,  or  turpentine,  and 
then  distilling  off  the  solvent. 

HI.  Products. 

1.  PERFUMES. — The  general  character  of  the  several  classes  of  per- 
fumes has  already  been  indicated  in  the  previous  section,   while  the 
products  are  so  extremely  numerous  and  special  in  character  that  any 
attempt  at  detail  description  would  be  beyond  the  province  of  this  work. 

2.  VARNISHES. — We  have  to  note  here  both  the  natural  varnishes, 
already  referred  to    (see  p.   Ill),  and  manufactured  varnishes.     The 
classification  of  manufactured  varnishes,  already  given,  was:     (1)  Lin- 
seed-oil varnishes,  including  both  plain  boiled  linseed-oil  varnish  and 
solutions  of  resins  in  the  boiled  oil,  or  lacquers,  as  they  are  often  called ; 
(2)   spirit  varnishes,  including  not  only  alcoholic  solutions  of  resins, 
but  solutions  of  the  latter  in  benzol,  petroleum  spirit,  wood-naphtha,  and 
other  volatile  liquids,  and  (3)  turpentine-oil  varnishes. 

Natural  Varnishes. — With  regard  to  the  Burmese  and  Indian  lac- 
quers, little  is  known  except  as  to  their  production  as  crude  materials. 
The  Japanese  lacquer  has  been  more  fully  described,  and  the  methods 
of  applying  it  attentively  followed.  As  the  varnish  flows  from  the 
incisions  in  the  trees  of  the  Rhus  species  it  is  a  milky  juice,  which,  on 


120         INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

exposure,  quickly  darkens  and  blackens  in  color.  After  resting  in  tubs 
for  some  time  the  juice  becomes  thick  and  viscous,  the  thicker  portion 
settles  at  the  bottom  of  the  vessel,  and  from  it  the  thinner  top  stratum 
is  separated  by  decanting.  Both  qualities  are  strained  to  free  them 
from  impurities,  and  when  ready  for  use  they  have  a  rich  brown-black 
color,  which,  however,  in  thin  layers  presents  a  yellow,  transparent 
aspect.  This  varnish,  when  applied  to  any  object,  becomes  exceedingly 
hard  and  unalterable,  and  with  it  as  a  basis  all  the  colored  lacquers 
of  Japan  are  prepared.  The  black  variety  of  the  lacquer  is  prepared  by 
stirring  the  crude  varnish  for  a  day  or  two  in  the  open  air,  by  which 
it  becomes  a  deep  brownish-black.  Towards  the  completion  of  the 
process,  a  quantity  of  highly  ferruginous  water,  or  of  an  infusion  of 
gall-nuts  darkened  with  iron,  is  mixed  with  the  varnish,  and  the  stirring 
and  exposure  are  continued  till  the  added  water  has  entirely  evapo- 
rated, leaving  a  rich  jet-black  varnish  of  proper  consistency.  In  pre- 
paring the  fine  qualities  of  Japanese  lacquer,  the  material  receives 
numerous  coats,  and  between  each  coating  the  surface  is  carefully 
ground  and  smoothed.  The  final  coating  is  highly  polished  by  rubbing, 
and  the  manner  in  which  such  lacquered  work  is  finished  and  orna- 
mented presents  endless  variations.  The  durability  of  Japanese  lacquer- 
work  is  such  that  it  can  be  used  for  vessels  to  contain  hot  tea  and  other 
food,  and  it  is  even  unaffected  by  highly-heated  spirituous  liquors. 

Linseed-oil  Varnishes. — The  method  of  burning  linseed  or  similar 
drying  oil  in  order  to  develop  its  varnish-forming  character  has  been 
described  (see  p.  113).  The  use  of  metallic  oxides  and  salts  as  driers 
has  also  been  referred  to.  In  this  connection  an  additional  word  may 
be  had.  While  litharge  and  lead  acetate  are  commonly  used,  they  must 
be  replaced  by  manganese  or  other  driers  when  the  boiled  oil  is  to  be 
used  as  the  basis  of  zinc  oxide  paint.  Lately,  manganese  borate  has 
been  strongly  recommended  as  a  drier,  and  it  is  asserted  that  it  is 
capable  of  giving  rapid  drying  qualities  to  linseed  oil  when  it  is  heated 
a  sufficient  length  of  time  (from  ten  to  fourteen  days)  at  a  temperature 
of  only  40°  C.  Such  a  boiled  oil  would,  of  course,  be  lighter  in  color 
than  if  treated  at  a  higher  temperature.  Liquid  driers  are  also  in 
use  at  present  which  have  the  advantage  of  acting  gradually  upon  the 
linseed  oil  without  the  aid  of  heat,  so  that  a  boiled  oil  of  very  light  color 
is  obtainable.  These  driers  contain  manganese  and  lead  linoleates  and 
resinates,  and  concentrated  solutions  in  oil  or  turpentine  are  prepared 
for  addition  to  the  oil  to  be  oxidized.  Boiled  oil  is  often  bleached  by 
sunlight,  and  always  improves  by  keeping,  as  impurities  gradually 
settle  out,  and  its  drying  qualities  develop  by  age. 

The  most  important  of  the  linseed-oil  resin  varnishes  are:  Amber 
varnish,  the  most  durable  and  resisting  oil  varnish,  but  unfortunately 
of  dark  color;  copal  varnish,  the  finest  of  all  the  oil  varnishes,  nearly 
as  hard  and  durable  as  amber  varnish,  much  paler  in  color,  and  drying 
more  quickly ;  and  kauri  resin  and  colophony  resin  for  inferior  var- 
nishes. The  best  oil  varnishes  are  made  from  "fused  "  copal  or  amber, 
with  boiled  linseed  oil,  subsequently  thinned  out  with  oil  of  turpentine. 


PRODUCTS.  121 

Spirit  varnishes  are  easily  obtained  perfectly  clear;  they  dry  very 
rapidly,  and  leave  smooth,  lustrous  films,  which  appear  at  first  unex- 
ceptionable. But  slight  vibrations  and  changes  of  temperature  soon 
develop  innumerable  small  cracks,  in  consequence  of  which  it  loses  its 
lustre,  and  if  the  varnish  layer  was  thick  it  begins  to  peel  off.  The 
reason  of  this  is  that  the  film  consisted  simply  of  unaltered  resin,  spread 
in  a  thin  layer,  and  as  most  of  the  resins  are  brittle  by  nature,  slight 
shocks  or  changes  of  temperature,  inducing  contraction  or  expansion 
of  the  article  varnished,  will  cause  the  resin  film  to  break.  What  is 
true  of  alcoholic  varnishes  applies,  of  course,  also  to  all  varnishes  where 
the  solvent  of  the  resin  takes  no  part  in  the  formation  of  the  film.  The 
more  volatile  the  solvent  the  quicker  the  film  is  deposited  and  the  easier 
it  cracks.  Two  methods  of  obviating  this  difficulty  are  in  use:  first,  to 
mix  with  the  brittle  resin  a  soft,  balsam-like  resin,  and,  second,  to  mix 
spirit  varnish  with  one  prepared  with  turpentine  oil. 

Turpentine  varnishes  are  seldom  used  exclusively  as  such  because  of 
the  strong  and  persistent  turpentine  odor.  When  used  alone  they  give 
films  as  perfect  as  those  gotten  by  the  use  of  spirit  varnishes,  but  tougher 
and  drying  more  slowly  than  these  latter.  Usually,  however,  turpen- 
tine oil  is  used  in  connection  with  boiled  linseed  or  other  drying  oil  in 
varnish  manufacture,  as  in  the  case  given  of  copal  varnish,  before  de- 
scribed. (See  p.  114.)  The  resins  used  for  turpentine-oil  varnishes  are 
the  varieties  of  copal,  amber,  sandarac,  dammar,  mastic,  and  coniferous 
resins. 

Japans  are  simply  varnishes  that  yield,  on  drying,  very  hard,  bril- 
liant coatings  upon  paper,  wood,  or  metal,  analogous  to  the  natural 
lacquer  of  Japan,  before  described.  The  effecting  of  this  result  is  gotten 
in  general  by  exposing  the  articles  to  high  temperatures  in  stoves  or 
hot  chambers  subsequent  to  the  application  of  the  varnish.  This  sup- 
plementary heating  process  is  called  "japanning."  It  is  done  with  clear, 
transparent  varnishes,  in  black  and  in  colors,  but  black  japan  is  the 
most  characteristic  and  common  style  of  work.  Black  japan  varnish 
contains  asphaltum  as  the  basis,  and  when  applied  in  several  layers, 
each  of  which  is  separately  dried  in  the  stove  at  a  heat  rising  to  300°  P. 
(149°  C.),  is  susceptible  of  a  high  polish.  Japanning  may  be  regarded 
as  a  process  intermediate  between  ordinary  painting  and  enamelling. 
It  is  very  extensively  applied  in  the  finishing  of  ordinary  hardware 
goods  and  domestic  iron-work,  deed-boxes,  clock-dials,  and  papier- 
mache  articles.  The  process  is  also  applied  to  blocks  of  slate  for  making 
imitation  of  black  and  other  marbles  for  chimney-pieces,  etc.,  and  a 
modified  form  of  japanning  is  employed  for  prepared  enamel,  japan, 
or  patent  leather. 

3.  PRINTING  INKS. — The  character  of  printing  inks  has  been  suffi- 
ciently indicated  in  the  description  of  their  manufacture.  (See  p.  115.) 

.4.  MISCELLANEOUS  PRODUCTS  FROM  RESINS  AND  ESSENTIAL  OILS. — 
(1)  Sealing-wax  is  a  valuable  product  of  manufacture  from  shellac. 
Venice  turpentine  is  always  added  to  the  shellac  to  make  it  more  fusible 
and  less  brittle,  and  some  mineral  coloring  matter,  which,  in  the  case  of 


122          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

the  common  red  variety,  is  always  vermilion.  For  black  sealing-wax 
the  best  ivory-black  is  used,  for  golden-colored  wax,  "mosaic  gold  " 
(stannic  sulphide),  for  green  wax,  powdered  verdigris.  For  the  com- 
moner varieties,  earthy  materials,  like  chalk,  magnesia,  burnt  plaster, 
barytes,  or  infusorial  earth,  are  added  for  the  double  purpose  of  making 
it  less  fusible  and  to  weight  it.  Perfumed  sealing-waxes  are  scented  with 
benzoin,  Peru  and  Tolu  balsams,  and  storax.  As  a  substitute  for,  or 
adulterant  of,  shellac  in  the  manufacture  of  sealing-wax,  gum  acaroides 
has  recently  come  into  use. 

(2)  Rosin  Oil. — In  recent  years  great  importance  has  attached  to  the 
products  of  the  dry  distillation  of  common  colophony  resin  or  "rosin." 
It  yields,  on  distillation,  two  valuable  products:  first,   from  three  to 
seven  per  cent,  of  a  light  fraction  known  as  rosin  spirit,  or  "pinoline," 
and,  second,  from  seventy  to  eighty-five  per  cent,  of  rosin  oil,  a  violet- 
blue  fluorescing  liquid,  varying  in  specific  gravity  from  .98  to  1.1.     The 
pinoline  is  used  as  an  illuminant  and  as  a  substitute  for  turpentine  oil 
in  varnish  manufacture.     The  rosin  oil  has  a  large  use  as  a  lubricant, 
especially  for  machinery  and  wagon-wheels.     It  is  used  in  the  condition 
of  "rosin  grease  "  (made  by  stirring  rosin  oil  with  the  milk  of  lime), 
and  largely  as  a  substitute  for  linseed  oil  in  the  manufacture  of  printers' 
ink.     (See  p.  115.)     Moreover,  as  it  can  be  deprived  of  its  fluorescence 
or  "bloom  "  in  various  ways    (exposure  to  sunlight,  treatment  with 
hydrogen  peroxide,  nitro-benzene,  dinitro-naphthalene,  etc.),  it  can  be 
used  in  adulterating  olive,  rape,  and  sperm  oils.    The  best  mineral  lubri- 
cating oils  are  also  adulterated  with  it  at  times. 

(3)  Oil-cloth   and  Linoleum. — The   general   outlines  of  the   manu- 
facture of  these  products,  as  given  on  page  116,  allow  one  to  form  an 
idea  of  the  character  of  them. 

Oil-cloth  is  a  firm  but  flexible  fabric,  which  by  its  treatment  has 
been  made  water-proof  and  impervious  to  atmospheric  influences.  It 
can  be  washed  and  cleansed,  and,  under  ordinary  wear,  retains  for  a 
considerable  time  its  lustre  and  brilliancy  of  printed  pattern.  It  is, 
however,  cold  and  hard,  and,  unless  well  seasoned,  the  pattern  is  liable 
to  wear  off.  The  covering  film  will  not  stand  much  bending  without 
cracking,  and  then  it  rapidly  disintegrates. 

Linoleum  is  softer  and  more  elastic  to  the  feet,  and,  if  the  composi- 
tion has  been  properly  made,  shows  great  elasticity  and  toughness,  so 
that  its  wearing  powers  are  notably  greater  than  those  of  oil-cloth.  In 
laying  down  linoleum,  the  edges  may  be  cemented  to  the  floor  by  using 
a  thick  solution  of  shellac  in  methylated  spirit. 

(4)  Linseed-oil  Caoutchouc. — For  the  preparation  of  this  substitute 
for  caoutchouc,  linseed  oil  is  heated  to  a  high  temperature  for  a  con- 
siderable time  until  it  becomes  dark  and  has  changed  into  a  tough  mass. 
It  is  stated  that  when  vulcanized  by  the  aid  of  sulphur  chloride  it  can 
be  used  as  a  substitute  or  adulterant  of  genuine  caoutchouc. 

5.  INDIA-RUBBER  AND  GUTTA-PERCHA  PRODUCTS. — In  noting  the  prop- 
erties of  crude  caoutchouc  it  was  stated  that  the  raw  caoutchouc,  while 
elastic  at  ordinary  temperatures,  did  not  show  the  same  character  when 


PRODUCTS.  123 

chilled,  as  it  became  hard,  and  when  heated  it  lost  the  elastic  feature 
entirely.  On  the  other  hand,  vulcanized  caoutchouc  or  manufactured 
rubber  shows  no  change  in  its  elasticity,  even  within  very  wide  limits 
of  temperature.  Freshly-cut  surfaces,  on  being  pressed  together,  will 
not  adhere,  as  is  the  case  with  raw  caoutchouc ;  it  swells  up  only  slightly 
in  bisulphide  of  carbon,  oil  of  turpentine,  and  other  solvents,  while  the 
raw  caoutchouc  swells  up  greatly  and  even  dissolves  in  part.  The  vul- 
canized rubber  is  much  more  impervious  to  water  than  the  raw  mate- 
rial. As  stated- before,  not  all  of  the  sulphur  present  in  the  vulcanized 
rubber  is  chemically  combined.  A  large  excess  of  uncombined  sulphur 
is,  however,  deleterious  to  the  goods,  as  it  causes  them  to  lose  their  elas- 
ticity when  they  are  stored  for  a  few  years.  If  such  goods  are  treated 
with  alkaline  solutions,  the  free  sulphur  can  be  removed  without  impair- 
ing the  elastic  character  of  the  vulcanized  caoutchouc.  Hard  rubber, 
prepared,  as  described  before,  from  crude  caoutchouc,  with  a  larger 
percentage  of  sulphur,  has  a  black  color  and  takes  a  high  degree  of 
polish.  Articles  of  this  material  can  also  be  gotten  of  any  desired  color, 
as  in  the  case  of  the  dental  rubber  previously  referred  to.  Eesins,  like 
shellac,  are  often  added  to  give  elasticity  to  the  hard  rubber,  the  amount 
of  resin  capable  of  being  taken  up  being  considerable,  equalling  at  times 
fifty  per  cent,  of  the  combined  weight  of  the  caoutchouc  and  sulphur. 
Hard  rubber  becomes  strongly  electrified  by  rubbing,  and  hence  is  used 
in  various  plate  electrical  machines,  while  its  non-conducting  qualities 
make  it  valuable  for  insulators  in  various  forms  of  telegraphic  appa- 
ratus. Hard  rubber  is  unacted  upon  by  strong  mineral  acids  and  other 
chemicals,  and  hence  is  used  for  acid-pumps  and  connections,  for  spat- 
ulas, photographic  dishes,  etc. 

Rubber  substitute,  or  so-called  "artificial  rubber,"  is  made  by  acting 
upon  linseed,  rape,  poppy,  hemp,  and  cotton-seed  oils  with  sulphur 
chloride,  and  removing  the  hydrogen  chloride  formed  by  after-treat- 
ment with  milk  of  lime.  The  result  is  a  tough  rubber-like  mass,  which, 
however,  becomes  more  or  less  brittle  on  keeping. 

It  is  asserted  that  a  better  product  is  obtained  by  using  oxidized  or 
"blown  "  oils  for  the  treatment  with  the  sulphur  chloride.  The  acid 
' '  sludge  ' '  from  the  refining  of  petroleum  is  also  converted  into  a  rubber 
substitute  by  heating  and  removal  of  the  free  acid. 

Gutta-percha,  in  the  pure  as  well  as  the  vulcanized  condition,  has 
been  adapted  to  a  multitude  of  uses.  One  of  the  most  important  uses  of 
gutta-percha  is  as  a  material  for  the  matrices  or  moulds  for  coins, 
medals,  smaller  art  castings,  etc.,  and  all  forms  of  galvano-plastic  work. 
,  The  pure  gutta-percha  serves  very  well  to  take  imprints,  but  for  over- 
laying matrices  or  moulds  compositions  of  gutta-percha  and  caoutchouc 
must  be  used,  to  unite  plasticity  when  heated  with  sufficient  elasticity 
to  allow  of  the  matrix  being  removed  without  injury  to  the  impression. 
The  chief  use  for  gutta-percha,  however,  is  for  telegraphic  cable  insu- 
lation (every  nautical  mile  of  cable  requiring  about  one-half  of  a  ton 
of  gutta-percha),  and  the  chief  purchaser  and  worker  in  gutta-percha, 
therefore,  is  the  "Telegraph  Construction  and  Maintenance  Company," 


124          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

of  London,  who  buy  up  the  crude  gutta-percha  through  their  agents  in 
Singapore.  The  gutta-percha  is  covered  upon  the  wires  by  pressing. 
The  partly  vulcanized  and  warm  gutta-percha  mass  is  forced  out  of  a 
powerful  press  along  with  and  around  the  wire  or  wires  to  be  covered. 
The  gutta-percha  must  have  previously  been  well  kneaded  to  remove  the 
air  thoroughly  from  it,  so  that  it  may  pack  uniformly. 

Gutta-percha  is  also  incorporated  with  powdered  wood  and  saw- 
dust, making  a  composition  which  is  very  hard  and  can  be  worked  by 
means  of  the  saw  and  turning-lathe  into  a  variety  of  shapes. 

IV.  Analytical  Tests  and  Methods. 

1.  FOR  ESSENTIAL  OILS. — Essential  oils  are  extremely  liable  to  adul- 
teration, the  high  price  of  many  of -the  finer  ones  lending  to  this  ten- 
dency. The  usual  adulterations  are  with  alcohol,  chloroform,  oil  of 
turpentine,  fixed  oils,  both  vegetable  and  mineral,  and  spermaceti,  and 
by  mixing  the  cheaper  essential  oils  with  the  more  expensive.  The  exact 
determination  of  physical  constants,  such  as  specific  gravity  and  optical 
rotation,  becomes,  therefore,  very  important  as  well  as  the  recognition 
of  characteristic  chemical  constituents. 

The  detection  of  fatty  oils,  resins,  or  spermaceti  can  often  be  effected 
by  simply  placing  a  drop  of  a  suspected  oil  upon  a  piece  of  white  paper 
and  exposing  it  for  a  short  time  to  heat.  If  the  oil  is  pure  it  will 
entirely  evaporate;  but  if  one  of  these  adulterants  be  present,  a  greasy 
or  translucent  stain  will  be  left  on  the  paper.  These  substances  will 
also  remain  undissolved  when  the  oil  is  agitated  with  thrice  its  volume 
of  rectified  spirit. 

Alcohol  in  essential  oils  may  be  detected  by  agitating  the  oil  with 
small  pieces  of  dry  calcium  chloride.  These  remain  unaltered  in  a  pure 
essential  oil,  but  dissolve  in  one  containing  alcohol,  and  the  resulting 
solution  separates,  forming  a  distinct  stratum  at  the  bottom  of  the  vessel. 
When  only  a  very  little  alcohol  is  present,  the  pieces  merely  change 
their  form  and  exhibit  the  action  of  the  solvent  on  their  angles  or  edges, 
which  become  more  or  less  obtuse  or  rounded.  If  the  experiment  be 
performed  in  a  graduated  tube  and  a  known  measure  of  the  oil  em- 
ployed, the  diminution  in  its  volume  will  give  that  of  the  alcohol  mixed 
with  it.  Dragendorff  recommends  the  use  of  metallic  sodium,  which 
does  not  act  on  hydrocarbons,  and  but  slightly  in  the  cold  on  oxygenated 
essential  oils  if  pure  and  dry,  but  in  the  presence  of  ten  or  even  five  per 
cent,  of  alcohol  a  small  piece  of  the  sodium  is  dissolved,  while  a  brisk 
evolution  of  gas  takes  place.  Aniline-red  (magenta)  is  insoluble  in 
essential  oils  if  pure  and  dry,  but  in  the  presence  of  a  small  proportion 
of  alcohol  they  acquire  a  pink  or  red  color.  This  adulteration  with 
alcohol  is  said  to  be  very  common,  as  it  is  a  frequent  practice  of  drug- 
gists to  add  a  little  of  the  strongest  rectified  spirit  to  their  essential 
oils  to  render  them  transparent,  especially  in  cold  weather.  Oil  of  cassia 
is  a  notable  example  of  an  oil  treated  in  this  way. 

The  adulteration  of  essential  oils  with  fixed  oils  is  best  distinguished 


ANALYTICAL  TESTS  AND  METHODS. 


125 


by  what  is  termed  "steam  distillation."  The  essential  oils  all  distil 
over  with  steam  at  100°  C.,  while  resinous  matters  and  fixed  oils,  added 
as  adulterants,  will  remain  in  the  retort.  The  adulteration  of  the  finer 
essential  oils  with  cheaper  essential  oils  is  constantly  met  with.  Thus, 
the  expensive  oil  of  cassia  is  adulterated  with  oil  of  cedarwood;  oil  of 
rose  with  oil  of  geranium;  and  oil  of  geranium  with  oil  of  turpentine. 
Noting  the  specific  gravity  carefully  where  that  is  characteristic,  and 
noting  the  odor  on  evaporating,  are  methods  most  generally  resorted  to 
for  the  detection  of  these  fraudulent  admixtures. 

In  the  case  of  such  oils  as  contain  esters,  such  as  oils  of  peppermint 
and  rosemary,  the  percentage  of  menthyl  acetate,  bornyl  acetate,  etc., 
can  be  ascertained  by  a  saponification  with  half-normal  potassium  hy- 
droxide solution.  The  free  alcohol  also  present  in  these  oils  is  then 
determined  by  an  acetylization  with  acetic  anhydride  and  anhydrous 
sodium  acetate,  followed  by  a  saponification  test  made  upon  the  washed 
and  dried  acetylized  oil.  Exact  directions  for  carrying  out  these  deter- 
minations with  official  essential  oils  are  given  in  the  U.  S.  Pharma- 
copoeia. 

The  phenolic  constituents  of  certain  essential  oils  like  the  eugenol 
of  oils  of  cloves  and  pimenta  and  the  thymol  of  oil  of  thyme  can  also 
be  determined  by  the  use  of  aqueous  solutions  of  sodium  or  potassium 
hydroxide  and  reading  off  the  loss  in  the  oily  layer  which  ensues  on 
shaking. 

The  purity  of  oil  of  turpentine,  as  commercially  the  most  important 
of  the  essential  oils,  is  often  a  question  to  be  determined.  The  most 
usual  adulterants  of  oil  of  turpentine  are  light  petroleum-naphtha, 
known  as  "turpentine  substitute,"  "rosin  spirit,"  and  of  late  a  so- 
called  "light  camphor  oil,"  gotten  as  a  side-product  in  the  manufacture 
of  safrol.  The  following  tabular  statement  of  Allen*  shows  the  char- 
acters of  oil  of  turpentine,  rosin  spirit,  and  petroleum-naphtha  under 
the  influence  of  different  reagents: 


Turpentine  oil. 

Rosin  spirit. 

Petroleum-naphtha. 

1.  Optical  activity  .  .  . 

Active. 

Usually  none. 

None. 

2.  Specific  gravity  .   .    • 

.860  to  .872. 

.856  to  .880. 

.700  to  .740. 

3.  Temperature  of  dis- 

156° to  180°. 

Gradual  rise. 

Gradual  rise. 

tillation,  C.  °. 

4.  Action    in  the   cold 
on  coal-tar  pitch. 

Readily  dissolves  pitch 
to  a  deep-brown  solu- 

Readily dissolves  pitch 
to  a  deep-brown  solu- 

Very slight  action,  lit- 
tle or  no  color. 

tion. 

tion. 

5.  Behavior  with  abso- 

Homogeneous     m  i  x- 

Homogeneous      m  i  x- 

No  apparent  solution. 

lute    phenol,   3    of 

ture. 

ture. 

sample  to  1  of  phe- 

nol, at  20°  C. 

6.  Behavior   on    shak- 

Homogeneous     m  i  x- 

Homogeneous     m  i  x- 

Liquid  separates  into 

ing  3   parts  of  cold 

ture. 

ture. 

two  layers  of  nearly 

sample  with  1  part 

equal  volume. 

castor  oil. 

7.  Bromine  absorption. 

203  to  236. 

184  to  203. 

10  to  20. 

8.  Behavior    witn   sul- 
phuric acid. 

Almost  completely 
polymerized. 

Polymerized. 

Very  little  action. 

It  will  be  seen  that  the  presence  of  petroleum  spirit  can  be  indicated 
by  almost  all  of  these  reagents,  while  that  of  rosin  spirit  would  hardly 

*  Allen,  Commercial  Org.  Anal.,  2d  ed.,  ii,  p.  439. 


126          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

be  shown.  H.  E.  Armstrong*  recommends  a  process  which  consists  of 
agitating  the  suspected  turpentine  sample  first  with  sulphuric  acid  and 
water  (2:1),  carefully  avoiding  too  high  a  rise  of  temperature.  This 
gradually  polymerizes  the  genuine  oil  of  turpentine,  changing  it  to  a 
viscid  non- volatile  oil.  The  sample  is  then  distilled  with  steam,  and  that 
which  is  volatile  at  this  temperature  is  now  treated  with  4 :  1  sulphuric 
acid  and  water.  The  polymerization  of  the  turpentine  is  usually  com- 
pleted by  this  treatment,  while  any  petroleum-naphtha  present  is  not 
affected,  and  remains  as  volatile  as  before.  A  final  steam  distillation 
will  give  the  petroleum-naphtha  originally  present  in  the  turpentine 
sample.  Rosin  spirit  is  partly  polymerized  in  this  treatment,  while 
volatile  hydrocarbons  remain,  but  its  presence  is  much  harder  to  indi- 
cate certainly  than  that  of  petroleum. 

Dunwoody  has  shown  that  mixtures  of  turpentine  and  petroleum  are 
much  less  soluble  in  ninety-nine  per  cent,  acetic  acid  than  pure  turpen- 
tine. While  ten  cubic  centimetres  of  pure  turpentine  are  soluble  in  an 
equal  volume  of  a  mixture  of  ninety-nine  parts  glacial  acetic  acid  and 
one  part  water,  it  requires  forty  cubic  centimetres  of  such  mixture  when 
the  turpentine  contains  ten  per  cent,  of  petroleum,  sixty  cubic  centi- 
metres if  twenty  per  cent,  of  petroleum  be  present,  and  so  on  in  increas- 
ing rates. 

The  Prussian  custom  regulations  prescribe  a  similar  test  with  aniline 
oil.  Ten  cubic  centimetres  of  the  sample  are  shaken  up  in  a  stoppered 
jar  with  ten  cubic  centimetres  of  aniline  oil.  If  pure  turpentine  is 
used,  a  clear  solution  follows;  if  petroleum  is  present,  two  layers  are 
formed. 

The  oxidizing  effect  of  fuming  nitric  acid  is  also  availed  of  to  detect 
the  presence  of  mineral  oil  in  turpentine,  as  the  latter  is  entirely  oxi- 
dized, while  the  former  is  not  affected.  With  a  pure  or  nearly  pure 
turpentine  the  action,  however,  is  so  violent  as  to  be  dangerous.  The 
presence  of  rosin  spirit  in  turpentine  oil  is  said  to  be  detected  by  shak- 
ing the  suspected  sample  with  an  aqueous  solution  of  sulphurous  acid. 
This  imparts  a  bright  yellow  color  to  rosin  spirit  but  does  not  color  pure 
turpentine,  benzene  or  gasolene. 

The  iodine  absorption  percentages  with  Hubl's  reagent  (see  p.  89) 
for  a  large  number  of  essential  oils  have  been  determined  by  R.  H. 
Davies,f  who  finds  that  the  differences  in  absorption  power  are  very 
much  greater  in  the  case  of  essential  than  in  that  of  fixed  oils.  Some 
volatile  oils  do  not  absorb  any  appreciable  amount  of  iodine,  while 
others  will  remove  from  solution  four  times  their  weight,  or  four  hun- 
dred per  cent.  Thus,  oil  of  turpentine  shows  an  absorption  equivalent 
of  three  hundred  and  seventy-seven  per  cent.,  and  wood  turpentine  two 
hundred  and  twelve  per  cent. 

2.  FOR  RESINS. — The  tests  for  resins  or  resin  acids,  when  admixed 

*  Journ.  Soe.  Chem.  Ind.,  i,  p.  480. 

t  Phar.  Journ.  and  Trans.,  April,  1889,  p.  821,  and  Amer.  Journ.  of  Pliar.,  1889, 
p.  301. 


ANALYTICAL  TESTS  AND  METHODS. 


127 


with  fats  or  fatty  oils,  have  been  referred  to  under  the  discussion  of  the 
latter.  (See  p.  91.) 

From  admixture  with  the  neutral  fixed  oils  resins  may  be  separated 
by  treating  the  mixture  with  alcohol  of  about  .85  specific  gravity.  The 
alcohol  is  subsequently  separated,  and  the  dissolved  resin  recovered  by 
evaporating  it  to  dryness.  Acid  resins,  such  as  common  colophony,  may 
be  separated  from  the  neutral  fats  by  boiling  the  substance  with  a 
strong  solution  of  sodium  bicarbonate  or  borax.  After  cooling,  the 
aqueous  liquid  is  separated  from  the  oil  and  the  resin  precipitated  from 
its  solution  in  the  sodium  salt  by  adding  hydrochloric  acid. 

Resins  may  be  separated  from  the  essential  oils  and  camphors  in 
admixture  with  which  they  so  frequently  occur  by  distilling  in  a  current 
of  steam. 

The  resins  show  some  considerable  differences  when  examined  by 
the  two  methods  of  bromine  absorption  and  saponification  equivalent, 
before  referred  to  under  the  fatty  oils.  (See  p.  88.)  Mills  and  Muter* 
have  determined  the  bromine  absorptions,  and  E.  J.  Millsf  the  propor- 
tions of  potash  neutralized  by  various  resins.  The  following  table  gives 
a  summary  of  their  results : 


KIND  OF  RESIN. 

KOH  neutralized 
per  cent. 

Saponification 
equivalent. 

Bromine  absorp- 
tion. 

Hydrobromic 
acid  formed. 

Kosin  (refined)  .... 
Shellac  

18.1 
23.0 

308.6 
242.7 

112.7 
5.2 

Shellac  (bleached)    .    . 
Benzoin   

18.2 
22.3 

306.9 
256.0 

4.6 
38.9 

Some. 

Amber  

16.1 

347.6 

53.5 

Some. 

Anime  

9.5 

585.5 

60.2 

Much. 

Gamboge     ...... 

15.5 

361.1 

71.6 

Much. 

Copal    

12.4 

450.8 

89.9 

Much. 

Copal  (reduced  to  f  by 
boiling)    

12.9 

433.4 

84.5 

Much. 

Sandarach   

16.4 

340.6 

96.4 

Very  much. 

Kauri   

12.9 

433.4 

108.2 

Thus     

21.0 

340.6 

108.5 

Dammar  

5.2 

1068.1 

117.9 

Much. 

Elemi  

3  3 

1697.9 

122.2 

Very  much. 

11.7 

478.6 

124.3 

Much. 

For  the  detection  of  rosin  as  an  adulterant  of  shellac 'the  Storch 
reaction  with  acetic  anhydride  may  be  used.  A  more  delicate  reaction, 
recommended  by  Parry,  is  to  dissolve  the  sample  in  alcohol,  pour  the 
solution  into  water  and  collect  on  a  filter  the  impalpable  powder,  which  is 
then  dried  and  rubbed  up  with  petroleum  ether.  This  solution  after 
filtration  is  shaken  up  with  water  containing  a  trace  of  copper  acetate. 
In  the  presence  of  rosin  the  petroleum  ether  is  colored  emerald  green. 
Pure  shellac  gives  no  color. 

The  constantly-widening  use  of  rosin  oil  makes  the  tests  for  its 
presence  of  considerable  importance.  Rosin  oil  gives  a  characteristic 
violet  color  with  anhydrous  stannic  chloride  or  bromide.  If  it  is  mixed 


Journ.  Soc.  Chem.  Ind.,  iv,  p.  97. 


flbid.,  v,  p.  221. 


128          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

with  fatty  oils,  A.  H.  Allen  points  out  that  the  test  may  still  be  suc- 
cessfully applied  by  distilling  the  mixture  and  applying  the  test  to  the 
first  fraction  which  passes  over. 

Demski  and  Morawski*  recommend  the  use  of  acetone  for  the  detec- 
tion and  rough  determination  of  rosin  oil  in  mineral  oils.  According  to 
these  chemists,  rosin  oils  are  miscible  with  acetone  in  all  proportions, 
while  mineral  oils  require  several  times  their  volume  of  acetone  to  effect 
solution.  The  test  is  applied  by  agitating  fifty  cubic  centimetres  of  the 
sample  with  twenty-five  cubic  centimetres  of  acetone.  If,  on  allowing 
the  mixture  to  stand,  it  separates  into  two  layers,  ten  cubic  centimetres 
of  the  upper  or  acetonic  layer  should  be  removed  with  a  pipette  and 
evaporated,  and  the  residual  oil  weighed.  In  the  case  of  pure  American 
or  Galician  lubricating  oil  the  residue  will  weigh  about  two  grammes, 
but  only  half  this  quantity  will  be  obtained  from  Wallachian  or  Cau- 
casian oil.  It  is  stated  that  mixtures  of  rosin  oil  with  the  lubricating 
oils  from  American  and  Galician  petroleum  are  permanently  soluble  in 
half  their  volume  of  acetone,  if  the  proportion  of  rosin  oil  exceeds 
thirty-five  per  cent,  of  the  mixed  oil,  but  that  complete  solution  is  not 
effected  in  the  case  of  Wallachian  and  Caucasian  oils  unless  the  rosin 
oil  constitutes  at  least  fifty  per  cent,  of  the  mixture.  Ragosine  cylinder 
oil  requires  an  addition  of  rosin  oil  equal  to  fifty-three  per  cent,  of  the 
mixture  to  become  soluble  in  half  its  volume  of  acetone. 

3.  FOB  VARNISHES. — The  most  important  constituent  which  enters 
into  the  manufacture  of  varnishes  is  undoubtedly  the  linseed  or  other 
drying  oil.    Linseed  oil  (see  p.  54)  is  liable  to  be  adulterated  with  other 
vegetable  oils,  with  fish  oils,  with  mineral  and  rosin  oils,  and  with  rosin 
itself.     As  mineral  and  foreign  seed  oils  are  lighter  in  specific  gravity 
than  linseed  oil,  while  rosin  and  rosin  oil  are  much  heavier,  by  the 
judicious  use  of  a  suitable  mixture  of  mineral  and  rosin  oils  extensive 
adulteration  can  be  effected  without  alteration  of  the  density.     The 
analysis  of  a  linseed  oil  supposed  to  be  adulterated  would  be  made 
according  to  the  scheme  given  before  (see  p.  92)  for  the  analysis  of  a 
fatty  oil  containing  foreign  admixtures.    A.  H.  Allen  gives  also  a  rather 
elaborate  method,  which  he  states  is  better  adapted  for  a  boiled  linseed 
oil,  for  the  details  of  which  the  reader  is  referred  to  Allen's  "Com- 
mercial Organic  Analysis,"  3d  ed.,  vol.  ii,  Part  ii,  p.  155. 

4.  FOR    CAOUTCHOUC    AND    GUTTA-PERCHA. — The    adulterations    of 
caoutchouc  are  both  mineral,  or  inorganic,  and  organic  in  character.    A 
careful  incineration  of  a  given  specimen  in  a  porcelain  crucible  will 
leave  any  mineral  admixture,  as  ash.    Oxide  of  zinc,  gypsum,  and  such 
admixtures    are    thus    recognized.      As   many    samples    of    vulcanized 
rubber  now  contain  cheapening  agents  of  an  organic  nature,  such  as 
oils  and  rubber  substitutes  added  for  the  purpose  of  cheapening  the 
product,  some  more  complete  method  of  analysis  is  needed  to  enable 
one  to  distinguish  them.     Weber  has  proposed  a  method  of  fractional 
solution  by  the  aid  of  different  solvents  that  has  been  largely  used.    The 
sample  is  first  extracted  with  acetone,  which  dissolves  out  fatty  oils, 

*  Ding.  Polytech.  Journ.,  cclviii,  p.  82. 


BIBLIOGRAPHY  AND  STATISTICS.  129 

mineral  oils,  resin  oils,  resins,  and  free  sulphur.  The  residue  from  this 
extraction  may  then  be  extracted  with  pyridine  to  take  out  pitch  and 
bituminous  bodies.  This  is  followed  by  a  treatment  with  alcoholic 
potash  which  will  saponify  and  extract  oxidized  or  blown  oils  and  the 
chlorosulphide  compounds  of  the  same.  The  residue  from  this  treat- 
ment will  contain  the  true  rubber  and  the  sulphur  of  vulcanization, 
together  with  inorganic  filling  materials.  The  rubber  of  this  residue 
is  then  to  be  determined  either  by  extraction  with  a-nitronaphthalene, 
or  by  converting  it  into  a  nitrosite  by  the  action  of  nitrogen  peroxide 
gas  on  the  residue  suspended  in  dry  chloroform  or  benzene. 

The  total  sulphur  having  been  determined  on  a  separate  sample  by 
the  aid  of  strong  nitric  acid  or  sodium  peroxide,  and  the  free  sulphur 
having  been  obtained  from  the  acetone  extract,  the  sulphur  of  vul- 
canization is  obtained  by  difference  after  allowing  for  any  sulphur 
found  in  the  mineral  residue. 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

1874. — Gums,  Eesins,  Oleo-resins,  etc.,  of  India,  M.  C.  Cooke,  London. 

1875. — Rohmaterialen  fiir  Lack  and  Firniss  Fabrikation,  L.  E.  Andes,  Wien. 

1877. — Die  Fabrikation  der  Aetherische  Oele,  A-skinson,  Wien. 

Perfumery  and  Kindred  Arts,  Christian!,  Philadelphia. 
1879. — Pharmacographia,   Fliickiger  and  Hanbury,  2d  ed.,  London. 

Die  Kautchuk  Industrie,  F.  Clouth,  Weimar. 
1880.— Die  Fabrikation  des  Wachstuches,  R.  Esslinger,  Leipzig. 
1883. — Die  Rohstoffe  des  Pflanzenreiches,  J.  Wiesner,  Leipzig. 

Caoutchouc  and  Gutta-percha,  Hoffer,  Philadelphia  and  London. 

Die    Fabrikation    der    Kaoutchuk    und    Gutta-percha    Waaren,    Heinzerling, 
Braunschweig. 

Painting  and  Painter's  Materials,  Condit  and  Scheller,  New  York. 
1884. — Handbuch  fiir  Anstreicher  und  Lackirer,  L.  E.  Andes,  Leipzig. 

Die  Pflanzenstoffe,  thiseman  und  Hilger,  2d  Auf.,  Berlin. 
1885. — Die  Fabrikation  der  Siegel-  und  Flaschenlacke,  L.  E.  And&s,  Leipzig. 

Chemische  Reactionen  zum  Nachweise  des  Terpentinols,  H.  Hager,  Berlin. 
1887. — India-Rubber  and  Gutta-percha  and  their  Cultivation,  R.  Ferguson,  Colombo. 
1888. — Pharmaceutische  Chemie,   Fliickiger,  2te  Auf.,   Berlin. 
1890. — Fabrikation  der  Lacke  und  Firnisse,  P.  Lohmann,  Berlin. 

Practical  Treatise  on  the  Raw  Material  and  Manufacture  of  Rubber,  G.  N. 
Nesienson,   New  York. 

Treatise  on  the  Manufacture  of  Perfumes,  etc.,  J.  H.  Snively,  New  York. 
1891. — Rubber  Hand-Stamps  and  Manipulation  of  Rubber,  J.  O'C.  Sloane,  New  York. 

Die  Fliichtige  Oele  Pflanzenreich's,  G.  Bornemann,  Weimar. 

Fossil  Resins,  Lawn  and  Booth,  New  York. 

Handbuch  der  Parfiimerie  und  Toilettenseifen,  C.  Deite,  Berlin. 

The  Art  of  Perfumery,  C.  H.  Piesse,  5th  ed.,  London. 
1892. — Practical  Treatise  on  Manufacture  of  Perfumery,  W.  T.  Brannt,  Philadelphia. 

Odorographia :  A  Natural  History  of  Perfume  Drugs,  J.  Ch.  Sawer,  2  vols., 
London. 

Lc  Caoutchouc  et  la  Gutta-percha,  E.  Chapel,  Paris. 

Perfumes  and)  their   Preparation,   G.   W.   Askinson,   J.   Furst,  trans.    Spon, 
London  and  New  York. 

The  Chemistry  of  Paints  and  Painting,  A.  H.  Church,  2d  ed.,  London. 

The  Manufacture  of  Volatile  and  Fat  Varnishes,  Lacquers,  Siccatives,  and 
Sealing  Waxes,  E.  Andes,  translated  by  W.  T.  Brannt,  Philadelphia. 

9 


130          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

1893. — Fabrication  des  Essences  et  des  Parfums,  P.  Durvelle,  Paris. 

Le  Caoutchouc  et  la  Gutta-percha,  R.  Bobet,  Paris. 

Pigments,  Paints,  and  Painting,  G.  Terry,  London. 

Varnishes,  Lacquers,  Printing  Inks,  etc.,  W.  T.  Brannt,  Philadelphia. 

The  Practical  Polish  and  Varnishmaker,  H.  C.  Standage,  London. 

Fabrication  des  Vernis,  L.  Naudin,  Paris. 
1894. — Descriptive  Catalogue  of  Essential  Oils,  etc.,  F.  B.  Power,  New  York. 

Das  Harz  der  Nadelhb'lzer,  H.  Mayr,  Berlin. 

Die  Riechstoffe  und  ihre  Verwendung,  St.  Nicrozwiski,  7th  Auf.,  Weimar. 

Odorographia,  Second  Series,  J.  Ch.  Sawer,  London. 
1895. — Couleurs  et  Vernis,  G.  Halphen,  Paris. 

Leinoel  und  Leinoel  Firniss,  H.  Amsel,  Zurich. 
1896. — Oils  and  Varnishes,  Jas.  Cameron,  3d  ed.,  London. 

Die  Harze  und  ihre  Producte,  G.  Thenius,  Wien. 

1897. — Linseed  Oil  Manufacture  and  Varnishes,  John  Bannon,  New  York  and  Chi- 
cago. 

1898. — Essai  des  Huiles  Essentielles,  H.  Labbi,  Paris. 
1899. — Die  Aetherischen  Oele,  Gildemeister  und  Hoffmann,  Berlin. 

Die  Gutta-percha,  Dr.  Eugen  Obach,  Dresden,  Blasewitz. 

Les  Huiles  Essentielles,  etc.,  Charabot,  Dupont  et  Pillet,  Paris. 

Manufacture  of  Varnishes,  A.  Livache,  translated  by  J.  G.  Mclntosh,  London. 

Mati&res  Odorantes  Artificielles,  par  George  F.  Jaubert,  Masson  et  Cie.,  Paris. 
1900. — Analyse  der  Harze,  Balsame,  etc.,  K.  Dieterich,  Berlin. 

India-rubber,  Gutta-percha,  and  Balata,  W.  T.  Brannt,  Philadelphia. 

Parfums  Comestibles,  par  George  F.  Jaubert,  Masson  et  Cie.,  Paris. 
1901. — Drying  Oils,  Boiled  Oil,  and  Solid  and  Liquid  Dryers,  L.  E.  Andes,  London. 
1903. — The  Chemistry  of  India  Rubber,  Carl  Otto  Weber,  London  and  Philadelphia. 
1904. — Die  Riechstoffe,  George  Cohn,  Vieweg  und  Sohn,  Braunschweig. 
1906. — Painter's  Colors,  Oils  and  Varnishes,  G.  H.  Hurst,  London. 

Die  Harze  und  die  Harzbehalter,  A.  Tschirch,  2te  Auf.,  2  Bde.,  Leipzig. 
1907. — Analysis  of  Mixed  Paints,  Color  Pigments,  and  Varnishes,  C.  D.  Holley  and 
E.  F.  Ladd. 

India  Rubber  and  its  Manufacture,  H.  L.  Terry,  London. 

Chemistry  and  Technology  of  Mixed  Paints,  M.  Toch,  New  York. 
1908. — The  Chemistry  of  Essential  Oils  and  Perfumes,  Ernest  J.  Parry,  2nd  Edition, 
D.  Von  Nostrand,  New  York. 

Die  Lack  und  Firniss-fabrikation,  Max  Bottler,  Wm.  Knapp,  Halle. 

Synthetische   und   Isolierte  Riechstoffe   und  deren  Darstellung,    Dr.   Rudolf 
Knoll,  Wm.  Knapp,  Halle. 

Die  Analyse  des  Kautschuks,  der  Gutta  Percha,  Balata  und  ihre  zuslitze,  bei 
Dr.  Rudolf  Detmar,  Hartleben,  Wien. 

Harze  und  Harz  Industrie,  Max  Bottler,  Hanover. 

1909. — Die  Fabrikation  der  Kopal,  Turpentinoel,  und  Spiritus-Lacke,  L.  E.  Andes, 
3te  Auf.,  Hartleben,  Wien. 

•L'Industrie  des  perfums  d'apres  les  theories  de  la  Chimie  Moderne,  M.  Otto, 
Paris. 

Theorie  der  gewinnung  und  Trennung  der  setherischen  oele  durch  destination, 

C.  von  Rechenberg,  Schimmel  £  Co.,  Leipzig. 

1910. — Die  J^therische  Oele,  von  E.  Gildermeister  und  Fr.  Hoffman,  2te  Auf.,   1st 
Bd.,  Schimmel  &  Co.,  Leipzig. 

Die    Kautchuk    und    seine    Priifung,  Hinrichsen  und   Memmler   S.   Hirzel, 
Leipzig.  N 

Handbuch  der  Lack  und  Firniss  Industrie,  F.  Seeligmann  und  E.  Zielke, 
Berlin. 

Die  JStherische  Oele,  R.  Leimbach,  Halle. 


BIBLIOGRAPHY  AND  STATISTICS. 


131 


STATISTICS. 

No  attempt  will  be  made  to  take  up  the  essential  oils  in  detail.  The 
statistics  of  the  entire  class  will  be  given,  and  only  a  few  of  the  more 
important  substances  will  be  specially  mentioned. 

Essential  Oils. — The  export  of  essential  oils  (bergamot,  lemon,  etc.) 
from  Sicily  and  Calabria  in  recent  years  has  been: 


Kilos. 

1903    864,770 

1904    1,006,103 

1905    868,244 

1906    948,328 

1907    1,056,898 


Value  in  lire. 

11,964,839 

14,758,590 

13,759,760 

18,556,053 

24,173,030 


The  Bulgarian  rose  oil  exportations  for  recent  years  have  been : 


1906. 

6700  kilos. 

Value  4,590,938  francs 


1907. 

3900  kilos. 
3,432,327  francs 


Peppermint  oil  is  exported  from  Japan  in  the  forms  of  menthol 
crystals  and  dementholized  oil.  The  statements  of  production,  there- 
fore, include  both  of  these  sources. 

The  exports  of  these  two  in  recent  years  have  been  as  follows: 


1904. 


Menthol    crystals    86,489  kilos. 

Value    $968,579 

Peppermint  oil    104,861  kilos. 

Value    $496,347 


1905.  1906. 

100,240  kilos.  57,329  kilos. 

$708,290  $459,287 

104,344  kilos.  72,682  kilos. 

$436,537  $329,872 


The  American  production  of  peppermint  oil  for  1907  was  estimated 
by  Schimmel  &  Co.  at  230,000  pounds,  of  which  New  York  furnished 
28,000  pounds  and  Michigan  and  Indiana  205,000  pounds. 

The  exports  of  cinnamon  chips,  for  the  extraction  of  oil  of  cinna- 
mon, from  Ceylon  in  recent  years  have  been : 


1901 1,516,083  pounds. 

1902 1,763,679   " 

1903 2,253,269   " 


1904 2,368,351  pounds. 

1905 2,325,514   " 

1906 2,531,614   " 


The  total  exports  of  chips  average  about  one-half  by  weight  of  the 
total  exports  of  Ceylon  cinnamon  bark.  The  world's  consumption  of 
bark  and  chips  together  during  the  last  few  years  has  been  in  round 
numbers  3,500,000  pounds  a  year. 

The  exports  of  citronella  oil  from  Ceylon  (Colombo  and  Galle)  have 
been  as  follows  in  recent  years: 


1904 1,156,646  pounds. 

1905 1,309,416       " 


1906 1,242,110  pounds. 

1907 1,312,192       " 

(Schimmel  &  Co.  Report,  April,  1908.) 


The  production  of  spirit  of  turpentine  in  the  United  States  amounts 
at  present  to  about  25,000,000  gallons,  of  a  value  of  about  $8,500,000. 


132          INDUSTRY  OF  THE  ESSENTIAL  OILS  AND  RESINS. 

The  exportations  of  turpentine  spirit  from  the  United  States  during 
the  five  years  stated  were: 

1903.  1904.  1905.  1906.  1907. 

Gallons    16,378,787     17,202,808     15,894,813     15,981,253     15,854,676 

Valued   at    ..   $8,014,322     $9,446,155     $8,902,101  $10,077,268  $10,241,883 

Camphor. — The  production  of  camphor  and  camphor  oil  in  greater 
Japan  (including  Formosa)  during  the  last  few  years  amounted  to: 

1905.  1906.  1907. 

Camphor    5,469,733  Ibs.         5,581,200  Ibs.         5,388,918  Ibs. 

Camphor    oil     ..  4,556,666    "  4,644,400    "  6,710,390    " 

The  export  of  camphor  in  1907  was  4,121,566  pounds,  valued  at 
5,026,858  yen.  The  production  of  camphor  in  China  is  given  as  follows  : 

1906.  1907. 

1,500,000  Ibs.  2,250,000  Ibs.    (to  end  of  August) 

The  world's  consumption  of  camphor  is  estimated  at  10,000,000 
pounds  yearly,  of  which  seventy  per  cent,  is  used  in  the  manufacture 
of  celluloid,  two  per  cent,  in  the  manufacture  of  gun  cotton,  fifteen 
per  cent,  for  disinfection,  and  thirteen  per  cent,  for  medicinal  uses. — 
Zeit.  fur  Angew.  Chemie,  1908,  p.  1201. 

Resins. — The  exportations  of  rosin  (colophony  resin)  from  the 
United  States  for  the  last  five  years  have  been  as  follows: 

1903.  1904.  1905.  1906.  1907. 

Barrels    2,396,498       2,585,108       2,310,275       2,438,556       2,560,966 

Valued  at    ..$4,817,205     $6,621,870     $7,069,084     $9,899,080  $11,327,091 

The  exports  of  button  lac  and  shellac  from  British  India  during 
recent  years  have  been  as  follows: 

Year  ending 
March  31, 1906.  To  March,  1907.  To  March,  1908. 

Pounds  29,053,920       27,153,392       35,580,832 

Value  $10,297,000      $11,152,286      $12,707,440 

The  importation  of  the  more  important  gums  and  resins  into  the 
United  States  during  the  past  five  years  has  been: 

1903.  1904.  1905.  1906.  1907. 

Crude  camphor    (Ibs.)    2,472,440     2,819,673     1,904,002     1,668,744     3,669,880 

Value    $764,400      $874,695      $638,744      $608,440  $1,932,073 

Chicle    (Ibs.)     4,282,247     5,084,580     5,060,166     5,828,641     6,768,470 

Value  $954,389  $1,308,540  $1,357,458  $1,657,587  $2,239,441 

Copal,  kauri,  and  dammar 

(Ibs.)  27,653,928  20,565,507  25,687,762  23,063,509  28,021,930 

Value  $2,938,754  $2,127,228  $2,493,438  $2,353,888  $3,126,737 

Shellac  (Ibs.)  11,590,725  10,933,413  10,700,817  15,937,763  18,418,135 

Value  $2,713,687  $3,505,229  $3,743,180  $5,200,449  $6,346,221 


BIBLIOGRAPHY  AND  STATISTICS. 


133 


An  estimate  of  the  annual  production  and  consumption  of  caout- 
chouc throughout  the  world  in  recent  years  is  as  follows : 


Production. 

1901-02  53,887  tons. 

1902-03  55,603 

1903-04  61,759 

1904-05  68,879 

1905-06  67,899 

1906-07  74,023 


Consumption. 

54,110  tons. 

55,276  " 

59,266  " 

65,083  " 

62,574  " 

68,173  " 


About  half  of  the  product  of  1907  was  Para  rubber. 

Gutta-percha. — The  entire  world's  production  of  gutta-percha  in 
1890  was  estimated  at  4,500,000  kilos.  This  amount  has  decreased  no- 
tably since  1890,  amounting  in  1896  to  only  2,600,000  kilos.,  and  in 
1901  to  2,400,000  kilos. 

The  United  States  importations  of  crude  caoutchouc  and  gutta- 
percha  with  related  substances  of  the  last  few  years  have  been: 

1905.  1906.  1907. 

Gutta-percha    (Ibs.)    665,217  500,770  546,890 

Value    $210,188  $188,161  $201,339 

Gutta-joolatong  (Ibs.)    19,104,911  21,390,116  28,437,660 

Value    $641,319  $733,074  $1,085,098 

India  rubber  (Ibs.)    67,234,256  57,844,345  76,963,838 

Value    $49,878,366  $45,114,450  $58,919,981 

India  rubber  scrap   (Ibs.)    15,575,214  24,756,486  29,335,193 

Value    $953,439  $1,721,678  $2,608,987 

The  exportation  of  balata  from  South  American  countries  in  recent 
years  has  been: 

1904.               1905.  1906.  1907. 

From  British  Guiana  (Ibs.)    ..   800,133       774,665  728,231  834,728 

Value    £66,996       £54,837  £53,011  £64,094 

From  Venezuela  (Ibs.)    1,232,148  1,455,973 

Value     £176,039  £224,414 

From  Dutch  Guiana  ( Ibs. )    . . .  259,000       244,000  270,000       

Value    £37,904      £34,630  £44,990       


134 


THE  CANE-SUGAR  INDUSTRY. 


CHAPTER    IV. 


THE    CANE-SUGAR    INDUSTRY. 

I.  Raw  Materials. 

ALTHOUGH  sucrose,  or  cane-sugar,  is  present  in  a  great  many  plants, 
it  is  usually  accompanied  by  relatively  large  quantities  of  other  carbo- 
hydrates, such  as  glucose,  starch,  etc.;  so  that  its  extraction  on  a  com- 
mercial scale  is  practically  impossible.  In  order  to  extract  the  cane-sugar 
advantageously,  glucose,  invert  sugar,  and  other  dissolved  solids  must 
not  be  present  in  amount  relatively  large  as  compared  with  the  sucrose. 
If  this  ratio  of  sucrose  to  total  dissolved  solids,  called  the  "coefficient 
of  purity,"  falls  below  a  certain  percentage  (usually  put  at  sixty-five), 
the  plant-juice  cannot  be  economically  worked  for  the  extraction  of 
crystallized  cane-sugar.  At  the  present  time  the  sucrose  is  extracted 
from  four  different  sources,  and  on  what  may  be  termed  a  commercial 
scale  from  two  only. 

1.  THE  SUGAR-CANE. — The  sugar-cane  belongs  to  the  family  of 
grasses,  growing,  however,  to  an  exceptionally  large  size.  The  plant  is 
known  as  Saccliarum  officinarum,  and  the  best  known  varieties  are  called 
by  guch  names  as  Bourbon  cane,  Otaheite  purple  cane,  ribbon  cane,  crys- 
talline cane,  and  Java  cane.  It  has  a  wide  range,  succeeding  in  almost 
all  tropical  and  sub-tropical  countries,  and  requires  a  warm,  moist 
climate,  developing  most  luxuriantly  on  islands  and  sea-coasts  in  the 
tropics.  It  is  the  richest  in  sugar  of  all  the  plants  cultivated  for  this 
purpose.  Under  ordinary  favorable  conditions  it  yields  about  ninety 
per  cent,  of  juice,  which  contains  eighteen  to  twenty  per  cent,  of  crys- 
tallizable  cane-sugar.  The  following  analyses  of  sugar-canes  from  sev- 
eral sources  illustrate  its  composition: 


Martinique. 
(Peligot.) 

Guadeloupe. 
(Dupuy.) 

Mauritius, 
(leery.) 

Martinique. 
(Popp.) 

MiddleEgypt. 
(Popp.) 

Upper  Egypt. 
(Popp.) 

Water  .  . 
Sucrose  .  . 
Glucose 

72.1 
18.0 

72.0 
17.8 

69.0 
20.0 

72.22 
17.80 
0.28 

72.15 
16.00 
2.30 

72.13 
18.10 
0.25 

Cellulose  . 
Salts  .  .  . 

f    9.9 

9.8 
0.4 

10.0 
0.7  to  1.2 

9.30 
0.40 

9.20 
0.35 

9.10 
0.42 

100.00 

100.00 

99.  7  to  100.2 

100.00 

100.00 

100.00 

The  most  successful  cultivation  of  the  sugar-cane  is  at  present  car- 
ried on  in  Cuba  and  other  West  Indian  islands,  and  on  the  irrigated, 
fertile,  volcanic  soils  of  Hawaii. 


RAW  MATERIALS. 


135 


2.  SUGAR-BEET. — The  sugar-beet  is  a  source  of  sucrose  that,  while 
first  mentioned  as  long  ago  as  1747,  when  Marggraf  called  the  attention 
of  the  Berlin  Academy  of  Sciences  to  its  importance  as  a  sugar-yielding 
material,  has  only  in  the  last  few  decades  advanced  to  great  importance 
and  taken  position  as  a  successful  rival  of  the  sugar-cane  in  the  matter 
of  production.  It  has  been  greatly  improved  by  careful  selection  and 
cultivation,  and  its  richness  in  sugar  notably  increased.  Marggraf  could 
only  extract  6.2  per  cent,  of  sugar  from  the  white  and  4.5  per  cent, 
from  the  red  beet;  it  has  now  been  brought  to  an  average  of  eleven  per 
cent.,  and  in  exceptional  cases  has  been  found  to  contain  eighteen  per 
cent.  Some  six  varieties  are  now  cultivated  in  Germany,  where  the 
beet-sugar  industry  has  reached  its  highest  development:  the  white 
Silesian,  the  Quedlinburg,  the  Siberian,  the  French,  the  Imperial,  and 
the  Electoral.  (The  beet  is  relatively  much  more  complex  in  its  chem- 
ical composition  than  the  sugar-cane,  and  the  expressed  juice  contains 
a  number  of  organic  impurities  not  present  in  the  juice  of  the  cane, 
notably  of  the  class  of  nitrogenous  or  albuminoid  substances.  On  the 
other  hand,  glucose,  or  invert  sugar,  which  is  frequently  present  in  the 
cane,  is  practically  absent  in  the  juice  of  fresh  beets.)  The  detailed 
composition  of  the  sugar-beet  is  seen  from  the  accompanying  scheme  of 
Scheibler.*  At  the  same  time  the  three  accompanying  analyses  by  R. 
Hofmann  give  the  composition  of  three  types  of  beets:  those  poor  in 
sugar,  those  of  medium  richness,  and  those  containing  the  largest  per- 
centage. 


First  type. 

Second  type. 

Third  type. 

Water  

8920 

83.20 

75.20 

4.00 

9.42 

15.00 

1.00 

1.64 

2.20 

4.13 

3.34 

4.23 

1.01 

1.50 

2.07 

Ash   

0.66 

0.90 

1.30 

100.00 

100.00 

100.00 

3.  SORGHUM  PLANT. — The  sorghum  plant  (Sorghum  saccharatum 
and  other  species)  has  been  known  and  valued  in  China  for  ages,  and 
small  quantities  have  been  cultivated  in  the  United  States  for  the  sake 
of  the  syrup  for  a  number  of  years  past.  It  is  only  of  recent  years, 
however,  that  attention  has  been  drawn  to  it  as  a  source  of  crystallized 
sugar,  chiefly  by  the  experiments  of  the  United  States  Bureau  of  Agri- 
culture, and  its  systematic  cultivation  has  been  attempted  in  several 
parts  of  the  United  States.  The  composition  and  saccharine  strength 
of  the  juice  seem  to  be  quite  variable,  and  dependent  upon  conditions 
of  cultivation  to  a  much  greater  extent  than  is  the  case  with  either  the 
sugar-beet  or  the  sugar-cane.  Thus,  in  1883  the  mean  per  cent,  of 


*  Bericht  iiber  Entwick  Chem.  Ind.,  von  Hofmann,  1877,  3te  Heft,  p.  187. 


136 


THE  CANE-SUGAR  INDUSTRY. 


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RAW  MATERIALS. 


137 


sucrose  in  the  sorghum  juice,  analyzed  by  the  chemists  of  the  depart- 
ment, was  8.65,  in  1884  the  mean  was  14.70  per  cent.,  in  1885  it  was 
9.23,  and  in  1886  it  was  8.60  per  cent.  The  sorghum  plant  grows  easily 
over  a  very  wide  range  of  climate,  and  if  its  cultivation  can  be  estab- 
lished definitely  upon  correct  principles,  it  may  prove  to  be  a  most  valu- 
able addition  to  the  world's  sugar-producing  materials. 

4.  THE  SUGAR-MAPLE. — The  sap  of  Acer  saccharinum  and  other 
species  of  the  genus  Acer  is  a  source  of  sugar  and  syrup  more  esteemed 
for  confectionery  and  table  use  than  because  of  its  commercial  import- 
ance. The  sugar  is  never  refined,  and  only  comes  into  use  as  a  raw, 
small-grained  sugar  of  peculiar  and  characteristic  flavor;  the  syrup  is 
a  thin,  sweet  syrup  of  the  same  characteristic  maple  flavor,  differing 
considerably,  too,  in  its  composition  from  both  cane-  and  beet-sugar 
syrups.  The  freshly-collected  sap  contains  from  two  to  four  per  cent, 
of  sucrose,  with  traces  of  glucose. 

"We  may  now  compare  the  chemical  composition  of  the  freshly-ex- 
pressed juice  from  the  three  sources  of  sugar  manufacture  above  de- 
scribed, and  note  those  differences  which  are  of  importance  in  deter- 
mining the  successful  extraction  and  crystallization  of  the  cane-sugar. 

The  composition  of  the  fresh  juice  of  the  sugar-cane  is  illustrated  in 
the  following  table.  The  first  four  analyses  are  by  the  United  States 
Bureau  of  Agriculture  and  were  made  in  connection  with  its  experi- 
mental work,  and  the  last  six  from  experimental  cultivation  of  certain 
varieties  of  cane  in  Cuba  on  the  Soledad  estate  of  Mr.  E.  Atkins. 


LOUISIANA. 

CUBA. 

1884. 

1885. 

1886. 

1887. 

Crystalline 
cane. 

Red  ribbon 
cane. 

Black  Java 
cane. 

Specific  gravity  . 
Total  solids  .  .  . 
Sucrose  

1.068 
16.54 
13.05 
0.67 

0.19 
78.97 

islso 

12.11 
1.02 

0.16 
76.64 

1.066 
16.20 
13.50 
0.61 

0.167 
83.33 

1.066 
16.37 
13.69 
0.77 

83.48 

11.6°  B. 
20.9 
19.2 
0.66 
Non- 
sugar. 
1.04 

91.8 

12.5°  B. 
22.6 
20.5 
0.20 
Non- 
sugar. 
1.90 

90.7 

11  2°  B. 

20.2 
18.5 
0.14 
Non- 
sugar. 

91.5 

12.1°  B. 
21.9 
20.0 
0.31 
Non- 
sugar. 
1.69 

91.3 

12.2°  B. 
22.0 
21.3 
Trace. 
Non- 
sugar. 
0.70 

96.8 

11.8°  B. 
21.4 
20.6 
0.08 
Non- 
sugar. 
0.71 

96.3 

Glucose  

Albuminoids  .  . 
Coefficient  of 

It  will  be  seen  that  under  favorable  conditions  the  sucrose  percentage 
in  cane-juice  may  rise  to  over  20  per  cent. 

The  average  composition  of  the  fresh  beet  juice  is  shown  in  the  fol- 
lowing analyses,  the  method  of  obtaining  the  juice  being  also  indicated. 
The  first  four  are  from  "Stammer's  Lehrbuch, "  and  represent  each  of 
the  average  of  a  German  beet-sugar  factory  for  the  season;  the  fifth  is 
from  beets  cultivated  at  Washington,  D.  C.,  by  the  Bureau  of  Agri- 
culture; the  sixth  the  average  of  a  week's  work  at  Alvarado,  California, 
in  1888,  and  the  last  from  a  beet  grown  at  Grand  Island,  Nebraska,  and 
analyzed  at  the  State  Agricultural  Experiment  Station. 


138 


THE  CANE-SUGAR  INDUSTRY. 


German. 
By  press- 
ure. 

German. 
By  diffu- 
sion. 

German. 
By    cen- 
trifugat- 
ing. 

German. 
By    ma- 
ceration. 

Washing- 
ton. 
By  press- 
ure. 

Alvarado, 
Cal. 
By    diffu- 
sion. 

Grand 
Island,  Neb.* 
H.H.Nichol- 
son. 

Total  solids  (degree 
Brix.)     

16.27 

17.20 

14.99 

18.77 

11.78 

17.20 

23.70 

Sucrose  .       .... 

1302 

14.63 

11.98 

14.64 

7.61 

14.80 

21.41 

0.39 

0.138 

Non-sugar    .... 
Coefficient  of  purity 

3.25 
80.02 

2.57 
85.14 

3.01 
79.92 

4.13 
77.99 

3.78 
64.60 

2.4 

85.5 

2.152 
90.3 

In  1907,  at  one  factory  in  California  (Los  Alamitos)  the  average 
for  the  entire  campaign  was :  sugar,  19.3  per  cent.,  with  an  average  co- 
efficient of  purity  of  84.8. 

The  composition  of  the  sorghum  juice  of  different  seasons,  as  culti- 
vated by  the  United  States  Department  of  Agriculture,  is  shown  in  the 
following  table: 


1883. 

1884. 

1885. 

1886 

18 

87. 

Fort  Scott. 

Rio  Grande. 

Total  solids   

13.59 

19.75 

1507 

17  08 

16  14 

1402 

8.65 

14.70 

9.23 

9.59 

9.54 

898 

Glucose  «.... 

4.08 

1.27 

3  04 

4.25 

3  40 

3  24 

0.86 

3.78 

2.80 

3.24 

3  20 

1.80 

Coefficient  of  purity   

63.65 

74.43 

61.25 

56.15 

59  11 

64.05 

Analyses  of  fresh  maple-sap  made  at  Lunenburg,  Vermont,  by  one 
of  the  chemists  of  the  Department  of  Agriculture,  in  the  spring  of  1885, 
show  that  it  contains  an  average  of  3.50  per  cent,  of  sucrose,  traces  only 
of  glucose,  about  .01  per  cent,  of  albuminoids,  and  has  a  mean  coefficient 
of  purity  of  95. 

n.  Processes  of  Treatment. 

1.  PRODUCTION  OF  SUGAR  PROM  THE  SUGAR-CANE. — As  the  cultiva- 
tion of  the  sugar-cane  is  chiefly  carried  on  in  the  tropical  countries, 
parts  of  which  are  dependent  upon  totally  unskilled  labor,  there  is  very 
great  diversity  in  the  development  which  the  industry  has  reached. 
In  some  countries  the  work  is  still  done  by  hand  or  with  the  simplest 
kind  of  machinery,  with  corresponding  small  yield  of  inferior  products, 
while,  in  others,  as  in  Louisiana,  Demerara,  Cuba  and  other  West  Indian 
islands,  there  are  many  sugar  plantations  equipped  with  the  very  latest 
and  best  of  sugar-making  machinery,  and  producing  direct  from  the 
juice  raw  sugars  that  are  almost  equal  to  the  refined  product.  In  gen- 
eral, however,  the  sugars  produced  on  the  plantation  are  not  in  a  suffi- 
ciently pure  condition  for  consumption  and  are  termed  "raw  sugars," 
having  therefore  to  undergo  a  process  of  refining,  by  which  the  impuri- 
ties are  eliminated  and  the  sucrose  obtained  in  a  r pure,  well-crystallized 
state.  "We  shall  note  first  the  method  of  producing  raw  sugar,  and 
afterwards  the  methods  of  refining  the  same  at  present  in  use. 

*  Individual  beets  grown  in  Nebraska  have  shown  a  percentage  of  22.08  sucrose, 
and  a  coefficient  of  purity  of  ninety-three  per  cent. 


PROCESSES  OF  TREATMENT. 


139 


The  canes  must  be  cut  when  they  have  arrived  at  maturity,  and 
must  be  promptly  used  to  prevent  the  fermentation  of  the  albuminoid 
constituents  and  other  non-sugar  of  the  cane,  which  in  turn  rapidly 
changes  sucrose  into  invert  sugar  and  lessens  the  possible  yield  of  crys- 
tallizable  sugar.  At  least  this  immediate  use  of  the  cut  cane  is  necessary 
in  Cuba,  Demerara,  and  distinctly  tropical  countries,  where  the  juices 
must  be  expressed  within  forty-eight  hours  after  the  cutting  to  prevent 
an  excessive  inversion  taking  place.  In  Louisiana,  the  experiments  of 
the  Department  of  Agriculture  have  shown*  that  sound  canes  can  be 
kept  stored  under  cover  for  two  or  three  months  without  appreciable 
diminution  in  the  sucrose  per  cent,  or  loss  in  the  coefficient  of  purity. 

The  expression  of  the  juice  has  been,  and  in  most  cases  still  con- 
tinues to  be,  effected  by  the  process  of  crushing  the  canes  between  heavy 
rolls,  which  may  vary  from  the  crude  stone  or  iron  rolls,  driven  by  water 
or  horse-power,  to  the  perfected  sugar-mills  now  in  use,  in  which  enor- 

FIQ.  35. 


mous,  hollow,  steam-heated  rolls,  driven  by  steam,  are  used  to  do  the 
same  work.  Large,  slow-moving  rolls  have  been  found  in  practice  to 
yield  better  results  than  smaller,  rapid-moving  rolls.  While  four,  five, 
and  even  nine-roll  mills  have  been  constructed,  the  mill  in  general  use 
is  a  three-roll  mill,  an  example  of  which  is  shown  in  Fig.  35.  The  canes 
pass  by  the  carrier,  down  the  slide,  through  the  rolls,  and  the  "  bagasse  " 
(exhausted  canes)  emerging  below  is  carried  away  for  fuel  purposes, 
while  the  juice  as  expressed  collects  in  a  receptacle  and  is  run  to  the 
evaporators. 

While  the  analyses  of  sugar-canes,  given  on  a  previous  page,  show 
that  the  cane  contains  ninety  per  cent,  of  juice,  the  percentage  of  ex- 
traction of  juice  by  this  roller-crushing  process  on  the  best-managed 
Cuban  estates  does  not  exceed  seventy  or  seventy-one,  and  generally 
ranges  from  sixty  to  sixty-five,  per  cent.  This  imperfect  liberation  of 

*  Bulletin  No.  5,  p.  57. 


140 


THE  CANE-SUGAR  INDUSTRY. 


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PROCESSES  OF  TREATMENT.  141 

the  cane  juice  by  the  crushing  process  has  led  to  experiments  in  other 
directions.  One  result  has  been  the  frequent  introduction  of  a  second 
or  supplementary  crushing  of  the  cane  in  a  two-roll  mill  following  the 
use  of  the  three-roll  mill  before  described.  These  second  rolls  are 
heavier,  and  the  pressure  is  greater  than  in  the  first  crushing.  The 
total  percentage  of  juice,  and  consequently  of  sugar  extracted  from  the 
cane,  is  raised,  although  the  juice  from  the  second  and  heavier  pressure 
is  less  rich  in  sucrose  than  the  first  juice,  which  came  from  the  softer 
pulp  of  the  cane. 

It  has  also  been  sought  to  increase  the  yield  of  saccharine  juice  by 
submitting  the  cane  to  the  action  of  hot  water  or  steam  at  an  inter- 
mediate stage  between  the  two  crushings.  It  is  stated  that  a  "macera- 
tion "  process  of  this  kind,  known  as  Duehassing 's,  has  been  in  quite 
successful  use  in  Guadeloupe,  raising  the  yield  of  sugar  from  9.40  per 
cent,  on  the  cane  to  11.04  per  cent. 

All  the  processes  hitherto  described  for  extracting  the  juice  from 
the  cane  have  depended  for  success  upon  the  rupture  of  the  juice-con- 
taining cells.  ''Diffusion,"  which  has  been  so  successful  in  the  extrac- 
tion of  the  juice  of  the  sugar-beet,  differs  from  them  essentially  in  dis- 
pensing with  the  breaking  up  of  the  cells,  and  in  substituting  therefor 
a  displacement  by  osmosis  or  diffusion  of  the  saccharine  juice  by  pure 
water.  As  a  description  of  this  method  follows  when  speaking  later  of 
the  treatment  of  the  sugar-beet,  we  will  at  this  stage  speak  only  of  the 
advantages  and  disadvantages  of  its  application  to  the  sugar-cane  work. 
It  has  not  met  at  all  with  general  favor  from  sugar-cane  planters.  Dif- 
ficulties were  met  with  in  cutting  the  chips  needed  for  the  diffusion- 
cells.  The  sugar-cane  differs  so  radically  in  its  structure  from  the 
sugar-beet  that  totally  different  forms  of  slicing  apparatus  had  to  be 
used.  The  cane-chips  tended  to  pack  in  the  cells,  and  so  impeded  the 
circulation  of  the  warm  water.  When  this  took  place,  fermentation  and 
inversion  of  the  sucrose  rapidly  followed.  The  cane-chips,  after  ex- 
haustion, do  not  make  as  good  a  fuel  as  the  bagasse  of  the  cane-mill. 
The  first  of  these  difficulties  has  been  overcome  both  in  the  use  of  dif- 
fusion apparatus  in  Guadeloupe  and  by  the  United  States  Department 
of  Agriculture  in  its  experiments  on  diffusion,  as  applied  to  the  sugar- 
cane made  at  Fort  Scott,  Kansas,  in  1886.  The  second  difficulty  has  in 
part  been  overcome  by  using  hotter  diffusion  water  (at  90°  C.),  and 
working  more  rapidly  with  a  sufficient  pressure.  But  it  is  more  effect- 
ually prevented  by  the  use,  in  the  diffusion-cells,  of  either  carbonate  of 
lime,  as  proposed  and  patented  by  Professor  M.  Swenson,  or  of  dry- 
slacked  lime,  as  proposed  by  Professor  H.  W.  Wiley,  the  chemist  of  the 
Department  of  Agriculture.  Of  these,  the  latter  seems  to  meet  with 
more  general  approval  of  those  who  have  tried  diffusion  with  either  the 
sugar-cane  or  the  sorghum-cane.  In  answer  to  the  third  difficulty,  it  is 
remarked  that  the  bagasse  burns  better  largely  because  of  the  notable 
quantity  of  sugar  left  in  it,  and  that  when  the  diffusion-chips  are  dried 
they  will  burn  fairly.  They  can  also  be  used  to  great  advantage  for 
paper  stock  and  for  manure,  as  they  still  contain  most  of  the  nitro- 


142  THE  CANE-SUGAR  INDUSTRY. 

genous  constituents  of  the  cane.  On  the  other  hand,  if  successfully 
carried  out,  it  undoubtedly  effects  a  more  complete  extraction  of  the 
sugar  than  any  other  process.  At  Monrepos.,  Guadeloupe,  with  Bous- 
caren's  apparatus,  consisting  of  six  diffusors,  juice  having  a  density 
nearly  equal  to  that  of  the  natural  juice  is  obtained,  one  and  a  half 
hours  being  sufficient  for  extracting  the  sugar.  The  yield  of  white 
sugar  amounts  to  twelve  and  a  half  to  thirteen  per  cent,  of  the  weight 
of  the  cane.*  At  Fort  Scott,  Kansas,  the  chemists  of  the  Department 
of  Agriculture,!  in  their  experiments  with  diffusion  as  applied  to  sugar- 
canes,  succeeded  in  obtaining  a  yield  the  highest  ever  got  from  sugar- 
cane. The  mean  loss  of  sugar  in  the  chips  at  Fort  Scott  was  .38  per 
cent.,  and  the  quantity  of  sugar  present  was  9.56.  The  percentage  of 
extraction  was,  therefore,  ninety-six  per  cent.,  or,  reckoned  on  the 
weight  of  cane,  86.4  per  cent,  of  a  possible  ninety,  which,  if  compared 
with  the  best  figures  obtained  in  mill-crushing  shows  a  decided  advan- 
tage for  diffusion. 

The  treatment  of  the  expressed  juice  is  next  to  be  noted.  This  has 
also  undergone  considerable  improvement  in  recent  years,  although  on 
small  isolated  sugar  plantations  the  primitive  and  wasteful  methods  of 
the  "copper- wall,"  or  open-pan,  boiling  are  still  in  use.  The  general 
outline  of  the  treatment  of  the  juice  which  is  followed  in  the  main,  if 
not  always  in  detail,  is  given  in  the  accompanying  scheme. 

The  juice  of  the  sugar-cane  must  be  properly  ' '  defecated, ' '  or  treated 
with  milk  of  lime,  in  order  to  neutralize  the  organic  acids  of  the  juice, 
and  so  prevent  their  starting  a  fermentation  and  consequent  inversion 
of  the  sucrose  when  the  juice  is  heated.  This  has  the  effect,  as  soon  as 
the  juice  is  heated,  of  bringing  to  the  surface  a  thick  scum  of  lime  salts, 
holding  mechanically  entangled  much  of  the  albuminoids  and  suspended 
particles  of  fibre  of  the  juice.  This  is  known  as  the  "blanket-scum." 
This  is  removed  by  skimming,  and  the  boiling  continued,  when  addi- 
tional greenish  scum  forms,  which  is  similarly  removed.  When  the 
scum  ceases  to  form,  the  steam  is  shut  off  and  the  sediment  allowed  to 
settle,  and  the  clarified  juice  gradually  drawn  off.  The  amount  of  lime 
to  be  added  in  the  case  of  cane  juice  is  usually  .2  to  .3  per  cent.,  or  about 
four  ounces  of  quicklime  to  the  gallon  of  juice,  but  is  always  carefully 
controlled,  so  that  the  acids  of  the  juice  are  not  entirely  neutralized 
and  a  faint  acid  reaction  still  remains.  Should  the  lime  be  in  excess, 
the  glucose  almost  always  present  in  the  cane  juice  is  rapidly  acted  upon 
and  decomposed,  yielding  dark-colored  products.  An  excess  of  lime  is 
always  corrected  before  further  treatment  by  the  addition  of  sulphur- 
ous, sulphuric,  or  phosphoric  acids.  In  the  older  process  of  open-pan 
boiling,  this  defecating  and  clarifying  takes  place  in  the  first  of  five 
connected  kettles  or  pans,  walled  in  and  heated  by  the  same  fire,  and 
known  technically  as  the  "copper-wall."  From  this  first  pan  the  juice, 
after  the  removal  of  the  blanket-scum,  goes  to^the  second,  in  which  it 
receives  more  heat.  After  it  is  thoroughly  clarified  and  both  scum  and 
sediment  removed,  the  juice  goes  to  the  third  and  fourth  pans  succes- 

*  Spon's  Encyclopedia,  p.  1881.  t  Bulletin  No.  14,  p.  53. 


PROCESSES  OF  TREATMENT. 


143 


sively,  in  which  it  is  concentrated  to  30°  B.,  and  then  goes  to  the  fifth, 
or  "strike-pan,"  to  be  brought  to  the  crystallizing  point.  When  the 
"masse-cuite,"  full  of  separating  crystals,  has  been  sufficiently  heated, 

Fia.  36. 


it  is  "struck  out  "  into  shallow,  crystallizing  vessels  and  allowed  to 
cool,  and  so  complete  the  crystallization.  The  older  open-pan  sugars 
are  generally  "cured,"  or  freed  from  syrup,  simply  by  draining  in 


144  THE  CANE-SUGAR  INDUSTRY. 

vessels  with  perforated  bottoms,  or,  in  a  limited  number  of  cases,  by 
the  process  of  "claying,"  or  covering  the  sugar  in  cones  with  a  batter 
of  clay  and  water,  through  which  water  percolates,  slowly  displacing 
the  darker  syrup.  The  first  method  gives  the  common  "muscovado  " 
sugar,  a  moist,  brown  sugar,  which  goes  from  the  West  Indies  to  the 
United  States  and  Europe  for  refining;  the  second  method  gives  a 
lighter-colored  but  soft-grained  sugar,  which  similarly  must  be  refined 
for  use.  This  older  and  cruder  method  has  given  place  most  generally 
now  to  improved  methods,  whereby  the  yield  is  notably  increased  and 
grades  of  raw  sugars  are  produced  that  are  much  purer  and  finer  in  ap- 
pearance. The  chief  improvements  consist  in  the  use  of  vacuum-pans  for 
concentration  of  the  juice  and  centrifugals  for  curing  the  crystallized 
sugar.  At  the  same  time  other  minor  improvements  contribute  no  little 
to  the  better  results.  The  juice,  unless  it  has  been  gotten  by  diffusion, 

FIG.  37. 


is  generally  run  through  a  strainer  into  the  clarifier.  In  addition  to 
very  careful  and  exact  measuring  of  the  amount  of  "temper-lime  " 
needed,  sulphurous  acid  or  phosphoric  acid  are  added  to  the  juice,  fol- 
lowed by  lime  until  the  juice  is  nearly  neutralized.  On  heating  the 
juice  becomes  bright  and  thin,  most  of  the  gummy  impurities  being 
removed  by  this  treatment.  It  may  be  passed  through  bag  filters  and 
is  then  ready  for  the  vacuum  pan. 

Much  raw  sugar  obtained  by  the  use  of  sulphuring  and  vacuum-pan 
evaporation  is  well  crystallized  and  nearly  white  and  can  be  brought 
into  use  without  refining  or  bone-black  filtration. 

The  most  important  improvement  in  the  preparing  of  a  better-grade 
sugar,  however,  consists  in  the  use  of  the  vacuum-pan,  by  means  of 
which  the  concentration  can  be  effected  with  the  least  heating,  and 
hence  least  discoloring  of  the  sugar-containing  juice.  The  vacuum-pan, 
invented  in  1813  in  England  by  Howard,  allows  of  the  concentration, 


PROCESSES  OF  TREATMENT. 


145 


or  "boiling  to  grain,"  being  effected  at  temperatures  varying  from  130° 
to  170°  or  180°  F.,  instead  of  the  240°  or  250°  F.  reached  in  the  open- 
pan.  They  are  of  varying  forms,  but  consist  essentially  of  a  spherical, 
cylindrical,  or  dome-shaped  copper  or  iron  vessel,  such  as  is  shown  in 
Fig.  36.  The  contents  of  this  vessel  are  heated  by  the  steam-coils  shown 
in  the  cut,  and  the  vacuum  is  maintained  by  the  connection  with  an 
injector  air-pump,  as  shown.  The  vacuum-pan  is  connected  first  with 
an  overflow  vessel,  or  "save-all,"  to  collect  saccharine  juice  thrown 
over,  and  thence  with  the  exhaust-pump.  Through  suitable  openings 
in  the  side  of  the  pan  the  interior  can  be  illuminated  and  the  operations 
watched;  samples  can  be  withdrawn  by  the  aid  of  the  "proof-stick  " 
for  examination,  and  fresh  juice  can  be  admitted  when  the  grain  is  to 
be  built  up. 

In  concentrating  the  raw  juice,  considerable  use  is  made  of  what  are 
called  "mutiple  effect  "  vacuum-pans,  a  series  of  connected  pans  as 
shown  in  Fig.  37,  in  the  first  of  which  the  thin  juice  boils  under  a 
slightly-reduced  pressure  and,  of 
course,  at  a  slightly  lower  tem- 
perature than  in  the  air;  the 
vapor  from  the  boiling  juice  here 
passes  into  the  steam-drum  of  the 
second  pan,  and  readily  boils  the 
liquor  here,  which,  though  denser, 
is  under  a  greater  vacuum,  and 
similarly  the  vapor  from  this 
liquor  boils  the  most  concentrated 
juice  in  the  third  pan,  in  which, 
by  the  aid  of  the  condensing- 
pump,  a  very  perfect  vacuum  is 
maintained.  Thus  large  quanti- 
ties of  juice  are  evaporated  with  great  economy  of  fuel.  These  triple 
effects  have  been  much  improved  in  the  last  few  years  by  the  modifica- 
tions introduced  by  Yaryan  and  Lillie,  both  of  whom  adopt  the  plan  of 
sending  the  sugar  juice  to  be  concentrated  through  the  series  of  coils 
while  the  steam  circulates  around  these  tubes.  The  action  of  the  Yaryan 
apparatus  will  be  understood  from  Fig.  38,  giving  a  simplified  section 
through  one  of  the  pans  and  "catch-alls."  The  heating-tubes,  sur- 
rounded by  steam,  are  divided  into  units  or  sections,  consisting  of  five 
tubes  coupled  at  the  ends  so  as  to  form  one  passage.  Of  such  sections 
there  may  be  any  number.  The  liquor  enters  the  first  tube  of  the  coil 
in  a  small  but  continuous  stream,  and  immediately  begins  to  boil  vio- 
lently. It  is  thus  formed  into  a  mass  of  foam,  which  contains,  as  it 
rushes  along  the  heated  tubes,  a  constantly-increasing  portion  of  steam. 
The  mixture  is  thus  propelled  forward  at  a  high  velocity,  and  finally 
escapes  into  an  end  chamber  known  as  a  "  separator, ' '  which  is  provided 
with  baffle-plates. 

The  "masse-cuite  "  having  been  brought  to  sufficient  thickness,  the 


10 


146  THE  CANE-SUGAR  INDUSTRY. 

whole  or  a  part  of  the  contents  of  the  pan  are  ' '  struck-off . "  If  half 
the  contents  of  the  pan  are  discharged  and  fresh  syrup  then  admitted 
to  be  concentrated,  the  crystals  obtained  at  first  grow  by  the  deposit 
from  the  new  portion  of  syrup.  This  process  of  admitting  successive 
portions  of  fresh  syrup  after  the  "grain  "  has  once  formed  is  used  in 
the  development  of  large  crystals.  It  must  be  used  with  judgment 
though,  or  the  new  syrup  starts  a  new  set  of  minute  crystals,  making 
what  is  called  ' '  false  grain. ' '  The  large  yellow  Demerara  crystals  are 
given  the  light  yellow  bloom  by  admitting  sulphuric  acid  in  small 
amount  after  the  grain  is  complete  and  just  before  the  "strike."  It 
destroys  the  gray-green  color  of  the  raw-sugar  crystals  and  gives  instead 
a  pale  straw  color. 

After  the  ' '  masse-cuite  "  has  left  the  pan,  the  crystallization,  except 
in  the  case  of  the  large  crystals,  is  -completed  by  cooling,  and  the  sugar 
must  then  be  "cured."  This  is  now  generally  effected  in  centrifugals 
or  rotary  perforated  drums.  A  form  in  common  use  for  sugar-work  is 
shown  in  Fig.  39.  Over  each  centrifugal  is  a  discharge-pipe  from  the 
coolers;  the  brown  or  yellow  magma  is  let  in,  the  inner  drum  is  started 
revolving,  and  the  mass  heaping  against  the  perforated  sides  becomes 
rapidly  lighter  in  color  as  well  as  more  compact ;  the  syrup  flies  off,  and 
from  the  space  between  the  inner  and  outer  drums  runs  off  below  into 
the  proper  receptacle.  The  centrifugal  is  emptied  through  the  bottom 
of  the  drums  by  raising  the  central  spindle  and  with  it  the  detachable 
plates  around  it,  so  that  a  circular  opening  is  made  in  the  middle  of  the 
apparatus. 

A  serious  loss  of  sugar  in  the  usual  method  of  working  is  in  the 
scums,  which  are  frequently  thrown  away.  Professor  Wiley,  the 
chemist  of  the  Department  of  Agriculture,  has  shown*  that  in  working 
a  crop  of  9063  tons  of  cane  the  loss  of  sugar  in  the  scums,  if  thrown 
away,  would  have  amounted  to  120,316  pounds,  of  which  94,545  pounds 
would  have  gone  in  the  blanket-scums,  and  25,771  pounds  in  the  sub- 
sequent scums.  To  save  this  sugar,  the  scums  are  steamed  and  then 
pressed  and  washed  in  a  filter-press  (see  p.  157),  whereby,  practically, 
the  whole  of  the  sugar  can  be  recovered.  The  scums  are  generally 
filter-pressed  now  in  the  best  Cuban  and  Louisiana  sugar-houses,  al- 
though a  cruder  method  of  pressing  them  in  bags  is  used  on  some  plan- 
tations. The  application  to  cane-juice  of  the  method  so  generally  fol- 
lowed in  the  case  of  beet-sugar  of  adding  an  excess  of  lime,  which,  after 
the  first  boiling  up,  is  removed  by  the  process  of  carbonatation  or  satu- 
rating with  carbonic  acid  gas,  has  generally  been  considered  to  be  impos- 
sible, because,  as  was  stated  before,  an  excess  of  lime  acts  injuriously 
upon  any  glucose  present  and  darkens  the  juice.  But  if  the  juice  is 
from  sound  canes  in  which  the  glucose  percentage  is  not  large,  the  ad- 
vantages of  the  carbonatation  process  may  exceed  the  injurious  effects. 
This  seems  to  have  been  shown  by  the  experiments  of  the  Department 
of  Agriculture  at  Fort  Scott,  Kansas,  in  the  fall  of  1886. f  The  yield 
of  sugar  in  the  experiments  in  which  both  diffusion  and  carbonatation 
*  Bulletin  of  Department  of  Agriculture,  Xo.  5,  p.  59.  t  Ibid.,  No.  14,  pp.  52  and  53. 


PROCESSES  OF  TREATMENT. 


147 


were  followed  was,  as  mentioned  before,  larger  than  had  ever  been 
gotten  from  sugar-canes.  Professor  Wiley  sums  up  the  advantages  of 
the  process  as  follows:  "The  process  of  carbonatation  tends  to  increase 
the  yield  of  sugar  in  three  ways:  (1)  It  diminishes  the  amount  of  glu- 
cose. This  diminution  is  small  when  the  cold  carbonatation,  as  practised 


at  Fort  Scott,  is  used;  yet  to  at  least  one  and  a  half  its  extent  it  in- 
creases the  yield  of  crystallized  sugar.  (2)  By  the  careful  use  of  the 
process  of  carbonatation  there  is  scarcely  any  loss  of  sugar.  The  only 
place  where  there  can  be  any  loss  at  all  is  in  the  press-cakes,  and  when 
the  desucration  of  these  is  properly  attended  to  the  total  loss  is  trifling. 
The  wasteful  process  of  skimming  is  entirely  abolished,  and  the  in- 


148 


THE  CANE-SUGAR  INDUSTRY. 


creased  yield  is  due  to  no  mean  extent  to  this  truly  economical  pro- 
ceeding. (3)  In  addition  to  the  two  causes  of  increase  already  noted 
and  which  are  not  sufficient  to  produce  the  large  rendement  obtained, 
must  be  mentioned  a  third,  the  action  of  the  excess  of  lime  and  its  pre- 
cipitation by  carbonic  acid  on  the  substances  in  the  juice  which  are 
truly  melassigenic.  Fully  half  of  the  total  increase  which  the  experi- 
ments have  demonstrated  is  due  to  this  cause.  It  is  true,  the  coefficient 
of  purity  of  the  juice  does  not  seem  to  be  much  affected  by  the  process, 
but  it  is  evidence  that  the  treatment  to  which  the  juice  is  subjected 
increases  in  a  marked  degree  the  ability  of  the  sugar  to  crystallize.  This 
fact  is  most  abundantly  illustrated  by  the  results  obtained.  Not  only 
this,  but  it  is  also  evident  that  the  proportion  of  first  sugars  to  all 
others  is  largely  increased  by  this  method.  This  is  a  fact  which  may 
prove  of  considerable  economic  importance." 

FIG.  40. 


It  only  remains  to  notice  in  connection  with  raw  sugars  two  forms 
of  apparatus  for  concentrating  raw-sugar  juice  which  have  had  con- 
siderable use  in  the  tropics.  The  first  of  these  is  the  "Wetzel  pan,"  an 
apparatus  shown  in  Fig.  40.  As  seen,  it  consists  of  a  pan  containing 
the  liquor,  in  which  dip  pipes  heated  by  steam  passing  through  them; 
while  the  cylinder,  formed  by  these  pipes,  is  caused  to  revolve  by  power 
applied  from  the  end  as  shown  in  the  cut.  The  large  heating  surface 
enables  steam  at  very  low  pressure  to  be  used,  exhaust  steam  from  the 
cane-mill  engine  being  sometimes  used  for  the  purpose.  Such  pans  are 
used  on  some  plantations,  in  the  absence  of  a  vacuum-pan,  to  finish  the 
concentration  begun  in  the  battery  or  copper-wall.  The  liquor  is 
brought  to  them  at  a  density  of  26°  to  27°  B.  The  other  form  of  appa- 
ratus referred  to  is  the  "Fryer  Concretor,"  in  which  no  attempt  is 
made  to  produce  a  crystalline  article,  but  only  to  evaporate  the  liquor 
to  such  a  point  that  when  cold  it  will  assume  a  solid  (concrete)  state. 
The  mass  is  removed  as  fast  as  formed,  and  being  plastic  while  warm 
it  can  be  cast  into  blocks  of  any  convenient  shape  and  size,  hardening 
as  it  cools.  In  this  state  it  can  be  shipped  in  bags  or  matting,  suffering 


PROCESSES  OF  TREATMENT.  149 

neither  deliquescence  nor  drainage.  The  "concretor  "  consists  of  a 
series  of  shallow  trays  placed  end  to  end  and  divided  transversely  by 
ribs  running  almost  from  side  to  side.  At  one  end  of  these  trays  is  a 
furnace,  the  flue  of  which  runs  beneath  them,  and  at  the  other  end  a 
boiler  and  an  air-heater,  which  utilize  the  waste  heat  from  the  flue, 
employing  it  both  to  generate  steam  and  to  heat  air  for  the  revolving 
cylinder.  The  clarified  juice  flows  first  upon  the  tray  nearest  the  fur- 
nace, and  then  flows  down  the  incline  towards  the  air-heater,  meander- 
ing from  side  to  side.  While  flowing  thus  it  is  kept  rapidly  boiling  by 
means  of  the  heat  from  the  furnace,  and  its  density  is  raised  from  about 
10°  B.  to  30°  B.  From  the  trays  it  goes  into  a  hollow  revolving  cyl- 
inder full  of  scroll-shaped  iron  plates,  over  both  sides  of  which  the 
thickened  syrup  flows  as  the  cylinder  revolves,  and  thus  exposes  a  very 
large  surface  to  the  action  of  hot  air  which  is  drawn  through  by  a  pan. 
In  this  cylinder  the  syrup  remains  for  about  twenty  minutes  and  then 
flows  from  it  at  a  temperature  of  about  91°  to  94°  C.,  and  of  such  con- 
sistency that  it  sets  quite  hard  on  cooling. 

Raw  sugars  are  often  gotten  now  of  sufficient  purity  to  allow  of  their 
immediate  use  without  further  treatment.  Such  is  not  the  usual  rule, 
however,  but  they  have  to  undergo  a  purifying  or  refining  in  order  to 
bring  them  to  the  requisite  purity  for  consumption.  The  sugar-refining 
process  is  simpler  in  its  theory  than  the  process  of  preparing  the  raw 
sugars,  but  requires  more  exactitude  in  its  execution,  and  more  elaborate 
and  costly  machinery  and  equipment.  The  problem  as  stated  is  a  much 
simpler  one  than  was  that  of  handling  the  raw  cane  juice;  it  is  now 
simply  a  redissolving  of  the  impure  crystalline  mass  of  raw  sugar,  free- 
ing the  solution  from  impurities,  and  then  crystallizing  afresh  the  pure 
sugar  from  it.  The  sugar  refinery  located  in  a  large  commercial  centre 
is  almost  always  a  building  of  considerable  height,  so  as  to  allow  of  the 
descent  by  gravity  of  the  sugar  solutions  from  floor  to  floor  as  the 
process  of  treatment  proceeds.  The  general  outline  of  the  treatment  will 
be  easily  followed  with  the  aid  of  the  diagram  in  Fig.  41.  The  raw 
sugars  as  they  arrive  are  discharged  from  hogsheads  or  bags  in  the  mixing 
room  on  the  ground  floor  through  wide  gratings  into  the  melting  tanks, 
or  "blow-ups,"  just  below,  where  boiling  water  and  steam  rapidly  dis- 
solve all  that  is  soluble  in  the  sugars.  These  tanks  hold  from  three 
thousand  to  four  thousand  five  hundred  gallons,  and  treat  from  nine  to 
thirteen  tons  of  sugar  at  a  time.  The  hogsheads  and  bags  are  similarly 
cleaned  out  by  live  steam.  The  crude-sugar  solution,  run  through  a 
coarse  wire  strainer  to  remove  mechanically-mixed  impurities,  is  then 
pumped  to  the  defecating  tanks  at  the  top  of  the  building.  The  defecat- 
ing is  not  done,  as  was  the  case  with  raw  juice,  with  lime,  but  with  some 
form  of  albumen,  as  bullock's  blood,  which,  coagulating  by  the  heat, 
encloses  and  carries  with  it  much  of  the  fine  suspended  impurities.  Fine 
bone-black  is  also  sometimes  added  along  with  the  blood.  The  contents 
of  these  defecating  tanks  are  boiled  up  and  agitated  thoroughly  for  from 
twenty  minutes  to  half  an  hour,  when  the  clear  liquor  is  run  off  in  the 
troughs  leading  to  the  bag-filters.  These  are  of  coarse,  thick  cotton 


150 


THE  CANE-SUGAR  INDUSTRY. 


FIG.  41. 


BONE  BLACK// 
FILTERS  // 


PROCESSES  OF  TREATMENT.  151 

twill,  four  or  five  feet  long,  and  but  a  few  inches  through.  These  filters 
collect  the  fine  suspended  slime  which  would  not  settle  in  the  defecating 
tanks.  It  has  been  found  impossible  to  replace  them  by  filter-presses  in 
the  working  of  the  raw  cane  sugars  at  present  in  the  market,  on  account 
of  the  slimy  character  of  the  separated  matter.  The  liquor,  now  con- 
taining soluble  impurities  only,  has  a  brown  color.  It  goes  from  the 
storage-tanks  below  the  bag-filters  to  the  bone-black-filters.  These  filters, 
immense  iron  tanks,  twenty  feet  high  and  eight  feet  in  diameter,  open 
through  man-holes  at  the  top  to  the  filter-room  floor.  They  have  false 
bottoms,  perforated,  over  which  a  blanket  is  fitted  to  prevent  the  bone- 
black  flowing  through  with  the  liquid.  The  largest  filters  hold  thirty 
to  forty  tons  of  the  bone-black.  When  they  are  filled  with  bone-black 
the  man-hole  is  closed,  and  the  syrup  from  the  cisterns  below  the  bag- 
filters  is  turned  on.  It  percolates  slowly  down,  is  allowed  some  time  to 
settle,  and  after  about  seven  hours  the  drawing  off  begins  through  a 
narrow  discharge-pipe.  The  filter  syrup  is  caught  in  different  tanks  as 
it  becomes  deeper  in  color,  and  the  colorless  syrup  first  obtained  used  for 
the  finest  sugars,  and  so  on.  When  the  charge  has  run  out,  the  sugar 
remaining  in  the  charcoal  is  washed  out  by  running  through  fresh  or 
"sweet  "  water,  and  the  bone-black  must  be  reburned  before  it  can 
again  be  used.  From  three-quarters  to  one  and  a  quarter  tons  of  black 
are  needed  per  ton  of  sugar  decolorized,  according  to  the  quality  of  the 
raw  sugars.  The  liquor  is  now  ready  to  be  concentrated  in  the  vacuum- 
pan  and  brought  to  the  crystallizing  point.  This  vacuum-pan  boiling 
has  already  been  described  under  raw  sugars.  The  processes  of  boiling 
are  somewhat  different  for  "mould  "  and  for  "soft  "  sugars.  The  best 
grades  of  syrup  boiled  to  an  even,  good-sized  grain  are  used  for  the 
former,  whether  loaf,  cut,  crushed,  or  pulverized.  As  the  ' '  masse-cuite  ' ' 
cools  it  is  run  into  conical  moulds  with  a  small  aperture  at  the  bottom, 
or  smaller  end,  through  which  the  uncrystallized  liquid  may  drain  off. 
After  this  has  been  allowed  to  drain,  water  or  white  syrup  is  poured  in 
at  the  top,  which  washes  the  crystals  as  it  slowly  filters  through.  After 
a  sufficient  time  allowed  for  drainage,  the  moulds  are  turned  over,  so 
that  the  small  quantity  of  syrup  in  the  point  of  the  cone  shall  distribute 
itself  through  the  mass.  The  result  is  the  hard  white  "sugar-loaf,"  or 
conical  form  of  sugar.  The  process  of  draining  in  moulds  is,  however, 
very  generally  replaced  by  the  use  of  large  centrifugals,  in  which  several 
cones  can  be  dried  at  a  time  in  a  few  minutes,  saving  enormously  in 
time  and  in  the  room  previously  occupied  by  the  large  amount  of  moulds 
needed  for  several  days'  working.  Such  a  hydro-extractor  for  cones  is 
shown  in  Fig.  42.  The  "soft  "  sugars,  the  crystallization  of  which  is 
completed  in  the  cooler  after  the  "masse-cuite  "  leaves  the  vacuum-pan, 
are  cured  mostly  by  centrifugals,  and  are  ready  for  barrelling  on  leaving 
them. 

2.  PRODUCTION  OF  SUGAR  FROM  THE  SUGAR-BEET. — In  considering  the 
question  of  the  production  of  sugar  from  the. sugar-beet,  two  things  must 
be  noticed:  first,  the  soft,  pulpy  character  of  the  beet,  which  allows 
of  much  more  complete  extraction  of  the  juice,  and,  second,  the  more 


152 


THE  CANE-SUGAR  INDUSTRY. 


complex  composition   of  the   juice,   which  necessitates  more   elaborate 
methods  of  purification  of  the  juice. 

The  cultivation  and  working  of  the  sugar-beet  has  been  developed  to 
so  much  greater  an  extent  in  Germany  than  any  other  country  that  we 
shall,  in  describing  the  extraction  of  sugar  from  the  beet,  notice  German 
methods  chiefly.  The  beets  are  first  washed,  brushed  and  deprived  of 
the  tops,  and  then  made  to  yield  their  juice  by  one  of  four  methods:  (1) 
by  pulping  them  and  pressing  the  pulp  either  in  hydraulic  presses  or 
between  rolls;  (2)  by  centrifugating  the  pulp;  (3)  by  the  maceration 

FIG.  42. 


process,  in  which  the  pulp  is  exhausted  with  either  warm  or  cold  water, 
and  the  residue  pressed ;  and  (4)  by  the  diffusion  process,  in  which  the 
beets  are  not  pulped  at  all,  but  are  cut  into  thin  transverse  sections, 
known  in  Germany  as  "schnitzel,"  in  France  as  "cosettes,"  and  in 
English  as  "chips."  These  are  then  put  into  a  series  of  vessels,  in  which 
a  current  of  warm  water  is  made  to  displace  the  sugar  juice  by  the 
principle  of  "osmosis,"  or  diffusion,  as  it  is  more  generally  called.  The 
first  three  processes  are  now  almost  entirely  displaced  in  Germany  by 
the  diffusion  process.  It  is  obvious  that  in  this  latter  the  juice  will  be 
freer  from  the  fine  mechanically  suspended  impurities  and  solid  particles 
than  in  the  processes  that  rupture  the  cell-walls.  In  this  country  the  beet- 


PROCESSES  OF  TREATMENT. 


153 


sugar  factories  have  all  been  equipped  with  diffusion  batteries  of  approved 
construction,  and  that  method  has  been  the  one  exclusively  employed. 
In  France  the  diffusion  method  has  not  become  so  generally  popular. 
As,  however,  it  yields  a  purer  juice  and  a  higher  percentage  of  the  same 
than  the  older  methods,  and  is,  as  just  stated,  the  one  that  is  displacing 
the  others,  we  shall  confine  ourselves  to  it. 

In  the  diffusion  method  of  Robert,  the  fresh  beets  are  cut  into  slices 
or  "chips  "  of  about  one  millimetre  thickness,  which  are  digested  with 
pure  water  at  from  50°  C.  to  60°  C.  This  allows  the  saccharine  beet 

FIG.  43. 


juice  to  pass  through  the  cell-walls  and  mix  with  the  water  and  the 
water  to  replace  it  in  the  cells,  while  the  colloid  non-sugar  remains  be- 
hind. The  vessels  used  for  this  diffusion  are  mostly  upright  iron  cylin- 
ders, as  shown  in  Fig.  43,  which  are  provided  with  a  man-hole  above  for 
charging  them  \vith  the  chips.  A  series  of  these  diffusors  connected 
together  is  known  as  a  battery.  They  are  brought  to  the  proper  tem- 
perature either  by  a  small  steam-coil  on  the  bottom  of  the  vessel  or  by 
so-called  "calorisators, "  or  juice-warmers,  detached  upright  heating 
vessels  inserted  between  every  two  diffusors.  A  diffusion -battery  of  ten 
cells,  with  juice-warmers,  is  shown  in  plan  in  Fig.  44.  From  the  bottom 
of  each  cell,  7  to  X,  goes  a  delivery-tube,  5,  to  the  bottom  of  the  juice- 


154 


THE  CANE-SUGAR  INDUSTRY. 


warmer,  where  it  divides  into  seven  tubes.    From  the  top  of  each  juice- 
warmer  a  tube,  a,  bent  at  right  angles,  connects  with  the  next  cell.   The 

FIG.  44. 


connection  of  the  opposite  cells,  V  and  VI,  as  well  as  the  cells  X  and  I 
at  the  other  end,  is  effected,  as  shown  in  the  ground-plan,  by  longer 


PROCESSES  OF  TREATMENT.  155 

tubes  making  these  bends  at  right  angles.  By  suitable  valves  in  the 
supply-  and  delivery-tubes  each  cell  can  be  shut  off  from  the  others. 
The  upper  man-holes  of  the  cells  are  all  reached  from  the  platform  e, 
which  runs  along  just  above  them;  the  valves  1,  2,  3  are  reached  from 
the  platform  f,  which  runs  along  lower  down,  supported  on  cross-pieces, 
as  shown  in  Fig.  45 ;  and  the  third  platform,  g,  gives  access  to  the  lower 
valves.  A  sunken  canal,  h,  in  this  lowest  platform  allows  of  the  ex- 
hausted chips  being  discharged  from  the  lower  man-holes  on  to  an  end- 
less band,  which  passes  around  two  wheels  and  delivers  them  into  as- 
cending buckets,  whence  they  go  to  the  chip-press,  which  dries  them. 
The  filling  of  the  cells  is  effected  by  means  of  a  swinging  trough,  not 
shown  in  the  cut,  connecting  with  a  chip-cutter  placed  on  a  higher  level. 

In  operating  the  battery,  water  at  66°  C.  is  run  into  the  first  cell, 
which  has  been  previously  filled  with  fresh  chips.  For  every  cubic  metre 
of  space  four  hundred  and  fifty  kilos,  of  chips  and  five  hundred  kilos, 
of  water  are  to  be  reckoned.  The  cell  remains  quiet  for  twenty  minutes, 
during  which  time  the  temperature  falls  to  45°  C.  The  connection  with 
the  neighboring  juice-warmer  is  now  opened,  and  the  thin  juice  made  to 
pass  into  this  by  forcing  fresh  cold  water  into  the  first  diffusion-cell. 
The  juice,  brought  in  the  warmer  to  66°  C.,  is  then  passed  into  the 
second  cell,  which  has  been  filled  with  chips.  After  twenty  minutes  the 
juice  in  No.  2  is  passed  into  the  adjoining  juice-warmer,  while  the  cell 
fills  up  with  the  juice  from  No.  1,  and  this  in  turn  with  fresh  water. 
No.  3,  which  had  been  filled  meantime  with  chips,  is  now  brought  into  the 
connection.  After  the  juice  has  been  kept  in  contact,  at  66°  C.,  with  the 
contents  of  each  of  the  three  cells  in  turn  for  twenty  minutes,  it  is  suf- 
ficiently concentrated  to  go  to  the  defecating  pan.  This  juice  is  therefore 
sent  to  be  purified,  while  No.  3  fills  up  with  the  thin  juice  from  No.  2. 
In  twenty  minutes  this  is. displaced,  and,  after  being  warmed  to  66°  C., 
goes  to  No.  4,  a  freshly-filled  cell.  After  suitable  action  here  it  goes 
direct  to  the  defecating  pan,  as  it  is  the  second  diffusate  of  three  cells 
and  the  first  of  a  fourth.  From  this  time  on,  as  a  new  cell  comes  into 
operation  the  juice  from  one  cell  goes  to  the  defecating  pan  until  the 
ninth  is  in  connection,  when  the  first  cell  is  disconnected  and  emptied  of 
the  exhausted  chips  and  then  filled  with  fresh.  While  this  is  going  on 
the  tenth  cell  has  been  connected;  and  then  the  second  is  to  be  emptied, 
while  the  first  cell  is  brought  into  connection  with  the  tenth.  Thus  nine 
cells  are  always  working  together  in  the  battery,  while  the  tenth  is  dis- 
connected for  emptying  and  filling. 

The  diffusion-cells  are  sometimes  arranged  in  a  semicircle  or  a  circle 
instead  of  a  straight  line,  as  this  arrangement  is  thought  to  be  more 
convenient  when  the  cells  are  to  be  filled  and  emptied.  Such  a  circular 
diffusion-battery  is  shown  in  Fig.  45,  and  the  method  of  filling  the  cells 
with  the  chips  or  slices  is  shown,  as  well  as  the  endless  belt  carrying  up 
the  buckets  of  exhausted  chips  to  be  emptied.  A  continuous  diffusor, 
consisting  of  one  long  cell,  in  which  the  chips  and  water  move  in  oppo- 
site directions,  so  that  as  the  juice  becomes  more  concentrated  it  shall 
meet  chips  richer  and  richer  in  sugar,  has  also  been  devised. 


156 


THE  CANE-SUGAR  INDUSTRY. 


FIG.  45. 


PROCESSES  OF  TREATMENT. 


157 


As  stated,  the  percentage  of  extraction  by  these  methods  is  higher 
and  the  juice  is  purer  than  by  any  other  method,  while  the  dried  chips 
also  serve  as  most  valuable  fertilizer  material  or  for  cattle  food.  Their 
average  composition  is:  ash,  5.67;  fat,  .49;  crude  fibre,  23.36;  crude 
protein,  8.70 ;  and  non-nitrogenous  extractives,  61.78.  A  modification  of 
this  diffusion  process  by  Bergreen,  already  found  advantageous  in  prac- 
tice, is  to  exhaust  the  cells  of  air  after  filling  them  with  fresh  beet-chips, 
and  then  to  allow  expanded  steam  to  enter,  so  as  to  coagulate  the  albu- 
minoids. The  usual  procedure  then  follows.  The  exhausted  chips  gotten 
thus  make  good  cattle  food,  as  they  are  richer  in  nitrogenous  matter. 

The  beet  juice,  by  whichever  of  the  four  methods  heretofore  men- 
tioned it  may  be  gotten,  is  now  to  be  purified.  The  general  outline  of 
the  method  of  working  up  the  juice  is  shown  on  the  accompanying 
diagram,  based  on  that  of  Post,*  but  modified  to  accord  with  recent  im- 
provements. Except  in  the  case  of  the  diffusion  juice  of  Bergreen 's 
process  mentioned  above,  the  crude  juice  is  heated  by  indirect  steam  to 
80°  C.  to  coagulate  the  albuminoids,  and  then  two  to  two  and  one-half 

FIG.  46. 


per  cent,  of  caustic  lime,  in  the  form  of  milk  of  lime,  is  added.  This 
lime  saturates  the  free  acids  and  throws  out  nitrogenous  compounds 
as  in  the  case  of  cane  juice,  and,  because  of  its  excess,  forms  soluble 
calcium  saccharates  with  some  of  the  sugar.  Carbonic  acid  gas  is  then 
added  until  the  precipitated  carbonate  of  lime  becomes  granular  and 
settles  readily.  At  this  time  there  still  remains  a  slight  excess  of  free 
lime, — about  .1  to  .2  per  cent.  The  contents  of  the  saturation-pan  are 
now  pumped  into  the  filter-presses  and  the  press-cakes  washed  free  from 
sugar  by  steam.  A  filter-press,  such  as  is  adapted  for  sugar-scums  and 
carbonatation  press-cakes,  is  shown  in  Fig.  46.  This  treatment  is  called 
the  first  carbonatation.  The  juice  may  be  filtered  now  at  once  through 
bone-black,  which  will  withdraw  the  remaining  lime  as  well  as  decol- 
orize it,  but  in  most  German  sugar-houses  it  is  subjected,  boiling  hot,  to 
a  second  treatment  with  one-half  per  cent,  of  lime,  and  then  completely 
neutralized  with  carbonic  acid.  This  is  called  the  second  carbonatation, 
or  the  saturation.  After  again  going  through  the  filter-press  the  juice 

*  Post,   Chemische   Technologic,   ii,   p.  274. 


158  THE  CANE-SUGAR  INDUSTRY. 

goes  to  the  bone-black-filters.  In  many  of  the  newer  German  sugar- 
houses  the  filtration  of  the  thin  juice  through  bone-black  is  no  longer 
practised,  as  repeated  saturations  with  lime  and  carbonic  acid  or  treat- 
ment with  sulphurous  acid  and  sulphites  have  so  clarified  it  as  to  make 
bone-black  unnecessary.  It  is  stated  that  at  Watsonville,  California,  in 
the  beet-sugar  factory  of  Spreckels,  bone-black  filtration  is  thus  dis- 
pensed with.  The  thin  filtered  juice  is  concentrated  in  double  or  triple 
effect  vacuum-pans  to  24°  or  25°  B.,  and  then  filtered  again  as  thick 
juice  through  bone-black.  This  second  filtration  takes  the  last  traces  of 
nitrogenous  materials  out,  and  the  remnant  of  lime  which  remained  in 
solution.  It  is  then  concentrated  in  the  vacuum-pan  to  crystallization. 

In  the  preparation  of  raw  sugar,  the  ' '  masse-cuite  "  is  dropped  from 
the  vacuum-pan  into  small  coolers  of  about  two  hundred  kilos,  capacity, 
in  which  it  becomes  cold  and  crystallization  is  completed.  The  contents 
of  these  coolers  are  then  mixed  and  broken  up  and  rubbed  to  a  paste 
with  the  aid  of  some  syrup,  and  the  whole  centrifguated.  The  sugar  so 
obtained  is  the  raw  beet-sugar  of  commerce.  The  syrup  obtained  is 
concentrated  in  a  vacuum-pan,  and  the  sugar  from  this  forms  the  second 
product,  which  sometimes  goes  into  commerce  and  sometimes  is  returned 
to  the  thick  juice  to  be  worked  up  with  it. 

As  was  stated  before,  raw  cane-sugar  can  be  obtained  by  care  and 
with  the  best  vacuum-pan  practice  so  nearly  pure  as  to  be  directly  avail- 
able for  use  without  any  special  refining.  In  the  case  of  raw  beet-sugar 
this  is  much  more  difficult  The  raw  beet-sugar,  though  it  may  be  well 
crystallized,  usually  contains  substances  of  decidedly  unpleasant  odor 
and  taste,  chiefly  decomposition  products  of  the  betaine  of  the  juice  (see 
composition  of  the  beet,  p.  136),  which  are  in  the  syrup  adhering  to  the 
crystals. 

As  end-products  from  100  kilos,  of  beets  containing  sixteen  per  cent, 
of  sucrose,  are  obtained : 

13.5  kilos  of  raw  beet  sugar  I.,  containing  96%  =  12.96  kilos  sucrose. 
1.0  kilo  of  secondary  product,  containing  92%  —  0.92  kilos  sucrose. 
2.2  kilos  of  molasses,  containing  50%  =  1.10  kilos  sucrose. 

14.98  kilos  sucrose. 

There  are  obtained,  in  addition,  six  kilos,  of  dry  beet  chips  and  ten 
kilos,  of  separated  scums. 

The  production  for  direct  consumption  of  a  commoner  sugar,  known 
in  Germany  as  "melis,"  or  lump-sugar,  is  an  important  branch  of  the 
raw  sugar-making.  In  this  case  the  contents  of  the  vacuum-pan  brought 
to  grain,  but  without  the  special  building  of  crystals,  are  discharged  into 
shallow  vessels  with  false  bottoms,  which  may  be  called  "warmers,"  in 
which  the  "masse-cuite  "  is  heated  up  from  60°  to  90°  C.,  which  has  the 
effect  of  redissolving  most  of  the  small  crystals.  The  warmed  syrup  is 
now  filled  into  the  moulds,  in  which  it  crystallizes  uniformly  to  a  compact 
whole.  This  grade  of  sugar  would  have  as  so  produced  a  light  yellow 
color,  which  is  usually  corrected  by  the  addition  of  ultramarine  blue. 

Of  course,  raw  beet-sugars  can  be  most  advantageously  purified  by  a 
complete  refining  process,  analogous  to  that  described  under  cane-sugar, 


PROCESSES  OF  TREATMENT. 


159 


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160  THE  CANE-SUGAR  INDUSTRY. 

in  which  they  are  redissolved,  clarified,  decolorized,  and  again  crystal- 
ized.  The  procedure  is  so  similar  to  that  described  under  the  refining 
of  cane-sugar  that  it  need  not  be  specially  noticed  here. 

3.  THE  WORKING  UP  OF  THE  MOLASSES. — It  is  stated  in  the  tabular 
view  of  the  working  of  cane-sugar  on  p.  140  that  the  molasses  is  used 
for  syrup  or  worked  over  into  molasses  sugars.  We  should  distinguish, 
however,  between  the  several  grades  of  molasses.  In  working  up  the  raw 
sugar  reference  was  made  to  first,  second,  and  third  sugars.  Correspond- 
ing to  each  of  these  three  grades,  of  course,  is  a  different  molasses,  some- 
times known  as  first,  second,  and  third  molasses,  and  sometimes  as  sec- 
ond, third,  and  fourth  molasses.  The  average  percentage  of  sucrose  and 
of  reducing  sugars  in  these  is  shown  from  the  analyses  of  the  United 
States  Department  of  Agriculture*  made  at  Magnolia,  Louisiana,  in  1884. 

First  molasses  ....Sucrose,  37.97  per  cent.  Reducing  sugar,  8.13  per  cent. 
Second  molasses  ..Sucrose,  41.23  per  cent.  Reducing  sugar,  18.32  per  cent. 
Third  molasses  ...Sucrose,  21.87  per  cent.  Reducing  sugar,  21.06  per  cent. 

The  percentage  of  solid,  non-sugar  in  the  first  and  second  of  these 
molasses  will  nearly,  if  not  quite,  equal  that  of  the  sucrose,  while  in  the 
third  it  considerably  exceeds  it. 

The  "first  molasses  "  is  sufficiently  pure  to  be  mixed  with  syrup 
sugar  in  the  pan  for  the  production  of  a  second  product  sugar ;  the 
"second  molasses  "  can  be  refined  as  such  for  brown  or  grocery  sugars, 
and  the  "third  molasses  "  is  so  sticky  and  impure  that  it  can  only  be 
sent  to  the  rum-distillery,  where  it  is  fermented  for  rum.  (See  p.  219.) 

With  respect  to  beet-root  molasses  the  case  is  different.  It  is  very 
impure  from  mineral  salts  and  nitrogenous  materials,  but  is  nearly  pure 
from  the  invert  or  reducing  sugar  so  abundant  in  cane-sugar  molasses, 
and  in  recent  years  it  has  been  found  possible  to  work  it  specifically 
for  the  extraction  of  the  sucrose,  of  which  over  ninety  per  cent,  is  now 
extracted,  thus  reducing  the  loss  of  sugar  to  a  minimum.  The  average 
composition  of  beet-sugar  molasses  is  given  at  fifty  per  cent,  of  sucrose, 
thirty  per  cent,  of  non-sugar,  and  twenty  per  cent,  of  water.  Of  these 
thirty  non-sugar,  ten  are  made  up  of  inorganic  salts,  chiefly  potash  com- 
pounds, and  twenty  of  organic  non-sugar  (see  composition  of  the  sugar- 
beet,  p.  136).  As  the  amount  of  beet-sugar  molasses  produced  in  Con- 
tinental Europe  annually  is  estimated  at  450,000  tons,  the  fifty  per  cent, 
of  sucrose  represents  25,000  tons  of  sugar  which  it  was  certainly  desir- 
able to  extract  if  possible.  The  processes  for  accomplishing  this  depend 
upon  either  one  or  the  other  of  two  principles :  either  to  withdraw  from 
the  molasses  the  potash  and  other  mineral  salts  which  prevent  the  crys- 
tallization of  the  sucrose,  or  to  precipitate  out  the  sucrose  in  combination 
with  calcium  or  strontium  as  an  insoluble  sucrate,  which  is  then  mixed 
with  water  and  decomposed  by  carbon  dioxide  or  used  in  the  defecation 
of  beet  juice  instead  of  lime.  ^ 

The  elimination  of  the  potash  salts  may  be  effected,  according  to 

*  Bulletin  No.  5,  p.  52. 


PROCESSES  OF  TREATMENT. 


161 


Newland's  proposal,  by  the  addition  of  aluminum  sulphate  so  as  to  form 
potash  alum,  which  is  crystallized  out,  or  by  the  "osmose  "  process,  in 
which  the  principle  of  diffusion  already  referred  to  (see  p.  152)  is  again 
made  use  of.  In  this  case  advantage  is  taken  of  the  fact  that  the  potash 
salts  are  the  most  crystalline  constituents  of  the  molasses,  and  hence  will 
pass  through  a  sheet  of  vegetable  parchment  more  rapidly  than  the  other 
constituents.  So  if  the  molasses  warmed  to  80°  or  90°  C.  be  made  to 
pass  in  a  stream  on  the  one  side  of  such  a  membrane  while  pure  water 
passes  on  the  other,  the  potash  salts  diffuse  through,  and  are  to  that 
degree  eliminated  from  the  molasses.  However,  the  difference  in  the 
rapidity  of  diffusion  of  the  salts  and  the  sucrose  is  not  sufficiently  great 

> 

FIQ.  47. 


to  allow  of  a  very  perfect  separation,  so  that  to  avoid  loss  of  sugar  the 
operation  must  be  stopped  before  the  elimination  of  salts  is  complete.  A 
little  more  than  half  of  the  sugar  can  be  recovered  from  the  molasses  in 
this  way.  The  apparatus  in  which  this  treatment  of  the  molasses  is 
carried  out  is  known  as  an  osmogene,  and  is  illustrated  in  Fig.  47.  It 
consists  of  a  number  of  very  narrow  but  high  and  deep  cells  adjoining 
each  other,  the  sides  ef  which  are  of  parchment  paper.  Through  alter- 
nate cells  in  this  system  goes  the  heated  molasses,  and  through  the  inter- 
vening cells  the  water  at  the  same  temperature,  each  connecting  with 
lateral  canals  for  the  supply  and  withdrawal  of  the  respective  liquids. 
The  ordinary  osmose  apparatus  of  the  German  sugar-houses  is  capable 
of  working  1000  kilos,  or  upwards  of  molasses  per  day,  and  at  a  cost  of 
1.60  marks  (38.4  cents)  per  100  kilos,  of  molasses.  The  osmose  sugar  is 
somewhat  darker  in  color  than  ordinary  second  or  third  sugar,  but  is 
of  pleasanter  and  sweeter  taste.  The  yield  of  the  osmose  process  varies 

11 


162  THE  CANE-SUGAR  INDUSTRY. 

with  the  grade  of  the  molasses  taken;  a  molasses  with  a  purity  coeffi- 
cient of  fifty-eight  to  sixty  will  yield  ten  to  twelve  per  cent,  of  the 
molasses  taken,  and  one  of  a  coefficient  of  sixty  to  sixty-five  will  yield 
seventeen,  or  sometimes  as  high'  as  twenty,  per  cent.  By  repeating  the 
osmose  process  thrice  the  yield  can  be  raised  to  thirty  per  cent,  out  of 
the  possible  fifty  per  cent,  of  sucrose  contained  in  the  molasses. 

Of  the  methods  depending  upon  the  formation  of  a  lime  or  strontia 
sucrate,  the  most  important  are  the  Scheibler-Seyferth  elution  process, 
the  Steffen  substitution  and  separation  processes,  and  the  strontium  proc- 
esses. 

In  the  first  of  these  processes,  finely  powdered  quicklime  is  added  to 
the  molasses,  which  has  been  previously  concentrated  in  vacuo  to  84°  to 
85°  Brix,  in  the  proportion  of  about  twenty-five  parts  of  the  former  to 
one  hundred  parts  of  the  latter.  The  lime  slakes  at  the  expense  of  the 
water  of  the  molasses,  and  leaves  the  tribasic  calcium  sucrate  in  the  form 
of  a  dry  porous  mass.  This  is  then  broken  up  and  put  into  the  ' '  elutors, ' ' 
vessels  which  are  somewhat  similar  in  design  to  the  cells  of  a  diffusion- 
battery.  The  impure  sucrate  is  here  systematically  washed  with  thirty- 
five  per  cent,  alcohol,  which  dissolves  away  from  it  most  of  the  adhering 
impurities.  The  washed  sucrate  is  then  brought  to  the  condition  of  a 
fine  paste  with  water,  and  either  decomposed  with  carbon  dioxide  or 
used  instead  of  lime  in  treating  fresh  beet  juice.  This  process  takes 
out  eighty-five  to  ninety  per  cent,  of  the  sugar  contained  in  the  molasses, 
but  the  cost  is  somewhat  greater  than  in  the  case  of  the  osmose  process. 
The  alcohol  is  recovered  from  the  washings  by  distillation.  Steffen 's 
substitution  process  depends  upon  the  difference  in  solubility  of  the  tri- 
calcium  sucrate  at  high  and  low  temperatures.  The  molasses  is  first 
diluted  so  that  it  shall  contain  about  eighty  per  cent,  of  sugar,  and  then 
caustic  lime  added  until  some  two  to  three  per  cent,  has  been  used.  The 
whole  mass  is  then  heated  to  115°  C.,  when  the  tricalcium  sucrate  is  pre- 
cipitated and  separated  by  the  use  of  a  filter-press.  The  sucrate  is  ground 
up,  again  filter-pressed,  and  then  can  be  used  in  defecating  sugar  juice. 
The  washings  from  the  filter-press  are  used  to  dilute  a  fresh  quantity  of 
molasses  to  the  degree  mentioned  before,  which,  treated  with  lime  in  the 
proper  proportion  and  heated  up,  separates  the  sucrate,  which  is  treated 
as  before.  After  about  the  twentieth  operation,  the  cooled  mother- 
liquors  and  wash-waters  are  treated  with  lime  alone,  and  the  residual 
liquors  after  this  treatment  are  then  rejected.  In  the  Steffen  separation 
process,  on  the  other  hand,  the  molasses  solution  is  kept  cold,  the  tem- 
perature not  being  allowed  to  rise  over  30°  C.  (86°  P.).  The  molasses 
is  diluted  until  the  density  shows  12°  Brix,  the  percentage  of  sugar  being 
then  from  seven  to  eight.  This  solution  is  cooled  down  to  15°  C.  (59° 
F.),  and  finely-powdered  quicklime  is  added  in  small  portions  at  inter- 
vals of  about  a  minute,  the  temperature  rising  a  little  each  time  and 
being  again  cooled  down.  The  mixing  of  the  molasses  and  the  lime,  in 
the  proportion  of  fifty  to  one  hundred  of  powdered  lime,  according  to 
quality,  to  one  hundred  of  dry  sugar,  in  the  solution  takes  place  in  a 
closed  mixing-vessel  of  iron  provided  with  tubes  through  which  cold 


PROCESSES  OF  TREATMENT. 


163 


water  is  kept  circulating,  and  with  a  mechanical  agitator  to  mix  the 
contents  uniformly.  The  insoluble  sucrate  separates  out  rapidly  in  the 
cold,  and  the  contents  of  the  mixer  A  (see  Fig.  48)  are  pumped  to  the 
filter-press  E,  where  the  sucrate  is  washed,  the  mother-liquor,  containing 
all  the  impurities  of  the  molasses,  being  put  aside  for  fertilizing  pur- 
poses, the  wash-water,  however,  being  collected  in  F  for  use  in  diluting 
new  quantities  of  molasses.  The  washed  sucrate  drops  from  the  filter- 
press  into  the  sucrate-mill  G,  where  it  is  mixed  to  a  thin  paste  with 
water,  and  then  pumped,  by  means  of  the  monte-jus  H,  to  the  receptacle 
J".  From  here  it  can  be  sent  into  the  first  saturation-vessel  K,  and  to 
the  filter-press  M,  and  to  the  second  saturation-vessel  8,  and  the  filter- 
press  0. 

The  process  which  at  the  present  time  is  most  favorably  regarded  and 
which  recovers  the  highest  percentage  of  sugar  is  the  strontium  process. 
In  this  the  sugar  is  precipitated  either  as  monostrontium  sucrate,  which 

FIG.  48. 


W/////ff/////////M^^^^ 

I 


is  quite  difficultly  soluble  in  the  cold,  or  as  bistrontium  sucrate  separating 
from  hot  solution.  According  to  Scheibler's  monosucrate  procedure,  the 
molasses  is  well  mixed  with  hot  saturated  strontium  hydroxide  solution, 
and  the  mixture  passed  over  cooling  apparatus  into  crystallizing  tanks, 
where  a  few  crystals  of  the  monosucrate  are  added  to  start  the  crystalli- 
zation. After  some  hours  the  whole  mass  is  changed  into  a  crystalline 
magma,  which  is  broken  up  and  put  through  a  filter-press.  The  white 
cakes  of  strontium  sucrate  go,  as  in  the  case  of  calcium  sucrate,  to  the 
treatment  of  crude  beet  juice,  while  the  mother-liquor  is  treated  with 
more  caustic  strontia  and  boiled,  when  bistrontium  sucrate  is  precipi- 
tated. This  is  dense  enough  to  be  washed  by  decantation,  and  then  can  be 
used  instead  of  strontia  solution  with  fresh  molasses  for  the  formation 
of  monostrontium  sucrate.  The  excess  of  strontia  is  recovered  from  all 
the  mother-liquors  and  worked  over  into  caustic  strontia.  By  the  other 
strontium  process  the  molasses  is  added  to  a  twenty-five  per  cent,  stron- 
tium hydroxide  solution,  both  taken  hot,  in  such  amount  that  for  one  part 


164  THE  CANE-SUGAR  INDUSTRY. 

of  sugar  about  two  and  one-half  parts  of  strontium  hydroxide  are  present. 
The  precipitated  bistrontium  sucrate  separates  rapidly,  and  the  mother- 
liquor  can  be  decanted  from  it.  The  sucrate  is  washed  with  hot  water  or 
with  a  ten  per  cent,  hot  strontium  solution.  In  order  to  decompose  the 
sucrate,  it  is  brought  in  a  refrigerating  chamber  and  cooled  to  10°  to 
12°  C.,  when,  after  twenty-four  to  seventy-two  hours'  standing,  accord- 
ing to  temperature,  etc.,  it  decomposes  into  crystallized  strontium  hy- 
droxide and  sugar  solution,  containing  something  less  than  half  of  the 
strontia.  After  filtering  off  the  crystallized  strontium  hydroxide,  the 
sugar-liquor  is  decomposed  with  carbon  dioxide  in  the  usual  way. 

In  Germany  in  1891-92,  48  sugar-houses  extracted  by  the  osmose 
process,  28  by  the  elution  and  precipitation  process,  3  substitution,  20 
separation,  and  1  strontium  process.  In  1906,  out  of  a  total  amount  of 
222,670  tons  of  molasses  worked  for  sugar  extraction,  210,560  tons  were 
worked  by  the  strontium  process  and  most  of  the  rest  by  the  lime  ' '  sepa- 
ration" process. 

4.  REVIVIFYING  OF  THE  BONE-BLACK. — The  bone-black,  or  "char," 
after  use  in  the  filters,  becomes  charged  with  impurities  and  loses  for 
the  time  its  decolorizing  power.  It  can,  however,  be  restored  to  activity, 
or  "revivified,"  by  suitable  treatment  so  as  to  be  used  again  for  filtra- 
tion, and  this  process  can  be  repeated  many  times  before,  by  the  gradual 
loss  of  its  porous  character  and  change  of  composition,  it  becomes  unfit 
for  use.  In  working  sugars  from  the  cane  this  revivification  is  a  much 
simpler  process  than  in  the  case  of  beet-sugars.  In  the  former  case, 
water  as  hot  as  possible  is  run  in  at  the  top  of  the  filter,  which  displaces 
the  sugar  solution  remaining  in  the  pores  of  the  char  and  forms  a  dilute 
solution  of  sugar  and  the  soluble  impurities  taken  up  from  the  liquor. 
This  dilute  solution  is  known  as  "  sweet- water, "  and  is  usually  boiled 
down  in  triple  effects  and  run  in  with  the  lower-grade  products.  After 
running  additional  hot  water  through,  the  filters  are  drained,  and  the 
moist  char,  after  a  partial  drying,  is  put  into  the  top  of  the  vertical 
retorts,  in  which  it  is  to  be  heated  out  of  access  of  air  for  the  decom- 
position of  the  organic  matter  still  remaining  in  the  pores  and  the  restor- 
ation of  its  absorbent  power.  Various  forms  of  char-kilns  are  in  use  in 
different  refineries.  That  shown  in  Fig.  49  represents  one  of  the  simpler 
forms  of  char-kilns.  The  moist  spent  black  from  the  filters  in  which  it 
was  washed  goes  on  to  the  floor  H,  where  it  is  dried  by  the  waste  heat 
passing  through  O  and  F,  and  then  goes  into  the  openings  at  J,  which 
are  kept  always  heaped  up.  The  black  descends  in  the  retort-pipes  A 
from  the  upper  cooler  portions  into  the  middle  hottest  part,  and  then, 
as  portions  are  withdrawn  below,  into  a  cooler  section  again.  The  black 
drawn  off  below  is  protected  from  the  air  by  being  received  into  closed 
receptacles  or  at  once  filled  into  the  bone-black-filters.  In  other  forms 
of  kilns,  the  retorts  are  rotated  slowly  by  mechanism  so  as  to  heat  all 
parts  equally. 

In  beet-sugar  refineries  the  revivifying  of  the  "char,  as  before  stated, 
is  a  more  tedious  process.  This  is  in  part  because  the  juices  and  syrups 
have  been  limed  in  such  excess  in  the  preliminary  stages  of  treatment, 


PROCESSES  OF  TREATMENT. 


165 


and  in  part  because  the  beet  juice  contains  much  more  albuminoid  and 
organic  non-sugar,  which  is  absorbed  in  the  pores  of  the  char  and  can- 
not be  gotten  rid  of  by  simple  washing.  The  first  step  in  the  revivifying, 
then,  in  this  case,  is  a  treatment  with  a  calculated  amount  of  hydro- 
chloric acid  to  remove  the  excess  of  carbonate  of  lime ;  after  this  a  thor- 


FIG.  49. 


ough  washing  of  the  black  in  special  washing-machines,  such  as  the  Kluse- 
mann  washer,  shown  in  Fig.  50;  then  a  fermentation  to  decompose  into 
simpler  and  soluble  constituents  the  absorbed  albuminoids  and  other 
organic  matter.  The  fermentation  may  be  either  what  is  termed  the 
dry  fermentation,  in  the  presence  of  a  very  small  quantity  of  water,  or 
the  moist  fermentation  in  the  presence  of  a  larger  amount.  The  first 
takes  from  twelve  to  twenty  hours,  while  the  latter  requires  from  six  to 
seven  hours  only.  The  black,  after  the  fermentation,  is  treated  with 


166 


THE  CANE-SUGAR  INDUSTRY. 


PRODUCTS  OF  MANUFACTURE.  167 

boiling  alkaline  solutions,  washed,  and  then  burned  in  char-kilns  as 
already  described.  The  char  seems  to  improve  in  filtering  power  at  first, 
as  a  consequence  of  revivifying,  but  soon  loses  again  and  runs  down 
steadily  in  value.  This  is  in  large  part  due  to  the  separation  out  in  the 
pores  of  carbonized  residue  from  the  burning.  This  carbon  has  no  de- 
colorizing power  like  the  nitrogenized  carbon  of  the  original  bone-black, 
but  simply  clogs  the  pores  of  the  char  and  mechanically  obstructs  its 
action. 

A  new  process  of  Soxhlet  whereby  a  mixture  of  fine  ground  wood  fibre 
and  infusorial  earth  is  added  to  the  solutions  before  filter-pressing  has 
produced  such  clear  filtrates  that  the  use  of  bone-black  is  largely  dis- 
pensed with  even  in  refining  the  raw  beet-sugar. 

HE.  Products  of  Manufacture. 

1.  RAW  SUGARS. — The  composition  of  the  juice  from  both  the  sugar- 
cane and  the  sugar-beet  has  been  stated,  and  the  processes  for  preparing 
the  raw  sugar  from  each  of  these  sources.  We  may  now  examine  more 
closely  the  character  of  the  products  obtained.  The  raw  cane-sugar, 
made  as  it  is  chiefly  in  the  tropics  under  a  variety  of  conditions  of  work- 
ing, from  the  most  primitive  to  the  most  highly  improved,  has  come  into 
commerce  under  a  great  variety  of  names  as  well  as  of  varying  grades  of 
purity.  The  raw  beet-sugar  is  usually  known  as  first,  second,  or  third 
product  sugar.  (See  p.  158.) 

Muscovado  is  a  brown  sugar  produced  in  the  West  Indies,  generally 
by  open-pan  boiling,  which  has  been  drained  in  hogsheads  or  perforated 
casks,  and  so  freed  in  large  part  from  the  accompanying  molasses. 

Concrete,  or  concreted  sugar,  is  the  product  of  the  Fryer  concretor 
(see  p.  148)  or  similar  form  of  apparatus,  and  is  a  compact,  boiled-down 
mass,  containing  both  the  crystallizable  sugar  and  impurities  which  ordi- 
narily go  into  the  molasses.  It  shows  little  or  no  distinct  grain. 

Clayed  sugars  have  been  freed  from  the  dark  molasses  by  covering 
them  in  moulds  by  moist  clay,  which  allows  of  a  gradual  washing  and 
displacement  of  the  adhering  syrup. 

Bastards  is  the  name  given  to  an  impure  sugar  gotten  by  concen- 
trating molasses  and  allowing  to  crystallize  slowly  in  moulds. 

Jaggery  is  the  name  given  to  a  very  impure  East  Indian  palm-sugar, 
sometimes  refined  in  England,  but  chiefly  consumed  in  the  country  of  its 
production. 

Demerara  crystals  are  the  product  of  the  best  vacuum-pan  boiling 
and  have  been  well  purged  in  the  centrifugals.  They  have  the  light 
yellow  bloom  due  to  treatment  with  sulphuric  acid.  (See  p.  146.) 

These  Demerara  crystals  have  also  been  brought  to  the  United  States 
with  very  dark  brown  color.  This,  however,  was  only  superficial,  and 
was  capable  of  removal  by  centrifugating  with  a  lighter-colored  syrup. 
The  dark  color  was  imparted  like  the  yellow  bloom  by  the  action  of  sul- 
phuric acid  added  in  the  vacuum-pan  before  discharging  the  contents  of 
the  same. 


168 


THE  CANE-SUGAR  INDUSTRY. 


The  composition  of  a  variety  of  raw  cane-  and  beet-sugars  is  given  in 
the  accompanying  table : 


DESCRIPTION  OF  SUGAR. 

Sucrose. 

Glucose. 

Organic 
non- 
sugar. 

Ash. 

Water. 

Authority. 

Cane,  Cuba  (centrif.)  .  .  . 

91.90 

2.98 

2.70 

0.72 

1.70 

Wigner  and  Harland. 

Cuba  (muscovado)  . 

92.35 

3.38 

0.66 

0.77 

2.84 

Wallace. 

9040 

3.47 

1.55 

0.36 

4.22 

Wigner  and  Harland. 

Trinidad  

88.00 

5.14 

1.67 

0.96 

4.23 

Wigner  and  Harland. 

Porto  Rico  

87.50 

4.84 

2.60 

0.81 

4.25 

Wigner  and  Harland. 

St.  Vincent  

92.50 

3.61 

2.45 

0.63 

0.81 

Wigner  and  Harland. 

9080 

4.11 

0.77 

1.12 

3.20 

Wallace. 

94.50 

2.63 

0.39 

1.50 

0.98 

Wigner  and  Harland. 

Unclayed  Manila  .  . 

82.00 

6.79 

3.24 

2.00 

5.97 

Wigner  and  Harland. 

Concrete  

84.20 

8.45 

1.70 

1.10 

4.55 

Wallace. 

Melada  

67.00 

11.36 

1.93 

0.91 

18.80 

Wallace. 

Bastards       

68.30 

15.00 

1.20 

1.50 

14.00 

Wallace. 

Palm  East  Indian  

86.00 

2.19 

2.89 

2.88 

6.04 

Wiener  and  Harland. 

Beet,  First  product  .... 

94.17 

2.14 

1.48 

2.21 

Bodenbender. 

"      Second  product  .  .  . 

91.68 

2.49 

2.92 

2.91 

Bodenbender. 

2.  REFINED  SUGARS. — The  commercial  designations  of  refined  sugar 
are  very  varied.     We  may  distinguish  in  general  between  hard  sugars 
and  soft  sugars,  the  former  of  which  are  more  thoroughly  and  carefully 
dried  by  the  aid  of  artificial  heat,  while  the  latter  are  merely  centrifu- 
gated,  and  so  retain  from  three  to  four  per  cent,  of  water  in  the  traces 
of  syrup  adhering  to  the  sugar.    To  the  former  class  belongs  sugar  ' '  crys- 
tals," or  sugar  in  well-formed  individual  transparent  crystals,  which 
are  as  pure  as  rock-candy,  as  well  as  loaf-sugar  in  the  forms  of  pulver- 
ized, crushed,  granulated,  and  cube  sugars.     To  the  latter  belong  what 
are  called  grocery  sugars,  of  which  the  finest  grades  are  called  A  sugars, 
the  next  B  sugars,  and  so  on. 

In  Germany  the  finest  white  beet-sugars  are  known  as  "raffinade," 
inferior  grades  as  "melis  "  (or  Brodzucker),  as  "pile,"  and  as  "farm," 
the  last  of  which  is  of  inferior  grain  and  color. 

The  hard  sugars  in  general  all  show  a  sucrose  percentage  of  ninety- 
nine  or  over,  while  the  soft  cane-sugars  and  the  second  grade  beet-sugars 
show  from  ninety-six  to  ninety-eight  per  cent. 

3.  MOLASSES  AND  CANE-SUGAR  SYRUPS. — The  molasses  may  be  termed 
the  mother-liquor  of  the  crystallized  product,  the  sugar.     It  is  never 
found  possible  in  practice,  however,  to  crystallize  all  the  sugar  out  or 
to  get  a  molasses  which  shall  not  contain  sucrose.    The  potash  salts,  and 
in  a  lesser  degree  the  calcium  salts,  which  are  present  in  the  crude  juice 
are  "melassigenic," — that  is,  prevent  the  crystallization  of  a  certain 
amount  of  the  sucrose ;  the  invert  sugar,  or  glucose,  operates  in  the  same 
way,  and  the  long-continued  heating  of  the  sugar  solutions  also  has  the 
effect  of  increasing  the  molasses.     In  France,  for  instance,  the  rende- 
ment,  or  amount  of  crystallized  sugar  obtainable  in  refining  of  raw 
sugars,  is  calculated  by  deducting  from  the  total  sucrose  twice  the  glu- 
cose, and  from  three  to  five  times  the  ash.    In  the'  case  of  cane-sugars  the 
ash  is  not  so  melassigenic,  not  being  so  largely  composed  of  potassium 
compounds  as  with  the  beet,  and  a  deduction  of  one  and  a  half  times 
the  glucose  is  considered  sufficient  to  allow  for  the  impurity. 


PRODUCTS  OF  MANUFACTURE. 


169 


The  experience  during  some  years  with  sorghum-sugar,  as  manu- 
factured by  the  United  States  Bureau  of  Agriculture  and  several 
sorghum-sugar  factories  in  Kansas,  has  shown  that  this  rule  does  not 
apply  to  sorghum.  Professor  Swenson,  the  chemist  of  the  Parkinson 
Company  at  Fort  Scott,  Kansas,  found  that  in  the  case  of  sorghum  juice 
the  glucose  and  other  solids,  known  as  "non-sugar,"  prevent  only  two- 
fifths  of  their  weight  of  cane-sugar  from  crystallizing,  so  that  in  the 
season  of  1887,  instead  of  there  being  only  61.6  pounds  available  sugar 
per  ton  of  cane  worked  as  the  analyses  indicated  according  to  the  old 
rule,  as  a  matter  of  fact,  130.5  pounds  were  obtained. 

But  with  the  sugar-cane  and  the  sugar-beet  the  percentage  of  sucrose, 
in  both  the  raw  molasses  produced  in  the  extraction  of  the  sugar  from 
the  juice  and  "refined  molasses,"  the  syrup  produced  in  the  process  of 
refining,  is  quite  large.  The  composition  of  the  first,  second,  and  third 
molasses  of  the  Louisiana  cane-sugar  plantation  has  already  been  given 
(see  p.  160),  as  well  as  the  average  composition  of  beet-root  molasses. 
The  following  analysis  of  a  variety  of  molasses  will  further  illustrate 
the  differences  in  the  several  grades: 


Sucrose. 

Glucose. 

Ash. 

Organic 
non- 
sugar. 

Water. 

Authority. 

From  sugar-cane  : 
Green  syrup    

62.7 

80 

1.0 

0.6 

27.7 

Wallace. 

Golden  syrup  

39.6 

33.0 

2.5 

2.8 

22.7 

Wallace. 

Treacle  

32.5 

37.2 

35 

3.5 

23.4 

Wallace. 

West  Indian  molasses    . 
Dark  molasses   

47.0 
35.0 

20.4 
10.0 

2.6 
5.0 

2.7 
10.0 

27.3 
20.0 

Wallace. 
J.  H.  Tucker. 

From  beets  : 
Beet-sugar  molasses    .  . 
Beet-sugar  molasses    .  . 
Beet-sugar  molasses    .  . 

46.7 
50.0 
55.0 

0.6 
Trace. 

13.2 
10.0 
12.0 

15.8 
20.0 
13.0 

23.7 
20.0 
20.0 

Wallace. 
Wigner  and  Harland. 
J.  H.  Tucker. 

It  will  be  seen  from  these  analyses  that  the  percentage  of  sucrose  is 
usually  much  higher  in  the  beet-root  molasses,  which  is  explained  by  the 
large  percentage  of  ash  and  organic  non-sugar.  On  the  other  hand,  the 
glucose,  or  invert  sugar,  is  large  in  the  cane-sugar  molasses,  but  almost 
entirely  wanting  in  the  beet-sugar  molasses.  The  latter,  however,  always 
contains  raffinose,  another  variety  of  sugar  always  present  in  the  beet 
juice,  betaine,  a  nitrogenous  base,  and  proteids.  The  proportion  of  salts 
contained  in  beet-root  molasses  is  usually  ten  to  fourteen  per  cent., 
whereas  refiner's  molasses  from  cane-sugar  rarely  contains  half  that 
proportion. 

The  term  green  syrup,  used  above,  is  given  to  the  syrup  centrifugated 
from  the  second  products  in  the  refining  process. 

Golden  syrup  is  produced  from  a  refiner's  molasses  by  diluting,  filter- 
ing through  bone-black,  and  then  concentrating. 

Treacle  is  the  name  formerly  given  to  the  drainings  from  the  dark 
molasses  sugars  called  bastards.  (See  p.  167.) 

Cane-sugar  molasses,  when  refined  and  brought  to  the  condition  of 
light-colored  syrups,  forms  a  common  article  of  domestic  consumption 


170  THE  CANE-SUGAR  INDUSTRY. 

under  the  general  name  of  table  syrup.  The  table  syrups  of  the  present 
day,  however,  cannot,  as  a  rule,  claim  to  be  simple  products  of  the  refin- 
ing process,  as  they  are  almost  always  largely  admixed  with  the  cheaper 
glucose  syrup,  and  the  cane-sugar  product  in  them  is  often  entirely 
replaced  by  this  latter.  A  glucose  product,  known  as  "mixing  syrup," 
is  quite  openly  sold  for  this  purpose. 

Beet-sugar  molasses  is  not  adapted  for  use  as  table  syrup  on  account 
of  the  unpleasant  taste  and  odor,  due  to  the  nitrogenous  principles 
present.  It  is,  as  before  described,  worked  for  the  extraction  of  the 
sugar,  or  it  is  fermented  for  alcohol. 

4.  MISCELLANEOUS  SIDE-PRODUCTS. —  (1)  Exhausted  Residue  from  the 
Sugar-cane  or  Sugar-beet. — The  character  of  this  residue  differs  very 
greatly  according  to  the  method  of  juice  extraction  which  has  been  fol- 
lowed. The  common  sugar-cane  residue  from  the  roll-mills,  known  as 
"bagasse,"  consists  of  the  fibre  and  cellular  material  of  the  cane  still 
enclosing  some  six  per  cent,  of  sucrose,  or  about  one-third  of  the  total 
eighteen  per  cent,  which  the  fresh-cut  cane  contains.  It  is  very  largely 
used  as  fuel  on  the  sugar  plantations,  and  the  ash  serves  to  some  extent 
as  fertilizing  material  for  the  soil.  The  cane-fibre,  when  freed  more 
fully  from  the  sugar  by  the  diffusion  process,  has  been  proposed  as  a 
source  of  paper-stock.  (See  p.  140.) 

Both  the  pressed  pulp  and  the  exhausted  diffusion-chips  from  the 
sugar-beet  are  recognized  as  valuable  cattle  food.  Marcker  found  in  the 
dried  press-cake  1.227  per  cent,  of  nitrogen.  The  exhausted  chips  of  the 
diffusion-cells  are  still  richer  in  nitrogen,  as  the  diffusion  process  does 
not  extract  as  much  nitrogenous  matter  as  the  method  of  crushing. 

(2) Scums  and  Saturation  Press-cakes. — In  describing  the  production 
of  raw  cane-sugar  mention  was  made  of  the  scums,  which  had  at  one 
time  been  thrown  away,  but  which  when  filter-pressed  yielded  a  very 
considerable  additional  amount  of  sugar.  The  press-cake  obtained  in 
this  treatment  has  also  a  value.  It  contains  on  an  average  as  taken  from 
the  press  45.17  per  cent,  of  water,  15.67  per  cent,  of  ash,  3.49  per  cent, 
of  phosphoric  anhydride,  and  1.14  per  cent,  of  nitrogen,  or,  reckoned 
on  the  dry  material,  28.56  per  cent,  of  ash,  6.33  per  cent,  of  phosphoric 
anhydride,  and  2.10  per  cent,  of  nitrogen.  Its  value,  as  taken  from 
the  press,  at  the  ruling  rates  for  fertilizing  materials,  would  be  $10.64 
per  ton.*  Where  the  carbonatation  process  is  used,  and  the  excess  of 
lime  removed  by  carbon  dioxide,  the  scums  and  carbonate  of  lime  are 
found  together  in  the  press-cake  gotten  by  filtering.  In  the  experimental 
tests  of  the  carbonatation  process  as  applied  to  cane-sugar  made  by  the 
United  States  Department  of  Agriculture  at  Fort  Scott,  Kansas,  in 
1886, f  the  press-cake  obtained  after  saturation  and  filtering  when  dried 
was  found  to  contain  9.585  per  cent,  of  albuminoids  and  17.45  per  cent, 
of  other  organic  matter.  The  saturation  press-cake  of  the  beet-sugar 
process  does  not  contain  so  high  a  percentage  of  albuminoids,  but  a  much 

*  Bulletin  of  Department  of  Agriculture,  No.   11,  p.   16. 
t  Ibid.,  No.  14,  p.  54. 


PRODUCTS  OF  MANUFACTURE.  171 

larger  amount  of  nitrogenous  compounds  remains  in  the  clarified  juice, 
giving  rise  to  the  escape  of  ammonia  on  concentration  in  the  vacuum-pan 
and  showing  itself  in  the  molasses. 

(3)  Exhausted  Bone-Hack. — The  bone-black  after  repeated  revivify- 
ing  (see  p.  164)   becomes  at  last  valueless  for  filtration  purposes  and 
passes  out  of  the  sugar-refinery,  going  to  the  manufacturer  of  fertilizers, 
for  whom  it  is  a  very  valuable  material.     The  more  calcium  phosphate 
and  the  less  calcium  carbonate  it  contains,  the  more  valuable  it  is  for 
superphosphate  manufacture,  as,  on  the  addition  of  sulphuric  acid,  the 
liberated  phosphoric  acid  remains,  adding  to  the  value  of  the  product, 
while  the  carbonic  acid  is  driven  off.    The  exhausted  bone-black  contains 
on  an  average  thirteen  per  cent,  of  calcium  carbonate,  sixty  to  seventy- 
four  per  cent,  of  calcium  phosphate,  four  per  cent,  of  carbon,  and  four- 
tenths  to  six-tenths  per  cent,  of  nitrogen. 

(4)  Vinasse,  or  Molasses  Residues. — When  the  beet  molasses  is  fer- 
mented for  the  production  of  alcohol,  the  residual  liquor,  which  contains 
all  the  potash  salts  of  the  molasses,  is  known  in  French  as  ' '  vinasse, ' '  or 
in  German  as  "schlempe."    It  is  of  about  41°  B.  and  acid  in  reaction. 
It  is  neutralized  with  calcium  carbonate  and  then  evaporated  down  to 
dryness  and  calcined.     The  black  porous  residue  so  obtained  contains 
thirty  to  thirty-five  per  cent,  of  potassium  carbonate,  eighteen  to  twenty 
per  cent,  of  sodium  carbonate,  eighteen  to  twenty-two  per  cent,  of  potas- 
sium chloride,  six  to  eight  per  cent,  of  potassium  sulphate,  and  fifteen 
to  twenty-eight  per  cent,  of  insoluble  matter.     It  is  exhausted  with  hot 
water,  and  the  extract  evaporated  down,  when  potassium  sulphate  and 
afterwards  sodium  carbonate  separate  out.     On  cooling,  potassium  chlo- 
ride and  potassium  sulphate  crystallize  out,  and  the  mother-liquor  con- 
tains potassium  carbonate  admixed  with  some  sodium  carbonate.     It  is 
possible  by  this  gradual  evaporation  and  fractional  crystallization  to 
bring  the  crude  potashes  to  a  purity  of  ninety  per  cent.    In  this  produc- 
tion of  the  solid  potashes  from  the  molasses  residue  all  the  nitrogen  of 
the  molasses  is  lost.    To  prevent  this,  C.  Vincent,  a  French  chemist,  has 
proposed  to  submit  the  evaporated  vinasse  to  a  dry  distillation  instead 
of  calcination  in  the  air.     The  residue  of  this  distillation  is  an  open  and 
very  porous  coke  containing  all  the  mineral  salts  of  the  molasses,  which 
can  then  be  extracted  as  before.     The  products  of  distillation  are  an 
illuminating  and  heating  gas,  ammonia  water,  and  a  small  amount  of 
tar.     The  ammonia  water  is  the  most  interesting  product.     It  contains 
besides  carbonate,  sulphide  and  cyanide  of  ammonium,  methyl  alcohol, 
and  notable  quantities  of  trimethylamine.    This  latter  can  be  decomposed 
at   320°   C.   by  dry  hydrochloric   acid   gas  into  methyl   chloride   and 
ammonia,  and  on  passing  the  products  through  aqueous  hydrochloric  acid, 
the  methyl  chloride  goes  through  unabsorbed,   while  the   ammonia  is 
taken  up.     The  methyl  chloride  is  of  great  value  for  ice  machines  and 
for  the  manufacture  of  methylated  aniline  colors.     (See  p.  457.)     The 
process  was  quite  largely  introduced,  but  as  in  recent  years  the  molasses 
is  worked  over  for  sugar  in  increasing  amounts,  less  molasses  is  fer- 
mented, and  hence  less  vinasse  is  obtained. 


172 


THE  CANE-SUGAR  INDUSTRY. 


IV.  Analytical  Tests  and  Methods. 


1.  DETERMINATION  OF  SUCROSE.  —  (A)  Optical  Methods.  —  Among  the 
most  important  physical  properties  of  many  of  the  varieities  of  sugars  is 
the  power  possessed  by  their  solutions  of  rotating  the  plane  of  polariza- 
tion to  the  right  or  the  left.  The}'  are  accordingly  classified  as  dextro- 
rotatory, Igevo-rotatory,  or  optically  inactive  in  case  no  power  of  circular 
polarization  is  manifested.  This  property  as  possessed  by  solutions  of 
cane-sugar,  of  deviating  the  polarized  ray  in  a  fixed  and  definite  degree, 
has  been  made  the  basis  of  the  method  of  analysis  by  means  of  polari- 
scopes.  The  fundamental  idea  involved  in  these  instruments  is  to  com- 
pensate for  and  so  determine  the  optical  rotatory  power  of  sugar  solu- 

FIG.  51, 


tions  of  unknown  strength  by  the  corresponding  circular  polarizing 
action  of  quartz  plates  of  known  thickness,  and  hence  of  known  power. 
The  earliest  of  polariscopes  was  the  Mitscherlich  instrument,  but  those 
now  in  use  for  sugar  analysis  are  either  the  Soleil-Ventzke-Scheibler,  the 
Soleil-Dubosq,  the  Laurent  shadow  instrument,  or  the  Schmidt  and 
Haensch,  which  last  claims  to  combine  the  best  features  of  the  Soleil  and 
the  Laurent  instruments.  A  general  view  and  a  longitudinal  section  of 
this  instrument  is  given  in  Fig.  51.  The  glass  tube  containing  the  sugar 
solution  is  shown  lying  in  the  axis  of  the  telescope  and  the  polarizing 
prisms.  To  the  right  below  is  shown  the  polarizing  prism  (the  so-called 
Jellet-Cornu  prism),  to  the  left  is  the  analyzing  prism,  a  quartz  plate, 
quartz  wedges  of  opposite  rotatory  power,  and  the  lenses  of  the  telescope, 
with  a  plate  of  bichromate  of  potash  to  correct  for  any  color  in  the  field. 


ANALYTICAL  TESTS  AND  METHODS.  173 

In  this  instrument,  which  uses  white  light,  the  field  of  view  is  a  circle, 
which,  with  the  instrument  at  0°  and  nothing  intercepting  the  light,  is 
of  a  uniform  gray  tint.  When  a  sugar  solution  is  interposed,  one-half 
of  the  circle  becomes  darker  than  the  other,  and  the  quartz  wedges,  con- 
trolled by  the  screw  shown  underneath,  must  be  moved  to  compensate  for 
the  rotation  due  to  the  sugar  solution  and  to  restore  the  uniformity  of 
tint.  The  instrument  is  so  graduated  that  one  degree  of  displacement 
on  the  scale  corresponds  to  .26048  gramme  of  cane-sugar  dissolved  in  100 
cubic  centimetres  of  water  and  viewed  through  a  200-millimetre  tube. 
Therefore  26.048  grammes  of  the  sugar  to  be  analyzed  are  weighed  out. 
If  chemically  pure  and  anhydrous,  the  solution  of  the  strength  stated 
should  read  one  hundred  degrees  of  displacement,  or  one  hundred  per 
cent,  of  sugar,  and  if  impure,  correspondingly  less. 

In  the  application  of  polariscope  analysis  to  cane-sugars  two  cases 
may  arise:  first,  when  no  other  optically  active  substance  is  present, 
and,  second,  when  glucose  or  invert  sugar  is  also  present. 

(a)  Absence  of  other  Optically  Active  Substances. — The  weighed 
sample  is  dissolved  in  about  fifty  cubic  centimetres  of  water  in  a  flask 
marked  for  one  hundred  cubic  centimetres.  As  soon  as  the  sugar  is  all 
dissolved,  a  few  cubic  centimetres  of  a  solution  of  basic  acetate  of  lead 
are  added,  and  two  or  three  cubic  centimetres  of  cream  of  hydrated 
alumina.  The  liquid  is  well  agitated,  and  then  the  flask  is  filled  nearly 
to  the  mark  on  the  neck  with  water  and  the  froth  allowed  to  rise  to  the 
surface,  when  it  is  flattened  by  the  addition  of  a  drop  of  ether.  Water 
is  now  added  exactly  to  the  mark,  the  contents  of  the  flask  thoroughly 
agitated,  and  the  liquid  filtered  through  a  dry  filter.  In  the  case  of  very 
dark  sugars,  purified  and  perfectly  dry  bone-black  has  been  added  for 
clarifying  purposes.  However,  it  is  generally  acknowledged  to  intro- 
duce error  by  its  absorption  of  small  amounts  of  sugar,  so  that  it  is 
now  dispensed  with,  or  if  used  on  the  dry  filter,  the  first  third  of  the 
filtrate  is  rejected  and  the  later  portions  only  used.  Allen*  recommends 
instead  the  use  of  a  ten  per  cent,  solution  of  sodium  sulphite.  The  tube 
of  the  polariscope  is  now  rinsed  with  the  clear  sugar  solution  and  then 
filled  with  the  same,  the  open  end  closed  with  a  smooth  glass  plate  held 
in  place  by  a  brass  cap,  which  is  screwed  on.  The  tube  containing  the 
sugar  solution  is  then  placed  in  the  instrument,  and  the  lower  thumb- 
screw turned  until  the  uniformity  of  shade  in  the  two  halves  of  the  field 
is  restored,  when  the  number  of  degrees  (or  percentage  of  cane-sugar 
in  the  sample)  is  read  off  on  the  scale. 

(6)  Presence  of  Glucose,  Invert  Sugar,  or  other  Optically  Active 
Substance. — The  action  of  acids  upon  cane-sugar  has  already  been  stated 
to  cause  inversion, — i.e.,  change  of  the  sucrose  into  dextrose  and  levu- 
lose.  Both  these  varieties  of  sugars  differ  from  sucrose  in  their  optical 
power.  If,  then,  these  alteration  products  accompany  the  sucrose  in  a 
cane-sugar  sample,  the  results  of  the  polariscope  reading  may  be  viti- 
ated. Some  writers  have  held  that  the  invert  sugar  present  in  raw 

*  Commercial  Organic  Analysis,  3d  ed.,  vol.  i.  p.  257. 


174  THE  CANE-SUGAR  INDUSTRY. 

cane-sugars  and  syrups  is  optically  inactive,  but  the  statement  seems 
to  have  been  disproved  by  Meissl.  Besides,  in  raw  beet-sugars  and 
syrups,  raffinose,  a  very  strong  dextro-rotatory  sugar,  is  found  vitiating 
the  readings  for  cane-sugar.  The  correction  of  the  original  polarization 
in  such  cases  is  most  generally  made  by  the  method  of  inversion  pro- 
posed by  Clerget.  The  direct  polarization  is  taken  in  the  usual  way,  and 
a  part  of  the  solution  remaining  from  the  one  hundred  cubic  centimetres 
prepared  for  this  test  is  put  into  a  50-cubic-centimetre  flask,  which  has 
also  a  55-cubic-centimetre  mark  on  the  neck.  Fifty  cubic  centimetres 
having  been  taken,  five  cubic  centimetres  of  concentrated  hydrochloric 
acid  is  added,  and  the  whole  heated  on  a  water-bath  to  70°  C.  for  some 
ten  minutes.  This  suffices  to  completely  invert  the  cane-sugar  present, 
while  the  original  invert  sugar  is  unacted  on.  The  flask  is  then  cooled, 
and  part  of  the  liquid  is  filled  into  -a  220-millimetre  tube,  closed  by  glass 
plates  at  both  ends  and  provided  with  a  tubulure  in  the  side  so  that  a 
thermometer  may  hang  suspended  in  the  liquid  when  the  observation  is 
made.  The  reading  will  generally  be  much  reduced  from  the  original 
dextro-rotatory  reading,  and  may  even  be  some  degrees  to  the  left.  If, 
then,  8  represent  the  sum  or  difference  of  polariscope  readings  before 
and  after  inversion  (difference  if  both  are  to  the  right,  sum  if  the  second 
reading  is  to  the  left),  T  the  temperature  of  the  inverted  solution  when 

200  8 
polarized,  and  R  the  correct  percentage  sought,  E=         „  .     Clerget 

has  also  prepared  an  elaborate  set  of  tables  which  make  the  use  of  the 
formula  unnecessary.  (See  also  under  molasses,  p.  178.) 

(B)  Chemical  Methods. — The  only  chemical  method  for  the  deter- 
mination of  cane-sugar  ever  resorted  to  is  the  inversion  of  the  cane- 
sugar,  neutralizing  with  sodium  carbonate,  and  determination  of  the 
reducing  sugar  so  obtained  by  the  method  to  be  described  under  the  next 
head.  The  inversion  takes  place  in  definite  proportions,  so  that  nineteen 
parts  of  sucrose  produce  twenty  parts  of  the  invert  sugar.  When  in- 
vert sugar  is  also  present  in  the  solution  of  which  the  cane-sugar  is  to  be 
determined  by  inversion,  the  former  is  first  estimated  as  a  separate  opera- 
tion, and  then  a  portion  of  the  original  solution  is  inverted,  and  the  total 
invert  sugar,  including  that  formed  from  the  cane-sugar,  is  determined. 

2.  DETERMINATION  OP  GLUCOSE,  OB  INVERT  SUGAR. — The  oldest 
method  is  that  based  on  Trommer's  reaction  as  applied  to  sugar  analysis 
by  Barreswill  and  Fehling.  This  depends  upon  the  fact  that  an  alkaline 
solution  of  copper  oxide  containing  a  fixed  organic  acid,  as  tartaric,  is 
reduced  with  the  separation  out  of  insoluble  cuprous  oxide  by  dextrose, 
or  invert  sugar, "while  cane-sugar  has  no  effect.  The  composition  of  a 
standard  Fehling 's  solution,  as  it  is  called,  is  thus  given,*  34,639 
grammes  crystallized  copper  sulphate  are  dissolved  in  water  and 
brought  to  500  cubic  centimetres;  173  grammes  Rochelle  salt  and  50 
grammes  sodium  hydroxide  are  also  dissolved  In  water  and  brought  to 

*  Bulletin  No.  107,  Bureau  of  Chemistry,  U.  S.  Dept.  of  Agriculture, 


ANALYTICAL  TESTS  AND  METHODS.  175 

500  cubic  centimetres.  Equal  volumes  of  these  solutions  are  mixed 
when  required  for  use  and  constitute  the  correct  Fehling's  solution.  The 
ready-prepared  Fehling's  solution  changes  in  the  course  of  some  days 
in  effective  power  even  when  kept  in  a  cool  place  and  in  the  dark.  Ten 
cubic  centimetres  of  the  Fehling's  solution  given  above  correspond  to 
.05  gramme  dextrose,  or  invert  sugar,  or  .0475  gramme  cane-sugar  made 
active  by  inversion.  For  technical  determinations  merely  the  work  with 
the  solution  can  be  volumetric ;  for  more  exact  scientific  purposes  it  must 
be  gravimetric,  weighing  the  copper  as  metal  or  as  cupric  oxide.  In 
carrying  out  the  volumetric  test,  the  sugar  solution  in  which  glucose  is 
to  be  determined  is  placed  in  a  burette.  If  dark,  it  may  be  previously 
cleared  with  a  small  quantity  of  bone-black,  or  if  it  be  some  of  the  solu- 
tion prepared  for  polarization,  it  is  prepared  without  lead  solution,  an 
aliquot  portion  taken  out  for  this  glucose  determination,  and  the  re- 
mainder treated  with  a  measured  quantity  of  the  lead  solution,  for  which 
allowance  is  made.  Any  lead  in  this  glucose  solution  must  be  eliminated 
thoroughly.  This  is  best  done  with  sulphurous  acid,  the  change  ,of 
strength  in  the  liquid  being  noted.  Ten  cubic  centimetres  of  the  mixed 
Fehling's  solution  are  now  measured  into  a  porcelain  dish,  diluted  with 
twenty  or  thirty  cubic  centimetres  of  water  and  brought  quickly  to  boil- 
ing, when  the  sugar  solution  is  run  in  two  cubic  centimetres  at  a  time, 
boiling  between  each  addition.  When  the  blue  color  has  nearly  disap- 
peared the  sugar  solution  should  be  added,  in  small  amount  but  still 
rapidly.  The  end  of  the  reaction  is  reached  when  a  few  drops  of  the 
supernatant  liquid  filtered  into  a  mixture  of  acetic  acid  and  dilute  potas- 
sium ferrocyanide  give  no  brown  color. 

In  carrying  out  the  gravimetric  method  the  Fehling's  solution  re- 
mains in  excess,  while  the  precipitated  cuprous  oxide  is  carefully  filtered 
off  and  further  treated.  The  procedure  is  as  follows :  Sixty  cubic  centi- 
metres of  the  mixed  Fehling's  solution  and  thirty  cubic  centimetres  of 
water  are  boiled  up  in  a  beaker  glass,  twenty-five  cubic  centimetres  of 
the  dextrose  solution  of  approximately  one  per  cent,  strength  added,  and 
the  mixture  again  boiled.  It  is  then  filtered  with  the  aid  of  a  fiTterv^^ 
upon  a  Soxhlet  filter  (asbestos  layer  in  a  tared  funnel  of  narrow  cylinder 
shape),  quickly  washed  with  hot  water,  and  then  with  alcohol  and  ether, 
and  dried.  The  asbestos  filter,  with  the  cuprous  oxide,  is  now  heated 
with  a  small  flame,  while  a  current  of  hydrogen  is  passed  into  the  funnel, 
so  that  the  precipitate  is  reduced  to  metallic  copper.  It  is  allowed  to 
cool  in  the  current  of  hydrogen,  placed  for  a  few  minutes  over  sulphuric 
acid,  and  then  weighed.  A  table  has  been  constructed  by  Allihn  which 
gives  in  milligrammes  the  dextrose  corresponding  to  the  weight  of  copper 
found. 

Other  methods  for  the  determination  of  dextrose  are  those  of  Defren, 
who  determines  the  copper  as  cupric  oxide  (Leach,  Food  Inspection,  2d 
ed.,  p.  593)  ;  of  Munson  and  Walker,  who  weigh  the  copper  as  cuprous 
oxide  (Ibid.,  p.  598)  ;  and  of  Soldaini,  who  uses  a  solution  of  basic  car- 
bon'ate  of  copper  dissolved  in  potassium  bicarbonate.  This  last  reagent 
has  been  recently  strongly  commended  as  better  than  Fehling's  solution, 


176  THE  CANE-SUGAR  INDUSTRY. 

in  that  it  is  more  sensitive  to  glucose  and  is  much  less  affected  by  cane- 
sugar  even  after  prolonged  boiling.* 

3.  ANALYSIS  OF  COMMERCIAL  RAW  SUGARS. — Raw  sugars  contain,  be- 
sides the  cane-sugar,  invert  sugar,  moisture,  mineral  salts,  organic  non- 
sugar,  and  insoluble  matter.  Raw  beet-sugars  contain,  in  addition  to  the 
sucrose  and  glucose  just  mentioned,  small  quantities  of  raffinose,  a 
variety  of  sugar  found  in  the  beet  juice  and  present  in  all  the  products 
from  it. 

The  cane-sugar  present  is  partly  crystallized  and  partly  uncrystal- 
lizable.  Both  are,  of  course,  counted  together  in  the  polarization  figures, 
but  only  the  first  is  capable  of  extraction  in  the  refining  process.  The 
method  of  estimating  the  crystallized  cane-sugar  for  itself  will  be 
described  later  on.  The  polarization  methods  have  already  been  de- 
scribed. In  raw  sugars  containing-  much  invert  sugar,  such  as  those 
from  the  cane,  the  double  polarization  (before  and  after  inversion)  is 
alone  to  be  relied  upon. 

The  methods  for  glucose  have  also  been  described. 

The  determination  of  moisture  is  made  by  taking  five  grammes  of  the 
sample  and  drying  it  spread  out  on  a  weighed  watch-crystal  in  an  air- 
bath  not  over  100°  C.  until  it  ceases  to  lose  weight.  As  sugars  containing 
much  glucose  cannot  stand  the  heat  without  some  alteration,  in  their 
case  a  lower  temperature  (about  70°  C.)  is  used.  For  very  syrupy  sugars 
and  melados  it  becomes  necessary  to  dry  with  the  addition  of  a  weighed 
amount  of  clean  sand.  Drying  in  a  vacuum  is  also  practised  in  many 
cases,  as  the  operation  is  shortened  and  less  risk  of  alteration  exists. 

The  mineral  salts  are  determined  as  ash.  The  following  analyses 
give  the  average  composition  of  raw  cane-  and  beet-sugar  ash  according 
to  Monier: 

Cane-sugar.  Beet-sugar. 

Potassium  (and  sodium)  carbonate 16.5  82.2 

Calcium    carbonate    49.0  6.7 

Potassium   (and  sodium)   sulphate    16.0 

Sodium  chloride  9.0 

11.1 

Silica  and  alumina   9.5  None. 


100.0  100.0 

Owing  to  this  decided  difference  it  is  much  easier  to  get  the  ash  of 
cane-sugars  completely  burned  and  in  weighable  condition  than  that  of 
beet-sugars,  which  contain  so  much  of  the  deliquescent  and  alkaline  car- 
bonates. To  obviate  this  difficulty,  Scheibler  proposes  to  treat  the  sugar 
with  sulphuric  acid  before  igniting  it,  by  which  means  the  ash  obtained 
contains  the  bases  as  non-volatile,  difficultly  fusible  and  non-deliquescent 
sulphates  instead  of  as  carbonates.  A  deduction  of  one-tenth  of  the 
weight  of  the  sulphated  ash  must  be  made  in  this  case  for  the  increase 
due  to  the  sulphuric  acid.  -The  soluble  and  insoluble  ash  are  often  dis- 
tinguished in  addition  to  total  ash.  In  ordinary  commercial  analyses  of 

*  Bodenbender  und   Scheller,   Zeitschrift  fiir  Rlibenzucker,   1887,   p.   138. 


ANALYTICAL  TESTS  AND  METHODS.  177 

sugars,  the  sum  of  the  cane-sugar,  glucose,  ash,  and  water  is  subtracted 
from  one  hundred,  and  the  difference  called  organic  or  undetermined 
matters.  This  would  include  both  the  soluble  organic  impurities  and  the 
insoluble  impurities,  such  as  fibre  and  particles  of  cane.  Two  processes 
have  been  proposed  for  determining  the  soluble  organic  impurities  sepa- 
rately: Walkoff's  method  of  precipitation  with  tannin,  and  the  basic 
acetate  of  lead  method.  Neither  method  is  in  very  general  use. 

As  before  stated,  the  full  analysis  of  a  raw  sugar  will  not  give  any 
exact  measure  of  its  refining  value, — that  is,  of  the  amount  of  crystal- 
lized cane-sugar  that  can  be  extracted  from  it.  The  so-called  method  of 
coefficients  adopted  in  France,  whereby  five  times  the  ash,  plus  once  or 
twice  the  glucose  percentage  subtracted  from  the  cane-sugar  percentage, 
is  taken  to  represent  the  crystallized  cane-sugar  obtainable,  is  not  much 
to  be  depended  upon.  The  true  refining  value,  or  rendement,  of  a  raw 
sugar  can,  however,  be  determined  by  a  special  procedure  first  proposed 
by  Payen  and  afterwards  improved  by  Scheibler.  The  process  depends 
upon  the  fact  that  if  raw  sugars  be  treated  with  a  saturated  alcoholic 
solution  of  cane-sugar  acidified  with  acetic  acid,  the  coloring  matter  and 
other  impurities,  together  with  the  syrup  and  other  uncrystallizable  con- 
stituents, are  removed,  while  the  crystallized  sugar  remains  unchanged. 
The  sugary  alcoholic  liquids  are  then  displaced  by  absolute  alcohol.  Fig. 
52  shows  the  arrangement  of  vessels.  The  bottle  I  contains  eighty-five 
per  cent,  alcohol,  to  which  fifty  cubic  centimetres  of  acetic  acid  is  added 
per  litre,  and  the  mixture  allowed  to  stand  in  contact  with  an  excess  of 
powdered  white  sugar  for  a  day,  being  shaken  at  intervals;  bottle  II, 
alcohol  of  ninety-two  per  cent,  saturated  as  the  other,  but  without  acetic 
acid ;  bottle  III,  alcohol  of  ninety-six  per  cent.,  also  saturated  with  sugar ; 
and  bottle  IV,  a  mixture  of  two-thirds  absolute  alcohol  and  one-third 
ether.  Of  the  sugars  to  be  examined,  weights  are  taken  corresponding  to 
the  polariscope  used,  placed  in  the  upright  tubes,  washed  with  the  succes- 
sive solutions,  and  dried  by  the  aid  of  a  filter-pump  ready  for  use  in  the 
polariscope  test.  In  carrying  out  the  process,  the  alcohol  and  ether  mix- 
ture is  first  run  in  that  it  may  take  up  any  moisture  and  throw  out  the 
sugar  that  such  moisture  may  have  dissolved,  then  successively  down  to 
No.  I,  which  is  the  effective  washing  solution.  This  is  then  displaced  by 
Nos.  II,  III,  and  IV  in  succession.  The  method  is  thoroughly  reliable, 
but  great  care  must  be  taken  to  keep  the  alcoholic  solutions  just  satu- 
rated with  sugar  through  all  changes  of  temperature. 

4.  ANALYSES  OF  MOLASSES  AND  SYRUPS. — The  composition  of  both 
the  cane-sugar  and  the  beet-sugar  molasses  have  already  been  given  (see 
p.  169),  and  it  was  seen  that  they  differed  notably.  Both  still  contain 
considerable  quantities  of  sucrose,  but  for  different  reasons.  With  the 
cane-sugar  molasses  because  of  the  invert  sugar,  with  the  beet-sugar 
molasses  because  of  the  melassigenic  salts.  In  either  case  the  polari- 
scope reading  for  sucrose  must  be  corrected  by  inversion.  The  glucose 
is  determined  as  described  under  raw  sugars.  The  water  is  determined 
by  weighing  out  a  sample,  thinning  it  with  water,  putting  it  into  a 
weighed  dish  with  clean  sand,  and  drying  it  at  a  temperature  of  60°  C. 

12 


178 


THE  CANE-SUGAR  INDUSTRY. 


until  constant.  Drying  in  a  partial  vacuum  also  facilitates  the  drying 
off  of  the  moisture.  The  ash  is  determined  as  with  raw  sugars,  sulphuric 
acid  being  added,  and  the  bases  weighed  as  sulphates  instead  of  as  car- 
bonates, the  proper  correction  being  made.  The  organic  non-sugar  is 
simply  taken  by  difference  as  with  raw  sugars.  The  determination  of 
raffinose  in  raw  beet-sugars,  and  particularly  in  beet-molasses,  has  at- 
tracted much  attention  in  recent  years.  Creydt*  has  suggested  a  way  for 

FIG.  52. 


determining  it  in  the  presence  of  cane-sugar  in  connection  writh  the 
method  of  inversion.  He  finds  that  while  cane-sugar  polarizing  100°  to 
the  right  before  inversion  polarizes  32°  to  the  left  after  inversion,  a 
change  of  132°,  raffinose  changes  from  100°  to  50.7°  only,  a  change  of 
49.3°.  He  proposes  two  formulas:  A  =  z  -f  1.57  R,  and  c  =  1.322  -f 
1.57  E  X  -493,  in  which  A  is  the  direct  polarization,  c  the  polarization 
after  inversion,  z  the  percentage  of  cane-sugar,  and  R  that  of  raffinose. 

*  Zeitschrift  fiir  Riibenzucker,  vol.  xxxvii,  p.  163. 


ANALYTICAL  TESTS  AND  METHODS.  179 

From  these  formulas,  A  and  c  being  known,  z  and  R  can  be  found.    The 
reading  after  inversion  must  be  taken  uniformly  at  20°  C. 

5.  ANALYSES  OF  SUGAR-CANES  AND   SUGAR-BEETS  AND   RAW  JUICES 
THEREFROM. — The  very  different  physical  characters  of  the  sugar-cane 
and  the  sugar-beet,  the  one  a  bamboo-like  shell  enclosing  a  woody  pith, 
and  the  other  a  soft  root  easily  brought  into  pulpy  consistency,  make  the 
work  upon  them  quite  different.    In  the  case  of  the  cane,  the  samples  to 
be  analyzed  are  weighed  and  then  pressed  between  rolls,  moistened  with 
hot  water  and  again  pressed,  and  this  repeated  several  times.     The  ex- 
hausted stalk,  or  "bagasse,"  is  usually  not  further  examined,  but  in  the 
juice  the  sucrose,  glucose,  ash,  and  organic  non-sugar  are  determined  as 
before  described.     In  all  analyses  of  raw  cane  juices  the  percentage  of 
total  solids  is  determined  by  the  Brix  saccharometer  or  "spindle."    The 
form  of  hydrometer  in  most  general  use  is  known  as  the  Balling  or  Brix, 
and  its  readings  indicate  directly  the  percentage  of  impure  sugar  or  solid 
matter  dissolved.    Sets  of  tables  also  allow  of  the  conversion  of  the  Brix 
scale  into  direct  specific  gravity  figures.     (See  Appendix,  p.  570.)     With 
the  aid  of  the  specific  gravity  determination  it  is  possible  to  make  a  rapid 
analysis  of  raw  juice  without  weighing.    The  method  adopted  by  Cramp- 
ton,*  one  of  the  chemists  of  the  United  States  Bureau  of  Agriculture, 
for  this  analysis  is  to  measure  out  a  certain  volume  of  the  juice,  add 
lead  solution,  make  up  to  another  definite  volume,  polarize,  and  apply 
the  correction  for  specific  gravity  to  the  reading  obtained.     A  set  of 
tables  for  this  correction  and  the  factor  needed  in  the  glucose  deter- 
mination are  given  by  Crampton. 

In  the  examination  of  sugar-beets,  the  system  of  pressing  and  mois- 
tening with  hot  water  can  be  followed  for  the  extraction  of  the  juice, 
but  the  method  proposed  by  Scheibler  of  extracting  the  sugar  from  a 
weighed  quantity  of  the  pulp  by  the  aid  of  alcohol  is  much  better.  This 
is  accomplished  by  the  aid  of  a  Soxhlet  or  other  extractor  (see  p.  86) 
connected  with  an  upright  condenser.  After  complete  extraction  and 
cooling  the  necessary  amount  of  lead  solution  is  added,  and  the  liquid 
brought  up  to  the  mark  with  absolute  alcohol  and  then  polarized. 
Degener  has  described  a  still  simpler  form  of  extraction,  originally  sug- 
gested by  Rapp,  in  which  the  pulp  remains  in  the  alcoholic  solution  until 
after  it  is  cleared  with  the  lead  solution  and  brought  to  the  mark,  when 
it  is  filtered  and  polarized.  A  correction  must  in  this  case  be  applied 
to  the  reading  on  account  of  the  volume  occupied  by  the  pulp  in  the 
measured  liquid. 

The  amount  of  dry  residue,  or  "marc,"  of  the  beet  can  be  deter- 
mined in  the  Scheibler  extraction  method  at  the  same  time  by  taking 
the  exhausted  residue,  drying  it  in  a  current  of  air,  and  weighing  it. 
The  moisture  and  ash  of  the  beet  are  determined  as  with  raw  sugars. 
The  organic  non-sugar  is  gotten  by  difference  or  by  one  of  the  methods 
mentioned  under  raw  sugars. 

6.  ANALYSES  OF  SIDE-PRODUCTS. — (a)  Of  Bone-Black. — Careful  anal- 

*  United  States  Bureau  of  Agriculture,  Bulletin  No.  15,  pp.  31-35. 


180  THE  CANE-SUGAR  INDUSTRY. 

yses  of  both  fresh  char  and  that  which  is  in  use  are  needed  to  allow  of 
the  proper  control  in  filtration.  The  most  important  determinations  are 
those  of  water,  carbonate  of  lime,  carbon,  and  specific  gravity,  as  upon 
the  changes  in  these  depend  in  the  main  its  efficiency.  The  water  is 
determined  by  drying  for  several  hours  at  140°  C.  The  sample  should 
not  be  powdered.  The  carbon  is  determined  by  treating  a  weighed  quan- 
tity of  the  char  with  pure-  hydrochloric  acid,  with  the  aid  of  heat,  on  a 
water-bath  until  the  soluble  portions  have  been  dissolved,  diluting  and 
filtering  upon  a  weighed  quantitative  filter.  After  thorough  washing 
with  hot  water,  the  filter  and  contents  are  dried  at  100°,  placed  between 
watch-glasses  and  weighed,  again  heated  and  weighed  as  long  any  loss 
of  weight  is  shown.  The  filter  and  carbon  are  then  transferred  to  a 
weighed  crucible  and  ignited.  The  insoluble  residue,  taken  from  the 
previous  weight,  minus  the  weight  of -the  filter,  gives  the  amount  of  car- 
bon. The  estimation  of  carbonate  of  lime  in  case  the  char  is  used  with 
cane-sugar  or  juices  is  of  much  less  importance  than  when  the  char  is 
used  with  beet-sugars  or  juices.  In  the  former  case,  the  percentage 
decreases  at  first,  and  then  remains  nearly  stationary,  in  the  repeated 
use  of  the  char,  while  in  the  latter  case  it  would  increase  steadily,  because 
of  the  more  thorough  liming  and  carbonatation  to  which  the  beet  juices 
are  subjected,  were  it  not  for  the  treatment  with  hydrochloric  acid  in 
the  revivifying  of  the  char.  (See  p.  165.)  To  allow  of  the  proper  judg- 
ment in  this  use  of  hydrochloric  acid,  it  becomes  necessary  in  beet-sugar 
working  to  determine  carefully  the  amount  of  carbonate  of  lime  taken 
up  by  the  char  in  using  before  starting  the  revivification.  It  is  almost 
universally  done  at  present  by  the  aid  of  the  Scheibler  apparatus,  shown 
in  Fig.  53.  The  normal  quantity  of  pulverized  char  (1.702  grammes) 
is  placed  in  A,  and  the  tube  S  filled  with  acid  to  the  mark  is  carefully 
placed  in  the  bottle.  E  is  then  filled  with  water,  and  the  operator,  by 
means  of  the  compression-bulb,  forces  the  liquid  into  D  and  C,  which 
connect  at  the  base,  until  it  reaches  a  little  above  the  zero-point  in  C, 
when  it  is  allowed  to  flow  out  by  opening  the  pinchcock  at  p  until  the 
level  in  C  is  at  zero.  The  stopper  now  being  placed  in  A,  a  connection 
with  B  is  made  by  the  tube  r.  If  the  level  of  the  liquid  in  D  and  C 
be  then  unequal,  the  equality  may  be  restored  by  opening  the  cock  q 
for  a  few  seconds,  and  which  for  the  rest  of  the  operation  remains  closed. 
The  vessel  A  is  now  held,  as  shown  in  the  cut,  so  that  the  acid  may  come 
in  contact  with  the  char,  and  the  bottle  gently  shaken  to  cause  the  acid 
to  mix  thoroughly  with  the  assay.  The  pressure  of  the  gas  evolved  dis- 
tends the  rubber  bag  in  B  and  depresses  the  column  of  water  in  C.  The 
stopcock  p  is  now  opened  to  allow  the  water  in  D  to  flow  out  sufficiently 
rapidly  to  keep  the  level  in  C  and  D  as  near  the  same  as  possible  during 
the  progress  of  the  determination.  When  all  the  gas  has  been  given  off 
and  the  level  of  the  liquid  in  C  becomes  stationary,  p  is  closed,  after 
bringing  the  water  in  D  to  the  same  level  as  that^  in  C,  and  the  volume 
and  temperature  read  off.  A  set  of  tables  accompanying  the  instrument 
gives  the  percentage  of  carbonate  of  lime  from  the  volume  and  tempera- 
ture readings.  Assuming  seven  per  cent,  to  be  the  normal  amount  of  car- 


ANALYTICAL  TESTS  AND  METHODS. 


181 


bonate  of  lime  in  the  char,  any  excess,  as  shown  in  this  determination, 
can  have  its  equivalent  in  hydrochloric  acid  of  known  strength  calcu- 
lated, and  thus  the  acid  treatment  in  the  revivifying  process  can  be  made 

accurate. 

FIG.  53. 


In  determining  specific  gravity,  both  apparent  and  real  specific 
gravity  (the .latter  after  boiling  the  char  with  distilled  water  to  displace 
air)  are  to  be  taken. 


182  THE  CANE-SUGAR  INDUSTRY. 

(&)  Of  Scums,  Press-cakes,  and  Sucrates. — In  the  case  of  the  scums 
and  press-cakes  obtained  in  the  manufacture  of  raw  sugars,  their  chief 
value  is  in  the  lime  salts  they  contain,  which,  notably  in  the  case  of 
beet-sugars,  adapt  them  for  use  as  fertilizing  materials.  They,  however, 
contain  such  amounts  of  sugar,  either  mechanically  held,  or,  where  the 
carbonatation  process  has  been  used,  as  sucrates,  as  make  it  necessary  to 
determine  regularly  the  sucrose  in  them.  In  the  case  of  the  thin  scums 
from  cane-sugar  working,  the  determination  can  be  made  exactly  as  with 
an  impure  juice  before  described.  In  the  case  of  the  heavier  press-cake 
from  beet-sugar  working,  resulting  from  carbonatation,  the  procedure  is 
different.  Here  the  sucrate  of  lime  is  to  be  decomposed  if  possible  with- 
out decomposing  the  large  amount  of  accompanying  carbonate  of  lime. 
This  is  done  by  careful  addition  of  acetic  acid,  controlling  the  reaction 
with  phenol-phthale'in.  For  details  of  this  process,  first  proposed  by 
Sidersky,  see  Friihling  and  Schultz,  "Anleitung  ziir  Zucker  Untersuch- 
ungen,"  3d  ed.,  p.  171. 

Sucrates,  resulting  from  the  working  of  molasses  for  sugar  by  either 
of  the  lime  or  strontium  processes  (see  p.  162),  are  analyzed  by  a  some- 
what similar  procedure,  using  strong  acetic  acid  to  set  the  sugar  free 
from  its  combination  with  the  lime  or  strontia  and  phenol-phthalein  as 
an  indicator.  The  excess  of  acid  is  afterwards  neutralized,  lead  solution 
added,  the  solution  brought  to  strength,  and  polarized.  (Ibid.,  p.  155.) 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

1877. — Tropical  Agriculture,  P.  L.  Simmons,  London. 

1881-90. — Bulletins  of  the  United  States  Department  of  Agriculture  on  Sugar  Ex- 
periments, Washington. 
1882. — Report  on  Sorghum-Sugar  by  the  National  Academy  of  Sciences,  Washington. 

Foods,  Composition  and  Analysis,  A.  W.  Blyth,  London. 

Traite  de  la  Fabrication  du  Sucre,  Horsin-D6on,  Paris. 
1884. — Guide  pour  1'Analyse  brute  Melasse,  etc.,  Commerson  et  Langier,  Paris. 

Sorghum,  its  Culture  and  Manufacture,  P.  Collier,  Cincinnati. 
1887. — Lehrbuch  der  Zuckerfabrikation,  C.  Stammer,  2te  Auf.,  Braunschweig. 
1888. — Handbuch  der  Kohlenhydrate,   B.  Tollens,  Breslau. 

Die  Chemie   der  Menschlichen   Nahrungs   und   Genussmittel,   J.    Konig,    3te 
Auf.,   Berlin  and  New  York. 

Sugar:  A  Hand-Book  for  Planters  and  Refiners,  Lock  and  Newlands,  London. 

Manuel  pratique  du  Fabricant  de  Sucre,  P.  Boulin,  Paris. 

1890. — Sugar  Analysis  for  Refineries,   Sugar-Houses,  etc.,  F.  G.   Wiechmann,   New 
York. 

Geschichte  des  Zuckers,  E.  O.  von  Lippmann,  Leipzig. 

A  Guide  to  the  Literature  of  Sugar,  H.  L.  Roth,  London. 
1891. — Anleitung  zur   Untersuchungen   der   Zuckerindustrie,   Fruhling  und  Schultz, 

4te  Auf.,  Braunschweig. 

1892. — Leitfaden  fiir  Zuckerfabriken-Chemiker,  E.  Preuss,  Berlin. 
1893. — Handbuch  der  Zuckerfabrikation,  F.  Stohmann,  <5te  Auf.,  Berlin. 

Manual  for  Sugar-Growers,  Fr.  Watts,  London. 
1894. — Die  Zuckerfabrikation,  Dr.  B.  von  Posanner,  Wien. 

La  Sucre  et  1'Industrie  sucrifcre,  Horsin-Deon,   Paris. 

Manual  of  Sugar  Analysis,  J.  H.  Tucker,  4th  ed.,  New  York. 


BIBLIOGRAPHY  AND  STATISTICS. 


183 


1895. — Die  Zuckerarten  und  ihre  Derivate,  E.  von  Lippmann,  2te  Auf.,  Braunsch- 
weig. 

Handbuch  der  Kohlenhydrate,  B.  Tollens,  2te  Bd.,  Breslau. 

1897. — Hand-Book  for  Sugar  Manufacturers,  etc.,  G.  L.  Spencer,  3d  ed.,  New  York. 
Hand-Book  for  Chemists  of  Beet-Sugar  Houses,  G.  L.  Spencer,  New  York. 
Beet-Sugar  Analysis,  E.  S.  Peffer,  Chino,  California. 
1898. — Sugar-Beet  Seed  for  Farmers,  etc.,  L.  S.   Ware,  New  York. 

Das   Optische   Drehungsvermogen   Organischer    Substanzen,    H.   Landolt,    2te 

Auf.,    Braunschweig. 
1906. — Beet  Sugar  Manufacture,  H.  Classen,  translated  from  2nd  German  Edition 

by  W.  T.  Hall  and  G.  W.  Rolfe,  New  York. 

1907. — Beet  Sugar  Manufacture  and  Refining,  L.  S.  Ware,  2  vols.,  New  York. 
1909.— Sugar:  A  Handbook  for  Planters  and  Refiners,  J.  A.  R.  and  B.  E.  R.  New- 
lands,  2nd  Edition,  E.  &  F.  N.  Spon,  London. 
Cane  Sugar  and  Its  Manufacture,  H.  C.  Prinsen-Gurligs,  Norman  Rodger, 

Manchester,  England. 

Beet  Sugar-making  and  Its  Chemical  Control,  Y.  Niceido,  Easton,  Pa. 
1911. — Cane  Sugar:    A  Text-book  on  the  Agriculture  of  the  Sugar   Cane  and  the 
Manufacture  of  Cane  Sugar,  Noel  Drew,  Sugar  Technologist,  Hawaii;    Man- 
chester, England. 


STATISTICS. 

1.  SUGAK  PRODUCTION  OF  THE  UNITED  STATES. — The  U.  S.  Census  of 
1910  gives  the  production  as  well  as  importations  of  sugar  for  1909  as 
compared  with  the  figures  for  the  three  previous  decades : 

A.      SUGAE    FROM    CANE    IN    1909. 

Louisiana  325,500  short  tons. 

Texas     8,600  short  tons. 


334,100  short  tons. 


B.     SUGAR  FROM  BEETS  IN  1909. 


California   

Granulated 
sugar 
(tons). 

126,600 

Raw 

sugar 
(tons). 

200 

Molasses 
(gallons)  . 

2,13-5,800 

Colorado    

147,000 

1,600 

7,669,200 

Michigan        

103,900 

600 

5,016,700 

\Visconsin   

13,000 

832,400 

All   other   States    

106,300 

2,500 

5,158,700 

Total    496,800 


4,900 


20,812,800 


C.    COMPARISON  OF  PRODUCTION  AND  IMPORTS. 

Imports  (in  tons). 


Production  (in  tons). 
Cane. 


1909  334,100 

1899  161,300 

1889  150,600 

1879  89,400 


Beet. 
501,700 
81,700 
2,500 
1,400 


Total. 
835,800 
243,000 
153,100 

90,800 


Non- 
contiguous 
U.S. 

Other 
countries. 

Total. 

927,800 

1,959,300 

2,887,100 

313,400 

1,695,600 

2,009,000 

280,600 

1,186,400 

1,467,000 

139,200 

775,400 

914,610 

184 


THE  CANE-SUGAR  INDUSTRY. 


2.  PRODUCTION,   IMPORTATION,   AND   CONSUMPTION  FOR  THE  UNITED 
STATES  IN  1910. — The  Bureau  of  Statistics  reports  for  the  year  ending 
June  30,  1910,  as  follows: 

1910  (tons).  1909  (tons). 

Production  of  sugar  from  cane  (in  tons)   362,500  414,500 

Production  of  sugar  from  beet   (in  tons)    512,500  483,500 

Total  production  in  United  States    887,500  898,500 

Hawaii    555,500  511,500 

Porto  Rico    284,500  244,000 

Philippines    88,000  42,000 

Total  from  U.  S.  dependencies 928,000  797,500 

Total  from  U.  S.  and  dependencies 1,815,500  1,695,500 

Importation  from  Cuba   1,755,000  

Importation  from  Dutch  Indies   157,500  

Total  imports   1,959,000  2,053,800 

Consumption  for  1910,  7550  million  pounds  =  82  pounds  per  capita. 

3.  SUGAR-BEETS  WORKED  AND  BEET-SUGAR  PRODUCED  IN  EUROPE. 

Sugar-beets  worked  (tons).  Beet-sugar  produced  (tons). 

1910-11.                   1909-10.                   1910-11.  1909-10. 

Germany    15,275,380         12,904,795         2,424,840  2,027,272 

Austria-Hungary    9,981,400           8,166,100         1,529,800  1,245,608 

France    5,383,000           6,246,850            703,330  803,006 

Belgium    1,932,000           1,777,600            271,800  248,403 

Holland    1,523,000           1,330,000            221,400  194,822 

Russia    13,080,400           6,837,498         2,085,200  1,123,594 

Sweden   1,088,300              897,000            167,160  127,000 

Denmark    750,000              500,000            105,000  65,000 

Italy    1,500,000              970,000            170,000  118,900 

Spain    490,000              667,000              60,000  83,000 

Rumania  275,000              208,000              35,000  30,775 

Servia 75,000                66,000              10,000  8,630 

Bulgaria    35,000                20,000               4,200  2,435 

Switzerland    25,000                25,000                3,500  3,500 


51,413,480         40,415,843         7,791,330         6,081,945 


RAW  MATERIALS.  185 


CHAPTER   V. 

THE   INDUSTRIES   OF   STARCH   AND   ITS   ALTERATION   PRODUCTS. 

I.  Raw  Materials. 

STARCH  is  one  of  the  most  important,  as  well  as  most  widely  occur- 
ring, productions  of  the  vegetable  kingdom.  It  constitutes,  either  when 
extracted  from  vegetable  raw  materials,  or  more  generally  in  admixture 
with  the  other  plant  constituents,  the  staple  article  of  food  for  the  great 
bulk  of  the  human  race.  It  is  only  necessary  to  call  attention  to  the  fact 
that  the  principal  cereal  grains  used  throughout  the  world  for  food  con- 
tain starch  as  their  chief  ingredient,  and  that  the  tubers  of  many  plants 
and  the  stems  and  roots  of  some  trees  also  yield  starch  in  great  abundance. 

The  most  complete  enumeration  and  classification  of  starches  is  that 
of  Muter  as  amplified  by  Allen*  and  Blyth,f  by  which  they  are  divided 
into  five  groups  on  the  basis  of  their  physical  and  microscopical  differ- 
ences, as  follows: 

I.  The  potato  group  includes  such  oval  or  ovate  starches  as  give  a 
play  of  colors  when  examined  by  polarized  light  and  a  selenite  plate  and 
having  the  hilum  and  concentric  rings  clearly  visible.     It  includes  tout 
les  mois,  or  canna  arrow-root,  potato  starch,  maranta,  or  St.  Vincent 
arrow-root,  Natal  arrow-root,  and  curcuma  arrow-root. 

II.  The  leguminous  starches  comprise  such  round  or  oval  starches  as 
give  little  or  no  color  with  polarized  light,  have  concentric  rings  all  but 
invisible,  though  becoming  apparent  in  many  cases  on  treating  the  starch 
with  chromic  acid,  while  the  hilum  is  well  marked  and  cracked,  or  stel- 
late.   It  includes  the  starches  of  the  bean,  pea,  and  lentil. 

III.  The  wheat  group  comprises  those  round  or  oval  starches  having 
both  hilum  and  concentric  rings  invisible  in  the  majority  of  granules.    It 
includes  the  starches  of  wheat,  barley,  rye,  chestnut,  and  acorn,  and  a 
variety   of   starches    from   medicinal   plants,   such   as   jalap,    rhubarb, 
senega,  etc. 

IV.  The  sago  group  comprises  those  starches  of  which  all  the  gran- 
ules are  truncated  at  one  end.     It  includes  sago,  tapioca,  and  arum, 
together  with  the  starch  from  belladonna,  colchicum,  scammony,  podo- 
phyllum,  canella,  aconite,  cassia,  and  cinnamon. 

V.  The  rice  group.     In  this  group  all  the  starches  are  angular  or 
polygonal  in  form.    It  includes  oats,  rice,  buckwheat,  maize,  dari,  pepper, 
as  well  as  ipecacuanha. 

In  addition  to  the  differences  in  form  and  marking  mentioned  above, 

*  Com.   Org.   Anal.,   2d   ed.,   vol.   i,   p.   335. 
t  Blyth,  Foods,  Compos,  and  Anal.,  p.  139. 


186 


STARCH  AND  ITS  ALTERATION  PRODUCTS. 


the  starch-granules  differ  in  size  according  to  their  different  sources,  so 
that  under  the  microscope  they  can  be  distinguished  by  the  measure- 
ment of  the  average  diameter  of  the  granule.  This  ranges,  according  to 
Karmarsch,  from  .01  to  .815  millimetre,  or  from  .0004  to  .0079  inch. 

For  practical  purposes  we  may  now  speak  of  two  classes  only  of  these 
starch-containing  materials, — vix.,  the  cereals  and  the  plants  in  which 
the  starch  is  extracted  from  tubers,  roots,  or  stems,  such  as  potatoes  on 
the  one  hand,  and  the  West  Indian  starch  preparations,  like  arrow-root, 
sago,  and  tapioca,  on  the  other.  As  before  stated,  starch  is  the  chief 
ingredient  in  the  cereals,  but  not  at  all  the  only  one.  The  composition 
of  the  more  important  cereals  is  thus  given  by  Bell  :* 


CONSTITUENTS. 

Wheat. 
Winter 
sown. 

Wheat. 
Spring 
sown. 

Long- 
eared 
barley. 

English 
oats. 

Maize. 

.Rye. 

Carolina 
rice 
(without 
husk). 

Fat    

1.48 

1.56 

1.03 

5.14 

3.58 

1.43 

0.19 

Starch  

63.71 

65.86 

63.51 

49.78 

64.66 

61.87 

77.66 

Sugar  (as  sucrose)    

2.57 

2.24 

1.34 

2.36 

1.94 

4.30 

0.38 

Albumen  (insoluble  in  alcohol)  

1070 

7.19 

8.18 

10.62 

9.67 

9.78 

7.94 

Nitrogenous  matter  (soluble  in  alcohol)  . 
Cellulose     

4.83 
303 

4.40 
293 

3.28 

7.28 

4.05 
13.53 

4.60 
1.86 

5.09 
3.23 

1.40 
Traces. 

Mineral  matter    

160 

1.74 

2.32 

2.66 

1.35 

1.85 

0.28 

Moisture  

12.08 

14.08 

13.06 

11.86 

12.34 

12.45 

12.15 

Total  

10000 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

The  chemical  formula  of  starch  is  (C6H1005)n.  According  to  Tollens, 
confirmed  by  Mylius,  it  is  C24H40O20 ;  according  to  Brown  soluble  starch 
is  C120H200O100,  while  for  the  ordinary  variety  he  proposes  C180H300O15a. 
Nageli  stated  that  by  subjecting  the  starch-granules  to  the  slow  action 
of  saliva,  salt  solutions,  and  dilute  acids  two  substances  could  be  shown 
to  be  present,  granulose,  which  dissolved,  and  cellulose  (or,  as  it  has  been 
called,  farinose},  which  remained.  Arthur  Meyer  considers  that  there 
is  only  a  single  substance  originally  present,  and  that  the  cellulose,  or 
farinose,  which  remains  is  a  decomposition  product  of  the  starch. 

Air-dried  starch  always  retains  from  eighteen  to  twenty  per  cent,  of 
water.  It  is  soluble  in  cold  water,  alcohol,  ether,  ethereal  and  fatty  oils. 
When  it  is  heated  with  twelve  to  fifteen  times  its  bulk  of  water  to  55°  C., 
it  begins  to  show  signs  of  change,  swelling  up,  and  at  a  temperature 
of  from  70°  to  80°  C.  (or  even  below  70°  C.  with  some  pure  starches) 
the  granules  burst  and  it  becomes  a  uniform  translucent  mass,  known 
as  ' '  starch-paste, ' '  which  is  not,  however,  a  solution,  as  the  water  can  be 
frozen  out  of  it.  Boiled  with  water  for  a  long  time  it  goes  into  solution, 
one  part  dissolving  in  fifty  parts  of  water.  The  action  of  heat  upon 
starch  is  to  change  it  gradually  into  dextrine,  which  is  soluble  in  cold 
water. 

One  of  the  best  known  of  the  reactions  of  starch  is  the  formation  of  a 
blue  color  with  iodine.  This  has  been  carefully  studied  by  L.  W.  An- 
drews (Jour.  Amer.  Chem.  Society,  1902,  p.  865),  who  considers  it 

*  Bell,  The  Analysis  and  Adulteration  of  Foods,  Part  ii,  p.  86. 


PROCESSES  OF  MANUFACTURE.  187 

to  be  a  dissociable  addition  compound  of  iodine  with  starch  molecules. 
He  finds  that  clear  starch  solutions  made  at  a  temperature  of  about  150° 
take  up  in  the  cold  an  amount  of  iodine  corresponding  to  the  formula 
(C6H1003)12I,  while  starch  heated  with  excess  of  iodine  to  100°  for  a 
short  time  takes  up  an,  amount  of  iodine  corresponding  to  the  formula 
(CGH10O5)12I2.  The  blue  coloration  is  constantly  availed  of  to  note  the 
presence  or  gradual  disappearance  or  alteration  of  starch  in  many  tech- 
nical processes. 

The  action  of  dilute  acids  upon  starch  brings  about  the  change  known 
as  "hydrolysis,"  and  there  is  produced  dextrine,  C12H20010,  and  dex- 
trose, C6H12OG,  the  latter  eventually  as  sole  product.  Many  ferments, 
like  saliva,  the  pancreatic  ferment,  and  especially  the  diastase  of  malt, 
produce  in  starch  a  somewhat  similar  change  and  yield  maltose,  C12H.,2O11, 
and  a  number  of  intermediate  products  between  this  and  starch.  A  great 
deal  of  investigation  has  been  devoted  to  these  intermediate  products, 
and  as  yet  no  absolute  agreement  has  been  reached  on  the  subject.  The 
following  is  the  series  of  products  obtained  in  this  hydrolysis  of  starch 
as  stated  by  Tollens:* 

Starch  gives  a  blue  iodine  reaction. 

Soluble  starch  (amylodextrine) gives  a  blue  iodine  reaction. 

(erythrodextrine gives  a  violet  and  red  iodine  reaction, 
achroodextrine gives  no  iodine  reaction, 
maltodextrine gives  no  iodine  reaction. 

Maltrose reduces  Fehling's  solution,  but  not  Barfoed's  reagent. 

Dextrose reduces  Fehling's  solution,  and  also  Barfoed's  reagent. 

Other  chemists  notably  increase  the  list  of  these  intermediate  prod- 
ucts. The  existence  of  erythrodextrine  as  a  distinct  compound  is  doubted 
by  some  investigators,  who  consider  it  to  be  merely  a  mixture  of  achroo- 
or  maltodextrine  with  a  little  soluble  starch,  such  a  mixture  giving  a 
violet  reaction  with  iodine.  By  over-treatment  with  acids  unferment- 
able  carbohydrates,  of  a  character  differing  from  any  of  the  products 
named,  appear  to  form.  The  name  gallisin  has  been  given  to  a  com- 
pound of  this  kind,  and  the  formula  C12H24010  ascribed  to  it.  For  a 
description  of  the  conditions  of  its  formation  see  later  (p.  197). 

Strong  nitric  acid  in  the  cold  acts  upon  starch,  producing  nitro  deriv- 
atives, such  as  mono-,  di-,  and  tetra-nitro  starch,  analogous  to  the  nitro- 
celluloses.  Alkalies  and  alkaline  earths  form  combinations  with  starch, 
the  barium  and  calcium  compounds  being  insoluble,  of  which  advantage 
is  taken  in  the  Asboth  method  for  determination  of  starch.  (See  p.  199.) 

n.  Processes  of  Manufacture. 

1.  EXTRACTION  AND  PURIFYING  OP  THE  STARCH. — Of  the  various 
starch-containing  materials  before  enumerated,  only  a  limited  number 
are  actually  utilized  for  the  extraction  of  the  starch  in  a  pure  condition, — 

*  Tollens,  Kohlenhydrate,  Breslau,  1888,  p.  177. 


188  STARCH  AND  ITS  ALTERATION  PRODUCTS. 

viz.,  maize,  wheat,  rice,  potatoes,  and  arrow-root.  In  the  United  States 
by  far  the  greater  amount  is  obtained  from  maize,  or  Indian  corn,  a 
limited  amount  only  being  extracted  from  wheat.  In  Europe,  on  the 
Continent,  potatoes  serve  as  the  chief  starch-producing  material,  some  also 
being  extracted  from  wheat  and  some  from  rice,  while  in  the  West  Indies 
arrow-root  starch  is  manufactured  at  St.  Vincent  and  elsewhere. 

In  the  manufacture  of  corn  starch,  after  winnowing  or  cleansing  the 
corn  by  powerful  fans,  it  is  placed  in  large  wooden  steeping-vats,  holding 
several  thousand  bushels  of  corn,  and  is  covered  with  warm  water  at 
about  140°  F.,  to  which  is  frequently  added  sulphur  dioxide,  making  a 
solution  of  1°  B.  sulphurous  acid.  After  twelve  hours  this  water  is  run 
off  and  the  germ  is  separated  after  a  crushing  of  the  softened  corn. 
While  the  germ  is  afterwards  worked  for  the  corn  oil  contained,  the 
starchy  portion  is  ground  again  and 'passes  on  to  the  separator  tables, 
where  it  is  continuously  washed.  These  separator  tables  are  inclined 
sieves  of  silk  bolting-cloth,  which  are  kept  in  constant  motion  and  are 
sprayed  with  jets  of  water.  The  starch  passes  through  the  bolting-cloth 
with  water  as  a  milky  fluid,  while  the  coarser  cellular  tissue,  or  husk, 
of  the  corn  is  left  behind.  This  residue  is  pressed  to  remove  water,  and 
sold  as  cattle  food.  The  water  from  the  shakers  holding  the  starch  in 
suspension  is  run  into  wooden  vats,  where  the  starch  settles,  and  the 
water  is  drawn  off  and  discarded.  The  starch  is  next  thoroughly  agitated 
with  fresh  water,  to  which  a  caustic  soda  solution  of  7°  to  8°  Baume  has 
been  added,  until  the  milky  liquid  has  changed  to  a  greenish-yellow 
color.  The  object  in  adding  the  alkali  is  to  dissolve  and  remove  the 
gluten  and  other  albuminoids,  oil,  etc.  After  sufficient  agitation  and 
treatment  with  alkali,  the  separated  starch  and  glutinous  matter  is 
allowed  to  deposit,  the  supernatant  solution  of  gluten,  oil,  etc.,  is  allowed 
to  run  to  waste,  and  the  impure  starch  washed  and  agitated  with  water. 
It  is  allowed  to  stand  at  rest  for  fifteen  to  twenty  minutes  to  permit  in- 
soluble gluten  to  subside,  when  the  top  one  of  a  series  of  plugs  arranged 
in  the  side  of  the  vat  is  withdrawn,  and  the  starch  suspended  in  water 
allowed  to  flow  by  means  of  a  gutter  into  subsiding- vats  placed  below; 
then  the  next  lower  plug  is  drawn,  and  so  on  until  the  last  plug  has  been 
drawn.  The  plugs  are  replaced  and  the  vats  again  filled  with  water,  and 
the  operation  repeated  as  before.  This  operation,  called  the  siphoning 
process,  is  generally  repeated  three  times,  and  the  three  runnings  of 
starch  are  collected  in  three  separate  vats,  forming  the  three  grades  of 
starch  of  the  factory.  These  three  grades  of  factory  starch  are  again 
agitated  with  water,  sieved  through  bolting-cloth,  and  run  finally  as 
purified  starch  into  wooden  "settlers."  After  it  has  been  compacted 
sufficiently,  which  is  effected  in  boxes  with  perforated  bottoms,  it  is  cut 
into  blocks  and  dried  upon  an  absorbent  support  of  plaster  of  Paris 
while  heated  in  a  current  of  warm  air.  In  drying  out  thoroughly,  any 
remaining  impurities  come  to  the  surface  with  the  escaping  moisture  and 
form  a  yellowish  crust.  When  this  is  removed,  the  interior  is  found  to 


PROCESSES  OF  MANUFACTURE.  189 

be  perfectly  white.     The  results  on  a  bushel  of  fifty-six  pounds  of  corn 
are  thus  stated  by  Archbold:* 

Starch  recovered    28.000  pounds. 

Dry  refuse  for  cattle  food    13.700  " 

Bran   (in  cleansing  process) 0.728  " 

Moisture  of  the  corn 5.626  " 

Loss  (albuminoids,  oil,  etc.) 7.946  " 


56.000 

Besides  this  very  complete  treatment  known  as  the  "alkali  process," 
much  of  the  cheaper  grade  of  starch  is  purified  by  the  use  of  sulphurous 
acid  alone  without  the  use  of  any  alkali,  and  this  product  is  known  as 
"acid  process  "  starch. 

In  either  case  the  removal  of  the  germ  as  a  preliminary  step  is  now 
practised,  as  from  this  is  obtained  the  valuable  maize  oil  together  with 
oil  cake  and  ground  husk  for  cattle  food.  The  starch  is  moreover  ob- 
tained in  a  higher  state  of  purity  and  the  process  considerably  shortened, 
lessening  the  danger  of  fermentation  or  souring  while  being  treated. 

In  manufacturing  starch  from  wheat  two  quite  different  processes 
are  followed,  according  as  the  gluten  is  to  be  obtained  as  a  side-product 
or  not.  In  the  process  generally  known  as  the  ' '  sour, ' '  or  fermentation, 
process,  the  gluten  is  wasted.  In  this  process  the  wheat  is  steeped  in 
tanks  until  thoroughly  softened,  then  crushed  in  roller-mills,  and  placed 
for  fermentation  in  large  oaken  cisterns.  The  temperature  is  here  main- 
tained at  about  20°  C.,  and  the  operation  lasts  some  fourteen  days,  the 
mass  being  well  stirred  during  its  continuance.  The  sugar  of  the  wheat 
and  a  part  of  the  starch  are  converted  into  glucose,  which  undergoes 
alcoholic  fermentation,  and  passes  by  oxidation  into  the  acetous  fermen- 
tation also,  acetic,  propionic,  and  lactic  acids  being  formed.  These 
rapidly  attack  and  dissolve  the  gluten,  liberating  the  starch-granules. 
The  impure  liquor  is  drawn  off  from  the  starch  mass,  and  the  latter  is 
washed,  either  in  hempen  sacks  while  being  trodden  under  foot  or  in 
drums  with  perforated  sides.  After  repeated  washings  and  settlings  and 
renewed  sieving  through  fine  hair  sieves  the  starch  is  sufficiently  purified. 
Wheat  starch  is  also  obtained  from  wheat  flour  without  fermen- 
tation by  what  is  known  as  Martin's  process,  in  which  a  stiff  dough 
is  made  of  the  flour.  This  is  then  washed  in  a  fine  sieve  under  a  jet  of 
water  till  all  the  starch  has  escaped  as  a  milky  fluid.  This  leaves  the 
gluten,  of  which  about  twenty-five  per  cent,  of  the  weight  of  the  flour 
is  gotten  suitable  for  use  in  the  manufacture  of  macaroni,  or  to  be  used 
instead  of  albumen  or  casein  in  calico-printing. 

In  the  manufacture  of  potato  starch,  the  potatoes  are  washed  and 
then  pulped  by  a  grating  or  rasping  machine.  The  grated  mass,  made 
into  a  paste  with  water,  then  goes  at  once  into  the  sieving  machine,  where 
it  is  rubbed  by  revolving  brushes  against  the  wire  or  hair  sides  of  the 

*  Journ.  Soc.  Chem.  Ind.,  1887,  p.  82. 


190 


STARCH  AND  ITS  ALTERATION  PRODUCTS. 


rotating  cylinder,  while  a  current  of  water  is  continuously  washing  out 
the  fine  starch  from  the  pulp.  The  sifted  and  washed  starch  deposits 
in  large  tanks,  where  it  is  repeatedly  Washed  by  agitation  and  settling 
with  fresh  waters.  It  is  then  spread  out  on  absorbent  slabs  to  dry,  or 
dried  in  drying  chambers  or  kilns  heated  by  steam  coils. 

2.  MANUFACTURE  OF  GLUCOSE,  OR  GRAPE-SUGAR. — As  stated  on  a  pre- 
ceding page,  the  action  of  dilute  acids  converts  starch  into  dextrine, 
maltose,  and  dextrose,  the  last  of  which  becomes  by  continued  action  the 
sole  product.  As  it  is  also  the  most  important  product  of  this  action  of 
acids,  we  shall  take  it  up  first.  The  purified  starch  obtained  as  described 
in  the  preceding  section,  while  yet  moist,  is  taken  for  the  treatment  with 

FIG.  54. 


acids.  The  "conversion  "  can  be  accomplished  in  either  open  or  closed 
converters,  although  the  former  have  been  practically  entirely  super- 
seded by  the  pressure  or  closed  converters.  These  converters  are  large, 
upright  vessels  of  iron  or  copper  lined  with  sheet  lead  to  prevent  the  ac- 
tion of  the  dilute  acids.  Sulphuric  acid  is  generally  employed  in  the  con- 
version if  a  solid  grape-sugar  is  to  be  made,  or  hydrochloric  acid  prefer- 
ably when  glucose  syrup  is  the  product  to  be  manufactured.  Both  oxalic 
acid  and  hydrofluoric  acid  have  been  used  in  France  as  the  agents  for 
the  conversion.  The  quantity  of  the  acid  employed  varies  with  the  object 
of  the  manufacturer.  For  the  production  of  ' '  glucose, ' '  a  liquid  product 
which  contains  much  dextrine,  a  smaller  quantity  is  used  than  when  solid 
"grape-sugar  "  is  to  be  produced,  in  which  the  conversion  into  dextrose 


PROCESSES  OF  MANUFACTURE. 


191 


is  much  more  complete.  The  proportion  varies  from  one-half  pound  oil 
of  vitriol  to  one  and  a  quarter  pounds  per  hundred  pounds  of  starch. 
When  the  open  converter  is  used,  a  few  inches  of  water  is  introduced  and 
the  acid  added,  or  half  the  acid  may  be  added  to  the  starch  mixture. 
The  acid  water  is  brought  to  a  boil,  and  the  starch,  previously  mixed 
with  water  to  a  gravity  of  from  18°  to- 21°  Baume,  is  slowly  pumped  in, 
keeping  the  liquid  constantly  boiling.  When  all  the  starch  has  been 
introduced,  the  whole  is  boiled  until  the  iodine  test  ceases  to  give  a  blue 
color  and  shows  a  dark  cherry  color.  The  boiling  is  usually  continued 
for  about  four  hours.  The  closed  converters  may  be  made  from  strong 
wooden  vats  or  may  be  of  copper;  they  are  provided  with  safety-valves, 
and  are  made  of  sufficient  strength  to  stand  a  pressure  of  six  atmos- 
pheres. Fig.  54  shows  the  form  first  introduced  in  this  country  by  T.  A. 
Hoffmann,  while  Fig.  55  shows  the  form  proposed  by  Maubre  in  London. 
In  this  case  the  starch  is  mixed  with  water  to  a  gravity  of  from  11°  to 

FIG.  55. 


16°  Baume.  This  with  the  acid  is  introduced  into  the  converter,  and 
the  whole  is  heated  under  a  pressure  of  from  forty-five  to  seventy-five 
pounds  per  square  inch.  The  time  required  for  the  conversion  is  much 
shorter  than  in  the  open  converters.  The  use  of  open  and  closed  con- 
verters successively  is  often  resorted  to.  The  starch  and  water  of  a 
gravity  of  15°  or  16°  Baume  is  first  boiled  in  the  open  converter  for 
from  one  to  two  hours,  then  transferred  to  the  closed  converter  and 
boiled  under  a  pressure  of  from  forty-five  to  seventy-five  pounds  per 
square  inch.  The  time  of  this  boiling  varies  from  ten  minutes  to  half 
an  hour. 

When  the  starch  has  been  sufficiently  converted,  according  to  the 
product  desired,  the  liquor  is  run  into  the  neutralizing-vats.  Here  a 
sufficient  quantity  of  marble-dust  is  added  to  completely  neutralize  the 
sulphuric  acid  (or  when  hydrochloric  acid  has  been  used,  a  solution  of 
caustic  soda).  A  little  fine  bone-black  is  generally  added  at  the  same 
time.  The  liquor  having  a  gravity  of  12°  to  18°  Baume,  and  known  as 
"light  liquor,"  is  next  filtered  through  bag  filters  of  cotton  cloth  or 
filter-presses.  In  many  establishments  the  liquor  is  now  treated  with  sul- 
phurous acid  gas  to  prevent  fermentation,  and  probably  to  some  extent 


192  STARCH  AND  ITS  ALTERATION  PRODUCTS. 

to  act  as  a  bleaching  agent.  It  is  then  filtered  through  bone-black,  by 
which  it  is  decolorized  and  at  the  same  time  freed  from  various  soluble 
impurities.  Concentration  is  then  effected  in  the  vacuum-pan  at  a  tem- 
perature of  about  140°  F.  until  it  has  a  gravity  of  from  28°  to  30° 
Baume,  when  it  is  called  "heavy  liquor."  A  second  bag  or  filter-press 
filtration  is  now  resorted  to  in  many  factories  to  remove  the  sulphate 
of  lime,  which  separates  out  at  this  degree  of  concentration.  It  is  then 
filtered  a  second  time  through  bone-black  to  secure  complete  decoloriza- 
tion  and  purification.  The  final  concentration  is  effected  by  boiling  the 
liquor  in  the  vacuum-pan  until  it  reaches  40°  to  42°  Baume.  That 
product  in  which  the  conversion  has  been  least  complete  remains  liquid, 
and  is  called  "glucose  "  in  the  trade;  that  which  is  ready  to  solidify  is 
known  as  "grape-sugar."  Dr.  Arno  Behr  has  patented  a  process  for 
obtaining  the  solid  grape-sugar  in  pure  crystals.  While  it  is  still  liquid 
there  is  added  to  it  a  small  quantity  of  crystallized  anhydrous  dextrose. 
The  mixture  is  filled  into  moulds,  and  in  about  three  days  it  is  found 
to  be  a  solid  mass  of  crystals  of  anhydrous  dextrose.  The  blocks  are 
then  placed  in  a  centrifugal  machine  to  throw  out  the  still  liquid  syrup, 
and  the  anhydrous  dextrose  remains  as  a  crystalline  mass. 

3.  MANUFACTURE   OF   LEVULOSE. — From    invert   sugar    (mixture   of 
equal  molecules  of  dextrose  and  levulose)  levulose  is  now  obtained  as  a 
commercial  product  by  taking  advantage  of  the  insolubility  of  its  cal- 
cium compound.     According  to  Schering's  patent  inverted  molasses  is 
used,  which  has  been  inverted  with  the  aid  of  hydrochloric  acid.    After 
the  inversion  is  completed  the  solution  is  diluted  to  one-sixth  strength 
with  water,  cooled  to  0°  C.,  and  the  levulose  precipitated  as  the  insoluble 
calcium  levulosate.    The  precipitate  is  separated,  washed  with  ice  water, 
drained  or  centrifugated  thoroughly  and  decomposed  at  a  temperature 
not  exceeding  50°  with  carbon  dioxide  under  pressure.     By  centrifu- 
gating  the  lime  precipitate,  a  syrup  of  thirty  per  cent,  levulose  strength 
is  obtained.     This  is  then  acidified  with  a  weak  acid  and  further  con- 
centrated. 

This  manufactured  levulose  is  used  extensively  in  the  manufacture 
of  confectionery,  as  it  prevents  the  crystallizing  of  the  cane-sugar  used 
and  so  prevents  the  gradual  change  of  clear  transparent  sugar  products 
to  the  opaque  condition.  It  is  also  used  in  the  manufacture  of  marma- 
lades, jellies,  and  sugared  fruits,  for  the  treatment  of  wines,  particularly 
sweet  wines  and  champagnes.  It  is  also  used  in  medicine  in  the  case  of 
diabetes,  where  ordinary  sugar  is  forbidden  to  be  used  in  sweetening 
foods,  and  as  the  basis  of  infant  foods. 

4.  MANUFACTURE  OF  MALTOSE. — By  the  action  of  the  diastase  of  malt 
upon  starch  is  formed  mainly  maltose.     Dilute  sulphuric  acid  will  con- 
vert this  by  prolonged  boiling  into  dextrose,  but  diastase  alone  will  not 
so  convert  it.    The  manufacture  of  maltose  on  a  large  scale  as  a  prepara- 
tion for  use  in  beer-brewing  to  simplify  the  preparation  of  a  suitable 
wort  has  been  attempted  by  several.    Dubrunfaut'and  Cuisinier  patented 
a  process  in  1883  for  preparing  maltose,  either  as  syrup  or  crystallized, 
by  the  following  procedure:    One  part  of  green  or  partially  dried  malt 


PROCESSES  OF  MANUFACTURE.  193 

is  warmed  with  two  to  three  parts  of  water,  digested  for  several  hours 
at  30°  C.,  and  afterwards  filter-pressed  to  obtain  an  "infusion  "  of  malt. 
One  part  of  starch-flour  is  then  suspended  in  two  to  twelve  parts  of  water, 
and  five  to  ten  per  cent,  of  infusion  added,  the  whole  gradually  warmed 
to  80°  C.,  then  heated  under  a  pressure  of  one  and  a  half  atmospheres 
for  thirty  minutes,  quickly  cooled  to  48°  C.,  and  treated  with  five  to 
twenty  per  cent,  of  infusion  and  hydrochloric  acid  (from  six  to  twenty- 
five  cubic  centimetres  of  acid  per  one  hundred  litres).  After  one  hour 
the  mass  is  filtered  through  filter-paper  fastened  upon  linen  cloth. 
The  solution  is  allowed  to  stand  at  48°  C.  for  twelve  to  fifteen  hours, 
then  concentrated  to  28°  B.,  filtered,  again  concentrated  to  38°  B.,  fil- 
tered through  animal  charcoal,  and  allowed  to  crystallize.  A  sample  of 
the  syrup  made  from  corn-starch  by  the  Brussels  Maltose  Company 
working  under  this  patent  was  analyzed  by  Marcker,*  and  found  to  con- 
tain 19.8  per  cent,  water,  78.7  per  cent,  maltose,  1.5  per  cent,  non-sugar, 
and  no  dextrine.  The  process  is,  however,  said  to  have  failed  as  yet  of 
commercial  success.  Saare,f  who  has  recently  investigated  it,  shows  that 
the  complete  conversion  into  maltose  only  takes  place  with  weak  mashes, 
and  he  concludes  from  his  results  that  the  process  is  not  suitable  for 
German  distilleries  under  the  present  conditions.  0 'Sullivan  and  Val- 
entinj  have  also  patented  a  process  for  producing  from  starch,  or  starch- 
yielding  substances,  preferably  from  rice,  a  compound  solid  body,  which 
the  inventors  term  "dextrine-maltose,"  consisting  of  the  same  propor- 
tional quantities  of  dextrine  and  maltose  as  are  ordinarily  obtained  from 
malt  by  a  properly-conducted  mashing  process,  and  which  it  is  intended 
should  replace  a  portion  of  the  malt  used  in  brewing.  For  details,  see 
original  article.  Perfectly  pure  maltose  can  be  obtained  by  Herzf eld's 
process  of  repeatedly  extracting  with  alcohol  from  the  syrupy  product 
of  the  action  of  malt  upon  starch.  The  alcohol  precipitates  the  dextrine, 
but  dissolves  the  maltose,  which  can  then  be  obtained  in  crystalline  con- 
dition. 

5.  SOLUBLE  STARCH. — In  recent  years  considerable  attention  has  been 
given  to  preparing  products  that  will  either  gelatinize  in  the  cold  and 
yield  solutions  with  cementitious  value  or  dissolve  completely  in  hot 
water.  The  starch  under  the  influence  of  acids,  alkalies  or  of  different 
oxidizing  agents  will  be  changed  in  substance  without  the  starch  granules 
losing  their  outward  appearance. 

Soluble  starch  is  widely  utilized  as  a  substitute  for  dextrin,  casein, 
gelatin,  gums  and  glue,  and  specially  as  a  basis  of  sizing  preparations. 

One  of  the  earlier  methods  was  to  heat  starch  dried  at  80°-90°  with 
glacial  acetic  acid.  The  product  of  this  treatment  can  be  washed  with 
cold  water  without  loss  and  is  soluble  in  boiling  water  without  gela- 
tinizing. 

Volatile  organic  acids,  like  formic  and  acetic  acids,  are  advantage- 
ously used,  as  they  can  be  distilled  off  after  the  reaction  and  no  neu- 

*  Jahresber.  der  Chem.  Tech.,   1886,   p.  613. 
t  Dingier,  Polytech.  Journ.,  266,  p.  418. 
t  Journ.  Soc.  Chem.  Ind.,  1888,  p.  446. 
13 


194  STARCH  AND  ITS  ALTERATION  PRODUCTS. 

tralization  of  the  acid  is  required.  One  per  cent,  of  such  acid  acting 
for  five  to  six  hours  at  115°  C.  suffices  to  effect  the  change. 

Starch  so  prepared  with  acid  is  uniformly  soluble  in  hot  water,  while 
soluble  starch  prepared  with  alkalies  gelatinizes  with  cold  water.  To 
avoid  the  production  of  the  alkali  salts  remaining  in  the  product,  am- 
monia has  been  used.  The  starch  is  treated  with  water  containing  two 
per  cent,  of  ammonia  and  the  product  is  dried  in  thin  layers  to  volatilize 
the  ammonia.  The  soluble  starch  so  obtained  forms  a  voluminous  powder 
gelatinizing  with  cold  water. 

Chlorine,  persulphates,  and  perborates  have  also  been  used. 

6.  MANUFACTURE  OF  DEXTRINE. — This  may  be  effected  by  acting  upon 
starch  with  heat  alone,  by  the  action  of  dilute  acids  and  heat,  or  by  the 
action  of  diastase.     The  first  and  second  of  these  methods  are  followed 
in  preparing  the  solid  product.     In  the  manufacture  by  heat  alone  the 
limits  of  temperature  are  212°  to  250°  0.,  although  Pay  en  says  that  200 u 
to  210°  C.  produces  the  most  perfectly  soluble  dextrine.     The  starch  is 
heated  in  revolving  drums,  which  are  frequently  double- jacketed,  and 
contain  oil  in  the  outer  space  in  order  to  insure  uniform  heating.    After 
the  moisture  is  given  off,  the  loss  of  weight  in  roasting  is  small,  two 
hundred  and  twenty  pounds  of  starch  giving  one  hundred  and  seventy- 
six  pounds  of  finished  dextrine. 

In  the  manufacture  by  the  aid  of  acids  the  starch  is  mixed  with  dilute 
nitric  or  hydrochloric  acid  so  as  to  form  a  damp  powder.  This  is  exposed 
to  a  temperature  of  100°  to  120°  C.  until  the  transformation  is  complete, 
which  can  be  determined  by  applying  the  iodine  test  from  time  to  time. 
The  process  must  be  arrested  promptly  when  the  starch  is  all  changed, 
or  the  dextrine  will  pass  rapidly  into  glucose.  Oxalic  acid  is  also  some- 
times employed  in  the  manufacture  of  dextrine. 

7.  MANUFACTURE  OF  SUGAR-COLORING  (Caramel,  or  Zucker-couleur). — 
Very  considerable  quantities  of  an  artificial  coloring  material  for  use  in 
coloring  beer,  rum,  cognac,  and  high  wines  are  made  on  the  Continent  of 
Europe  from  starch.    For  the  manufacture  of  rum  and  cognac  coloring, 
starch  is  treated  with  dilute  sulphuric  acid,  as  before  described  for  the 
manufacture  of  dextrose  and  dextrine  mixtures,  but  the  heating  is  con- 
tinued until  all  the  dextrine  has  been  changed  into  dextrose,  as  deter- 
mined by  taking  a  sample  from  time  to  time  and  testing  it  with  an  excess 
of  ninety-six  per  cent,  alcohol.     When  no  longer  any  turbidity  from 
separated  dextrine  shows,  the  reaction  is  considered  as  finished.     The 
sulphuric  acid  is  then  neutralized  with  carbonate  of  lime,   and  after 
sufficient  standing  the  clear  liquor  is  run  off  from  the  precipitated  sul- 
phate of  lime.    It  is  now  concentrated  to  36°  B.  and  filtered.     The  hot 
filtrate  is  then  run  into  a  vessel  provided  with  mechanical  agitation  and 
heated  to  boiling,  when  crystallized  soda  salt   (three  kilos,  of  soda  to 
one  hundred  kilos,  of  sugar  solution)    is  added  in  small  portions  at 
a  time.     The  contents  of  the  kettle  froth  and  must  be  continuously 
stirred.     White  and   inflammable  vapors  are  grven  off  and  the  color 
rapidly  deepens.     The  heat  is  now  gradually  lessened  to  prevent  car- 
bonizing of  the  contents  of  the  vessel,  and  the  color  is  tested.     A  drop 
chilled  by  being  dropped  into  water  should  harden  and  be  brittle  and 


PRODUCTS. 


195 


should  taste  bitter.  The  contents  of  the  kettle  are  then  cooled  some- 
what by  adding  hot  water.  When  the  production  of  the  color  is  com- 
pleted, the  contents  of  the  kettle  are  extracted  with  water,  filtered  to 
remove  carbonized  particles,  and  then  tested  as  to  quality.  The  coloring 
is  made  in  several  grades  or  depths  of  color,  which  are  also  differently 
soluble,  the  one  in  seventy-five  per  cent,  alcohol  and  the  other  in  eighty 
per  cent,  alcohol.  For  beer-  or  wine-coloring  it  is  not  necessary  to  be  so 
careful  to  use  a  glucose  freed  perfectly  from  dextrine,  and,  instead  of 
soda,  ammonium  carbonate  is  taken.  The  product  is  soluble  in  water, 
but  not  so  readily  in  alcohol. 

m.  Products. 

1.  STARCH. — The  properties  and  action  of  reagents  upon  starch  have 
already  been  noted  in  speaking  of  it  as  a  raw  material.  It  is  only  neces- 
sary to  subjoin  a  few  analyses  of  commercial  starches  in  order  to  show 
the  character  of  that  usually  obtainable.  Those  of  potato  and  wheat 
starch  are  by  J.  Wolff,  as  quoted  in  "Wagner's  Chemical  Technology," 
and  those  of  corn  starch  are  by  Dr.  Archbold,  as  given  by  him  in  the 
"Journal  of  the  Society  of  Chemical  Industry,"  1887,  p.  188. 


PERCENTAGE  COMPOSI- 
TION. 

Potato 
starch. 
(Wolff.) 

Wheat 
starch,  I. 
(Wolff.) 

Wheat 
starch,  II. 
(Wolff.) 

Corn 

starch,  I. 
(Archbold.) 

Corn 
starch,  II. 
(Archbold.) 

Corn 
starch.  III. 
(Archbold.) 

Starch  

83.59 

83.91 

79.63 

98.50 

92.88 

90.33 

Gluten  

0.10 

1.84 

Cellulose  
Ash      

0.50 
053 

1.44 
003 

3.77 
065 

030 

|     2.38 
0.60 

|     4.25 
0.65 

"Water  

15.38 

14.52 

14.20 

1.20 

4.14 

4.77 

Total    

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

2.  GLUCOSE  AND  GRAPE-SUGAR. — Starch-sugar  appears  in  commerce 
in  a  great  variety  of  grades  and  under  a  similar  variety  of  names.  As 
already  said,  in  the  United  States  the  name  glucose  is  in  general  applied 
to  the  liquid  products,  while  that  of  grape-sugar  is  given  to  the  solid 
products.  In  France,  w-here  large  quantities  of  similar  products  are 
manufactured,  the  liquid  product  is  known  as  "sirop  cristal  "  and  the 
solid  product  "glucose  masse."  The  following  analyses  show  the  com- 
position of  the  commercial  products  as  now  manufactured  by  the  Corn 
Products  Co.* 


Corn 
syrup. 

70  sugar. 

80  sugar. 

Anhydrous 
sugar. 

Water  

per  cent. 
190 

per  cent. 
197 

per  cent. 
11  2 

per  cent. 
4.0 

Dextrose  ... 

385 

702 

799 

94.6 

Dextrine  

420 

93 

80 

0.7 

Ash    

05 

08 

0.9 

0.7 

Journ.  Soc.  Chem.  Ind.,  1909,  p.  347. 


196 


STARCH  AND  ITS  ALTERATION  PRODUCTS. 


3.  MALTOSE. — Maltose  forms  fine  white  crystalline  needles  aggregating 
in  warty  groups,  which  have  a  faint  sweetish  taste.    It  is  soluble  in  water 
and  methyl  and  ethyl  alcohol,  but  more  difficultly  in  the  last  than  dex- 
trose.   Its  formula  is  C12H22011,  and  it  crystallizes  with  one  molecule  of 
water,  which  it  loses  slowly  at  100°  C.  in  a  vacuum.    Its  specific  rotatory 
power  is,  according  to  Meissl,   (S)d  =  140.375  --  .01837  P  --  .095  T, 
where  P  equals  the  percentage  strength  of  the  solution  and  T  the  tem- 
perature.    A  ten  per  cent,  solution  at  20°   C.  would  then  be  138.3°. 
0 'Sullivan  takes  it  as  139.2°  for  a  ten  per  cent,  solution.     Its  reducing 
power  with  Fehling's  solution  is  frequently  stated  to  be  two-thirds  that 
of  dextrose,  but  Brown  and  Heron  as  well  as  0 'Sullivan  make  it  more 
exactly  sixty-two  per  cent,  of  that  sKown  by  dextrose.    It  has  no  action, 
however,  upon  Barfoed's  reagent  (see  p.  200),  which  is  reduced  by  dex- 
trose.   Maltose  is  said  to  be  directly  and  completely  fermentable  without 
previous  change  into  dextrose,  but  more  slowly  than  this  latter,  so  that 
if  a  mixture  of  maltose  and  dextrose  be  fermented  with  yeast,  the  whole 
of  the  dextrose  disappears  before  the  former  sugar  is  acted  upon. 

4.  DEXTRINE. — Pure  dextrine  is  a  white  amorphous  solid.    It  is  taste- 
less, odorless,  and  non-volatile.     It  is  completely  soluble  in  cold  water, 
but  the  commercial  varieties  usually  leave  from  twelve  to  twenty  per 
cent,  or  even  more  of  starch  and  other  insoluble  residue  when  dissolved. 
Heated  with  dilute  acids  it  yields  maltose  and  ultimately  dextrose.    It  is 
unf ermentable  if  free  from  sugar.    It  has  no  reducing  power  on  Fehling  's 
solution.     Probably  what  is  called  dextrine  is  a  mixture  of  products 
obtained  in  the  breaking  down  of  the  complex  starch-molecules.     Some 
investigators  claim  to  have  obtained  sixteen  distinct  modifications  or 
varieties  of  dextrine  in  this  way.    We  have  before  (see  p.  187)  alluded 
to   amylodextrine,   erythrodextrine,   achroodextrine,   and  maltodextrine. 

Commercial  dextrine,  or  "British  gum,"  gives  a  brown  coloration 
with  iodine,  and  probably  consists  largely  of  erythrodextrine.  The  fol- 
lowing analyses  by  R.  Forster  give  an  idea  of  the  composition  of  the  dex- 
trines  usually  obtainable : 


PERCENTAGE  COMPOSITION. 

First 
quality 
dextrose. 

Dark- 
burned 
starch. 

Brown 
dextrine. 

Gommel- 
ine. 

Old 
dextrine. 

Lightr 
burned 
starch. 

72.45 

70.43 

63.60 

59.71 

49.78 

5.34 

Su°"ar    

8.77 

1.92 

7.67 

5.76 

1.42 

0.24 

Insoluble  

13.14 

19  97 

14.51 

20.64 

30.80 

86-47 

"Water  

5.64 

7  68 

14  22 

13.89 

18.00 

7.95 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

Dextrine  is  used  as  a  substitute  for  natural  gums,  especially  for  gum 
arabic.  It  is  thus  used  in  calico-printing  and  in  the  mordanting  and 
printing  of  colors  upon  most  other  classes  of  textile  goods,  for  mucilage, 
for  glazing  cards  and  paper,  as  warp-dressing,  arid  in  the  manufacture 
of  beer.  It  forms  the  crust  on  bread  by  the  change  of  the  starch  of  the 
flour  in  baking,  and  is  present  in  most  products  from  starch  or  starch- 
sugar. 


ANALYTICAL  TESTS  AND  METHODS.  197 

5.  UNFERMENTABLE  CARBOHYDRATES  (Gallisin}. — The  presence  of  an 
unfermentable  carbohydrate  in  starch-sugar  was  long  since  pointed  out 
by  0  'Sullivan.  The  compound  which  has  been  specially  studied  is  known 
as  gallisin,  and  is  prepared  by  fermenting  a  twenty  per  cent,  solution  of 
starch-sugar  with  yeast  at  18°  or  20°  C.  for  five  or  six  days.  The 
resultant  liquid  was  filtered,  evaporated  to  a  syrup  at  100°  C.,  and  shaken 
with  a  large  excess  of  absolute  alcohol.  The  treatment  with  alcohol  was 
repeated  several  times  until  the  unaltered  sugar  and  other  impurities 
were  removed,  the  syrup  being  converted  into  a  yellowish  crumbling 
mess,  which,  by  pounding  in  a  mortar  with  a  mixture  of  equal  parts  of 
alcohol  and  ether,  was  obtained  as  a  gray  powder.  After  purifying  with 
animal  charcoal  and  drying  over  sulphuric  acid,  the  gallisin  was  obtained 
as  a  white  amorphous  extremely  hygroscopic  powder.  Its  taste  is  at  first 
sweet,  but  afterwards  becomes  insipid.  It  is  easily  decomposable  by  heat, 
even  at  100°  C.  It  is  readily  soluble  in  water,  nearly  insoluble  in  abso- 
lute alcohol,  and  but  slighly  more  soluble  in  methy  alcohol,  in  which 
respect  it  differs  from  dextrose.  Gallisin  is  stated  to  have  the  composi- 
tion C12H24010.  Its  concentrated  aqueous  solution  is  distinctly  acid  to 
litmus  and  a  sparingly  soluble  barium  compound  may  be  obtained  there- 
from by  adding  alcoholic  baryta.  It  reduces  nitrate  of  silver  on  heating, 
especially  on  addition  of  ammonia,  reduces  bichromate  and  perman- 
ganate, and  precipitates  hot  Fehling's  solution.  Its  cupric  oxide  reduc- 
ing power  (dextrose  —  100)  is  stated  to  be  45.6°.  Gallisin  is  dextro- 
rotatory, the  value  for  Sd  being  stated  to  be  80.1°  in  twenty-seven  per 
cent.,  82.3°  in  ten  per  cent.,  and  84.9°  in  1.6  per  cent,  solutions.  By 
heating  with  dilute  sulphuric  acid  for  some  hours  gallisin  yields  a  large 
proportion  of  dextrose,  but  its  complete  conversion  has  not  so  far  been 
effected. 

It  is  doubtful  whether  "gallisin  "  as  hitherto  obtained  is  really  a 
definite  compound,  but  the  possibility  of  isolating  a  reducing  or  optically 
active  body  from  the  liquid  left  after  fermenting  solutions  of  many  speci- 
mens of  sugar-starch  cannot  be  ignored  in  considering  the  composition 
of  commercial  glucose. 


IV.  Analytical  Tests  and  Methods. 

1.  FOR  STARCH. — The  usual  method  for  the  determination  of  starch 
is  to  invert  by  the  action  of  dilute  acid,  and  then  determine  the  dextrose 
produced  by  the  aid  of  Fehling's  solution.  In  this  case  one  hundred 
parts  of  dextrose  are  taken  as  indicating  ninety  of  starch.  It  has  been 
found,  however,  that  the  change  to  dextrose  by  the  aid  of  dilute  sulphuric 
acid  is  not  complete,  that  other  non-reducing  bodies  are  formed,  and 
that  but  ninety-five  per  cent,  of  the  starch  is  converted  into  dextrose. 
The  hydrolysis  is  more  completely  effected  by  the  aid  of  hydrochloric 
acid,  as  carried  out  in  Sachsse's  method.  2.5  to  3  grammes  of  dry  starch 
(or  so  much  of  the  starch-containing  substance  as  would  correspond  to 
this  amount  of  starch)  are  placed  in  a  flask  with  two  hundred  cubic 
centimetres  of  water  and  twenty  cubic  centimetres  of  hydrochloric  acid 


198 


STARCH  AND  ITS  ALTERATION  PRODUCTS. 


FIG.  56. 


and  heated  on  the  water-bath  with  inverted  condenser  for  three  hours. 
(Marcker  states  that  heating  for  three  hours  with  this  amount  of  hydro- 
chloric acid  does  not  give  more  than  ninety-six  to  ninety-seven  per  cent, 
of  the  starch  as  sugar,  as  some  of  the  latter  is  destroyed.  He  recom- 
mends using  fifteen  cubic  centimetres  of  acid  and  heating  for  two  hours.) 
The  contents  of  the  flask  are  then  nearly  neutralized  with  sodium  hy- 
droxide, filled  to  the  mark,  and  the  dextrose  determined  by  Fehling's 
solution.  If  other  carbohydrates  or  cellulose  are  present,  which  would 
be  also  converted  into  dextrose  by  hydrochloric  acid,  the  starch  must  be 
previously  brought  into  the  soluble  form,  which  may  be  done  by  heating 

with  water  to  130°  C.  in  a  pressure- 
flask  like  that  of  Lintner,  shown  in 
Fig.  56.  Or  the  starch  may  be  hy- 
drolyzed  in  part  by  infusion  of  malt 
or  diastase  at  62.5°  C.,  filtered  from 
cellulose,  etc.,  and  then  treated  with 
hydrochloric  acid  for  complete  hy- 
drolysis as  above.  In  this  latter  case, 
the  process  of  Reinke*  is  the 
simplest.  Three  grammes  of  the 
sample  as  finely  powdered  as  pos- 
sible are  heated  to  boiling  with  fifty 
cubic  centimetres  of  water,  cooled 
at  62.5°  C.,  and  hydrolyzed  for  an 
hour  at  this  temperature  with  .05 
gramme  of  diastase.  This  is  pre- 
pared according  to  Lintner's  pro- 
cedure, by  making  an  alcoholic 
twenty  per  cent,  extract  (1:3)  of 
raw  malt,  adding  to  the  filtrate  two 
volumes  of  ninety-six  per  cent,  alco- 
hol, separation  of  the  precipitated 

diastase,  washing  with  alcohol  and  ether,  and  drying  in  a  desiccator.  The 
mixture  is  then  cooled,  diluted  with  water  to  two  hundred  and  fifty  cubic 
centimetres,  and  filtered.  Of  the  filtrate,  two  hundred  cubic  centimetres 
are  taken  and  hydrolyzed,  as  before  described,  with  fifteen  cubic  centi- 
metres of  hydrochloric  acid  of  1.125  specific  gravity  for  two  and  a  half 
hours,  when  the  solution  is  neutralized  and  the  dextrose  determined. 

A  more  elaborate  course  of  treatment,  following  in  the  main  the  same 
lines  as  the  procedure  of  Reinke  just  described,  but  stopping  with  the 
action  of  the  diastase,  has  been  published  by  O 'Sullivan,  and  is  given  at 
length  by  Allen,  f  In  this  case  the  filtered  liquid,  assumed  to  contain 
nothing  but  maltose  and  dextrine,  is  made  up  to  one  hundred  cubic 
centimetres,  and  the  density  determined.  It  is  then  tested  with  Fehling's 
solution  for  the  maltose,  and  the  dextrine  deduced  from  the  rotatory 
power  of  the  solution.  The  maltose  found,  divided  by  1.055,  gives  the 


•Jahresber.  Chem.  Technol.,   1887,  p.  863. 

t  Commercial  Organic  Analysis,  3d  ed.,  vol.  i,  p.  415. 


ANALYTICAL  TESTS  AND  METHODS.  199 

corresponding  weight  of  starch,  which,  added  to  the  dextrine  found, 
gives  the  total  number  of  grammes  of  starch  represented  by  one  hundred 
cubic  centimetres  of  the  solution. 

The  method  for  the  determination  of  starch  in  cereals  most  generally 
used  in  Germany  at  present  is  that  of  Marcker.*  Three  grammes  of  sub- 
stance are  placed  in  a  small  beaker  (preferably  of  metal),  which  is  placed 
as  one  of  several  in  a  Soxhlet  pressure-boiler,  or  the  test  is  carried  out 
in  the  Lintner  pressure-flask,  figured  on  the  preceding  page,  and  heated 
to  the  temperature  of  boiling  water.  It  is  then  cooled  to  60°  to  65°  C., 
five  cubic  centimetres  of  thin  malt  infusion  are  added,  and  it  is  digested 
at  this  temperature  for  some  twenty  minutes.  It  is  then  made  faintly 
acid  (one  cubic  centimetre  of  tartaric  acid  suffices)  and  heated  under  a 
pressure  of  three  to  four  atmospheres.  It  is  then  cooled  down  and  an 
additional  five  cubic  centimetres  of  malt  infusion  added,  with  which  it  is 
digested  an  half-hour.  The  solution  is  then  brought  up  to  one  hundred 
cubic  centimetres,  filtered,  and  determined  with  Fehling's  solution,  either 
by  titration  or  by  weighing  the  reduced  copper. 

Of  other  methods  proposed  for  starch  determinations  it  is  only  neces- 
sary to  notice  the  Asboth  method,  proposed  in  1887.  It  depends  on  the 
fact  that  starch  forms  a  compound  with  baryta-water,  C24H40020BaO, 
containing  19.1  per  cent,  of  BaO,  which  is  insoluble  in  forty-five  per 
cent,  alcohol.  The  baryta-water  is  used  in  excess,  and  the  free  alkaline 
earth  determined  by  titration  with  decinormal  hydrochloric  acid.  Nu- 
merous experimenters  have  taken  exception  to  the  method  that  the  results 
were  variable,  and  that  starch  combined  with  varying  amounts  of  barium 
oxide.  To  these  objections  the  author  made  a  reply  later,  f  and  claims 
that  the  presence  of  fat  in  the  cereals  interferes  with  the  accuracy  of  the 
determination,  and  that  if  the  fat  be  previously  extracted  by  ether,  the 
determinations  in  the  fat-free  residue  are  accurate  and  concordant.  J. 
Napier  Spence,  in  the  "Journal  of  the  Society  of  Chemical  Industry," 
for  1888,  p.  77,  has  also  come  to  the  defence  of  the  Asboth  method  and 
shown  the  conditions  under  which  it  yields  accurate  results. 

2.  GLUCOSE,  OR  DEXTROSE. — For  the  determination  of  dextrose  alone 
the  Fehling's  solution  affords  the  most  accurate  means.    For  its  use,  see 
analysis  of  raw  sugars,  p.  174.     In  the  absence  of  any  other  optically 
active  body  its  examination  with  the  polariscope  will  also  suffice.     For 
mixtures  like  commercial  glucose,  which  contains  dextrose,  maltose,  and 
dextrine,  see  later. 

3.  MALTOSE. — This  variety  of  sugar,   as  before  stated,  has  optical 
activity  and  reducing  power  on  Fehling's  solution.    It  can,  however,  be 
distinguished  from  dextrose  by  its  failure  to  reduce  Barfoed's  solution, 
which  is  reduced  by  dextrose  and  invert  sugar.    This  reagent  is  made  by 
dissolving  one  part  of  neutral  copper  acetate  in  fifteen  parts  of  water,  to 
two  hundred  cubic  centimetres  of  which  five  cubic  centimetres  of  thirty- 
eight  per  cent,  acetic  acid  is  added.     Boiled  for  several  minutes  with 
maltose  solution  it  shows  no  reduction. 

*Jahresber.   Chem.   Technol.,    1885,   p.   863. 
f  Chemiker  Zeitung,  1889,  pp.  591  and  611. 


200  STARCH  AND  ITS  ALTERATION  PRODUCTS. 

4.  DEXTRINE.  —  Pure  dextrine  differs  from  dextrose  and  maltose  in 
showing   no   reducing   power   with   either   Fehling's    solution    or   with 
Knapp  's  mercuric  cyanide  solution.    It  can,  indeed,  be  freed  from  admix- 
ture with  dextrose  and  maltose  by  heating  with  an  excess  of  an  alkaline 
solution  of  mercuric  cyanide,  which  oxidizes  these  two  varieties  of  sugar, 
leaving  the  dextrine  unaffected.     (See  Wiley's  method  below.) 

5.  COMMERCIAL    GLUCOSE    AND    SIMILAR    MIXTURES    DERIVED    FROM 
STARCH.  —  As  commercial  glucose  is  likely  to  be  a  mixture  of  the  three 
compounds,  dextrose,  maltose,  and  dextrine,  its  analysis  and  the  deter- 
mination  of  the   several    constituents   becomes    a   frequently-recurring 
problem.     Three  methods  have  been  proposed.     The  first,  by  Allen,* 
requires  the  determination  of  moisture  and  ash  in  the  sample,  which, 
subtracted  from  100,  leaves  the  total  organic  solids,  0.     The  apparent 
specific  rotatory  power,  8,  and  the  cupric  oxide  reducing  power  (in  terms 
of  dextrose  reduction  =  100),  K,  are  now  determined.     Then,  if  m  be 
the  maltose,  g  the  dextrose-glucose,  and  d  the  dextrine,   Allen  deter- 
mines  the   respective    percentages    by   the    use    of   the    formulas    m  — 


The  author  states  that  the  presence  of  gallisin  or  other  unfermentable 
sugar  may  vitiate  the  values  of  K  and  8,  as  observed,  and  so  make  the 
results  inaccurate. 

The  second  method  is  that  of  Wiley,  f  which  is  based  upon  the  theory 
that  boiling  with  an  alkaline  solution  of  mercuric  cyanide  will  destroy 
the  optical  activity  of  maltose  and  dextrose,  leaving  that  of  dextrine 
unchanged.  The  cupric  oxide  reducing  power  of  the  sample  is  ascer- 
tained in  the  usual  way  by  Fehling's  solution.  The  specific  rotatory 
power  is  determined  by  polarizing  a  ten  per  cent,  solution  (previously 
heated  to  boiling)  in  the  ordinary  manner.  Ten  cubic  centimetres  of 
this  solution  used  for  polarizing  are  then  treated  with  an  excess  of  an 
alkaline  solution  of  mercuric  cyanide,  and  the  mixture  boiled  for  two 
to  three  minutes.  It  is  then  cooled  and  slightly  acidulated  with  hydro- 
chloric acid,  which  destroys  the  reddish-brown  color  possessed  by  the 
alkaline  liquid.  The  solution  is  then  diluted  to  fifty  cubic  centimetres, 
and  the  rotation  observed  in  a  tube  four  decimetres  in  length. 
The  angular  rotation  observed  will  be  due  simply  to  the  dextrine, 
the  percentage  of  which  may  then  be  calculated  by  the  formula 

rotation  X  1000  X  cubic  centimetres  of  solution  polarized 

-  __  _  _  _  —  Der- 
198  X  length  of  tube  in  centimetres  X  weight  of  the  sample  taken 

centage  of  dextrine.  The  percentages  of  dextrose  and  maltose  may  be 
deduced  from  the  reducing  power  of  the  sample,  or  from  the  difference  in 
specific  rotatory  power  before  (8)  and  after  (s)  the  treatment  with  alka- 
line mercuric  cyanide.  Thus,  K  =  1.00  g  +  .62m,S  =  .527  g  -+-  139.2  m 

-f-  1.98  d  and  s  =  1.98  d,  whence  m  =-  ,  -  .    g  can  now  be 

1.UOUAU 

found  from  the  first  of  the  three  equations,  and  then  d  in  the  second. 

*  Commercial  Organic  Analysis,  3d  ed.,  vol.  i,  p.  365.     f  Chemical  News,  xlvi,  p.  175. 


BIBLIOGRAPHY  AND  STATISTICS.  201 

Wiley's  process  was  employed  by  the  Committee  of  the  National 
Academy  of  Science  in  their  investigation  of  commercial  glucose  from 
corn  starch.  It  is,  however,  based  upon  several  assumptions  that  have 
not  been  specifically  proven,  and  especially  in  the  presence  of  any  con- 
siderable quantity  of  "maltose  are  its  results  open  to  doubt.  (See  Allen, 
''Commercial  Organic  Analysis,"  3d  ed.,  vol.  i,  p.  369,  foot-note.) 

The  third  method  of  estimating  the  constituents  in  commercial  glu- 
cose is  due  to  C.  Graham,  and  is  probably  more  exact  than  either  of 
those  before  mentioned.  Dissolve  five  grammes  of  the  sample  in  a  small 
quantity  of  hot  water  and  add  the  solution  drop  by  drop  to  one  litre 
of  nearly  absolute  alcohol.  Dextrine  is  precipitated,  and  on  standing 
becomes  attached  to  the  sides  of  the  beaker,  while  maltose,  gallisin,  and 
dextrose  are  soluble  in  the  large  quantity  of  alcohol  employed.  If  the 
solution  be  then  decanted  from  the  precipitate,  the  dextrine  in  the  latter 
can  be  ascertained  by  drying  and  weighing,  or  by  dissolving  it  in  a 
definite  quantity  of  water  and  observing  the  solution,  density,  and  rota- 
tion. The  alcohol  is  distilled  off  from  the  solution  of  the  sugars  and  the 
residual  liquid  divided  into  aliquot  portions,  in  one  of  which  the  gallisin 
may  be  determined  after  fermentation  with  yeast,  while  others  are 
employed  for  the  observation  of  the  specific  rotation  and  reducing 
power,  which  data  give  the  means  of  calculating  the  proportions  of  mal- 
tose and  dextrose  in  the  sample. 


V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

1879. — Die  Starkefabrikation,  F.  Stohmann,  Berlin. 

1881. — Starch,  Glucose,  and  Dextrine,  Frankel  and  Hutter,  Philadelphia. 
1882. — Die  Starke-  und  die  Mahlproducte,  F.  von  Hohnel,  Berlin. 
1884. — Report  on  Glucose  by  the  National  Academy  of  Sciences,  Washington. 
1886. — Die  Starkefabrikation,  Dextrin  und  Traubenzucker,  L.  von  Wagner,  2te  Auf., 
Braunschweig. 

Fabrication  de  PAmidon,  E.  Guillaume,  Paris. 
1887. — Die  Fabrikation  der  Stlirke,  K.  Birnbaum,  Braunschweig. 
1888. — Handbuch  der  Kohlenhydrate,  B.  Tollens,  Breslau. 
1890. — Manual  of  Sugar  Analysis,  J.  H.  Tucker,  2d  ed.,  New  York. 

Traite"  d' Analyse  des  Mati&res  sucres,  D.  Siderski,  Paris. 

1891. — Die  Untersuchung  Landwirthschaftlich  wichtiger  Stoffe,  J.  Kb'nig,  Berlin. 
1892. — The  Principal  Starches  used  as  Food,  W.  Griffith,  Cirencester,  England. 
1893. — Introductory  Manual  for  Sugar-Growers,  F.  Watts,  London. 
1894. — Die  Starkefabrikation,  Dr.  B.  von  Posanner,  Wien. 
1895. — Handbuch  der  Kohlenhydrate,  B.  Tollens,  2te  Band,  Breslau. 
1896. — Die  Industrie  der  Stiirke  in  der  Vereinigten  Staaten,  O.  Saare,  Berlin. 
1897. — Die  Fabrikation  der  Kartoffelstiirke,  0.  Saare,  Berlin. 
1900. — Die  Rohstoffe  des  Pflanzenreiches,  J.  Wiesner,  2te  Auf.,  Leipzig. 
1901. — Die  Fabrikation  von  Stiirkezucker,  Dextrine,  etc.,  Joseph  Borsch,  Wien. 
1903. — Foods,  their  Composition  and  Analysis,  A.  W.  Blyth,  5th  ed.,  London. 
1908. — Lehrbuch  der  Stlirkefabrieation,  Parow,  Berlin. 
1909. — Die  Starkefabrikation,  J.  Schmidt,  Hannover. 
1911. — Die  Starkefabrikation,  F.  Rehwald,  4te  Auf.,  A.  Hartleben,  Wien. 


202  STARCH  AND  ITS  ALTERATION  PRODUCTS. 

STATISTICS. 

1.  PRODUCTION  OF  STARCH  IN  THE  UNITED  STATES  AND  GERMANY. — 
O.   Saare  in  1896  gave  the  following  summary  of  the  production  in 
these  chief  producing  countries : 

United  States.  Germany. 

Hundred  kilos.  Hundred  kilos. 

Potato  starch    120,000  —      180,000  2,000,000  —  3,000,000 

Corn  starch 2,000,000  —  3,000,000  25,000  —  50,000 

Wheat  starch    150,000  —     200,000  50,000  —  100,000 

Rice  starch 200,000  —  250,000 

2,270,000  —  3,380,000  2,275,000  —  3,400,000 

2.  PRODUCTION    OF    GRAPE-SUGAR    (STARCH-SUGAR),    GLUCOSE,    DEX- 
TRINE, ETC. — The  same   authority  gives  the  following  figures  for  the 
products  from  starch : 

United  States.  Germany. 

Hundred  kilos.  Hundred  kilos. 

Grape-sugar  and  glucose  syrup . .   2,500,000  —  3,000,000  350,000  —  400,000 

Sugar-color    ( caramel )    30,000  —     40,000 

Dextrine   20,000  —       50,000  150,000  —  180,000 

2,520,000  —  3,050,000         530,000  —  620,000 

3.  PRODUCTION  OF  STARCH  IN  THE  UNITED  STATES  (Census  of  1905) : 

1900.  1905. 

Corn  starch  produced  (Ibs.) 247,051,744  150,520,009 

Value  $6,133,001  $4,702,309 

Potato  starch  produced  (Ibs.)  ..  33,941,826  27,709,400 

Value  $1,129,129  $924,476 

Cassava  and  wheat  starch  (Ibs.)  16,809,569  17,845,121 

Value  $775,835  $1,124,612 

Total  starch  (Ibs.)  297,803,139  196,074,530 

Value    $8,037,965  $6,751,397 

4.  CORN  PRODUCTS. — The  corn  crop  "of  the  United  States  in  1908  is 
said  to  have  been  2,643,000,000  bushels,  valued  at  $1,615,000,000.     Of 
this,  ninety  per  cent,  is  used  as  food  and  ten  per  cent,  is  used  in  the 
industries  and"  for  export. 

Two  per  cent.,  or  50,000,000  bushels,  is  used  in  the  starch  and  glucose 
industry. 

Four  per  cent.,  or  100,000,000  bushels,  is  used  in  the  fermentation 
and  milling  industry. 

Four  per  cent.,  or  100,000,000  bushels,  is  exported. 

(T.  B.  Wagner,  Jour.  Soc.  Chem.  Ind.,  1909,  p.  343.) 

5.  EXPORTATIONS  OF  STARCH,  GLUCOSE,  AND  GRAPE-SUGAR  FROM  THE 
UNITED  STATES. 

1908.  1909.  1910. 

Starch    (Ibs.)    48,125,851  33,228,278  51,535,570 

Value    $1,042,054  $780,155  $1,274,773 

Glucose    (Ibs.)    98,608,192  92,652,409  112,730,639 

Value    $1,898,652  $1,138,405  $2,623,131 

Grape-sugar    (Ibs.)    31,078,642  19,572,095  37,098,449 

Value  ' $641,988  $407,683  $792,089 

(Commerce  and  Navigation  of  the  United  States,  1910.) 


NATURE  AND  VARIETIES  OF  FERMENTATION.  203 


CHAPTER    VI. 

FERMENTATION   INDUSTRIES. 

A.  NATURE  AND  VARIETIES  OF  FERMENTATION. 

UNDER  the  term  fermentation  are  included  certain  methods  of  decom- 
position of  organic  compounds  which  presuppose  the  presence  of  definite 
substances  called  " ferments,"  which  do  not,  however,  apparently  take 
part  in  the  chemical  reactions  but  act  after  the  manner  of  the  inorganic 
catalytic  agents.  Their  presence  in  relatively  small  amount  and  the 
existence  of  conditions  of  temperature,  etc.,  favorable  to  them,  suffice  to 
bring  about  the  decomposition  of  large  quantities  of  the  fermentable 
material. 

The  ferments  which  seem  to  determine  the  decomposition  may  be 
either  soluble  unorganized  ferments  or  insoluble  organized  ferments, 
which  are  minute  vegetable  growths.  The  decompositions  which  are 
brought  about  by  organized  ferments  differ  quite  notably  in  their  results 
from  those  which  can  be  induced  by  mere  chemical  reagents.  Thus,  the 
decomposition  of  sugar  into  alcohol  and  carbon  dioxide,  as  it  is  brought 
about  by  the  activity  of  the  yeast-cell,  cannot  be  brought  about  by  purely 
chemical  treatment.  On  the  other  hand,  the  action  of  the  unorganized 
ferments  is  much  more  analogous  to  that  induced  by  chemical  reagents. 
Thus,  the  hydrolytic  action  of  diastase  on  starch  can  also  be  per- 
fectly imitated  by  treating  with  dilute  acids.  Buchner  has,  however, 
recently  shown  that  the  liquid  expressed  from  fresh  yeast  cells  after 
triturating  them  can  produce  all  the  changes  attributed  to  the  cells 
themselves,  and  that  it  owes  its  activity  to  an  enzyme  called  zymase, 
which  is  produced  by  the  cells. 

With  regard  to  the  chemical  nature  of  the  enzymes,  or  soluble  fer- 
ments, we  only  know  that  they  belong  to  the  class  of  proteids.  A  recent 
analysis  of  diastase  by  Lintner  may  be  taken  as  typical  of  the  class: 
carbon,  46.66  per  cent.;  hydrogen,  7.35  per  cent.;  nitrogen,  10.42  per 
cent. ;  sulphur,  1.12  per  cent. ;  and  oxygen,  34.45  per  cent. 

While  soluble  in  water  and  glycerol  they  are  insoluble  in  alcohol, 
and  are  precipitated  from  aqueous  solutions  on  addition  of  lead  acetate. 
Their  activity  is  destroyed  by  heating,  that  of  diastase  at  75°  C.,  and  all 
by  boiling  with  water.  Their  activity  is  not  destroyed  by  the  presence 
of  antiseptics,  which  arrest  the  action  of  the  organized  ferments.  Thus, 
chloroform,  thymol,  and  salicylic  acid  will  all  arrest  the  activity  of  the 
organized  growth  but  not  interfere  with  that  of  the  soluble  ferments. 
Sodium  fluoride  in  one  per  cent,  solution  is  said  to  check  entirely  the 
growth  of  the  organized  ferments,  but  is  without  action  on  those  which 
are  soluble. 


204  FERMENTATION  INDUSTRIES. 

Foremost  among  the  soluble  ferments  is  diastase.  This  is  the  ferment 
formed  from  the  albuminoids  of  the  cereals  during  the  process  of  ger- 
mination. It  is  especially  developed  in  the  malting  process  as  applied 
to  barley.  Its  chief  function  is  the  saccharification  of  the  starch  of  the 
grain,  changing  it  into  dextrine,  maltose,  and  dextrose. 

The  amount  of  starch  that  a  given  quantity  of  diastase  can  convert 
cannot  be  stated  with  absolute  certainty,  as  it  varies  with  the  conditions 
of  its  preparation,  the  strength  of  the  infusion,  and  other  points.  Its 
progress  vCan,  of  course,  be  controlled  by  the  iodine  reaction,  as  stated 
under  starch.  Commercial  extracts  of  malt  are  infusions  of  malted 
barley,  which  contains  the  products  of  the  inversion  of  the  starch.  The 
solid  extracts  obtained  by  evaporation  of  these  infusions  in  vacuo  at 
low  temperatures  should  be  readily  soluble,  and  should  show  that  they 
still  contain  active  diastatic  ferment  by  being  able  to  convert  their  own 
weight  of  starch  within  a  short  time. 

Invertase. — Invertase  is  capable  of  converting  cane  sugar  or  sucrose 
into  invert  sugar.  This  rather  resistant  enzyme  may  be  readily  ex- 
tracted from  the  yeast  by  various  means.  From  yeast  cells  which  have 
been  killed  with  chloroform  it  may  be  extracted  with  water,  and  is  pre- 
cipitated from  a  water  solution  by  the  addition  of  alcohol.  This  white 
precipitate  is  readily  dissolved  in  water  and  possesses  the  property  of 
inverting  cane  sugar  or  sucrose  quantitatively.  Invertase  is  an  impor- 
tant enzyme  in  the  fermentation  of  molasses  or  any  other  substance  con- 
taining sucrose.  Invertase  acts  only  in  a  slightly  acid  solution.  The 
best  temperature  for  its  action  is  about  55°  C. ;  it  is  slowly  destroyed  at 
about  65°  C.,  and  immediately  at  95°  C. 

Zymase. — This  enzyme  in  reality  forms  a  class  by  itself,  in  that  it 
possesses  the  property  of  converting  monosaccharid  sugars  into  alcohol 
and  carbon  dioxide.  The  presence  in  solution  of  the  enzyme  which 
Buchner  named  zymase,  and  which  is  the  cause  of  alcoholic  fermenta- 
tion, overthrows  to  a  great  extent  the  older  theories  which  regarded  the 
actual  cause  of  the  transformation  of  sugar  into  alcohol  and  carbon 
dioxide  as  a  vital  process  dependent  upon  the  actual  life  activities  of  the 
yeast  cell  itself. 

The  organized  ferments  or  vegetable  growths  may  be  divided  into 
three  classes:  first,  mould-growths;  second,  yeast-plants,  or  the  different 
species  and  varieties  of  Saccharomyces ;  and,  third,  bacteria,  belonging 
to  the  two  genera  Schizomycetes  and  Schizophycetes.  Tlie  most  im- 
portant fermentations  from  an  industrial  point  of  view  are  the  alcoholic, 
which  is  brought  about  mainly*  by  the  presence  of  ferments  of  the 
second  class,  and  the  acetic  and  lactic,  which  are  brought  about  by  fer- 
ments of  the  third  class.  Upon  the  alcoholic  fermentation  depend  three 
important  groups  of  industries, — viz.,  the  manufacture  of  malt  liquors, 
the  manufacture  of  wines,  and  the  manufacture  of  ardent  spirits,  or 

distilled  liquors.     Upon  the  acetic  fermentation  depends  the  manufac- 

^ 

*  Buchner  (1897)  has  shown  clearly  that  there  is  present  in  the  yeast-cells,  even 
when  dead,  a  soluble  ferment  or  enzyme  capable  of  developing  the  alcoholic  fermenta- 
tion. 


NATURE  AND  VARIETIES  OF  FERMENTATION.  205 

ture  of  different  varieties  of  vinegar,  and  upon  the  lactic  fermentation 
the  manufacture  of  cheese  and  other  milk  products. 

The  alcoholic  fermentation  is  always  meant  when  we  use  the  word 
fermentation  in  the  narrower  sense,  as  with  reference  to  the  change 
which  starch  and  saccharine  bodies  most  generally  undergo.  In  this  fer- 
mentation, the  action  of  the  yeast-plant  seems  to  differ  according  to  the 
variety  of  sugar  presented  to  it.  Dextrose  is  most  immediately  acted 
upon,  the  main  reaction  being  CoH^O,,  =  2C2HGO  -f  2CO,,  although,  as 
Pasteur  first  showed,  side-products  like  glycerine  and  succinic  acid  are 
also  formed,  and  in  practice  only  about  ninety-five  per  cent,  of  the  dex- 
trose is  decomposed  by  the  main  reaction.  Cane-sugar  is  not  immediately 
fermentable.  If  it  has  been  previously  exposed  to  the  action  of  dilute 
acids,  it  is  changed  into  invert  sugar,  which  then  acts  like  dextrose.  The 
yeast-plant  can  effect  the  same  change  itself.  Invertin  (or  invertase,  as 
it  is  also  termed)  is  a  soluble  ferment  existent  in  yeast.  It  has  the  prop- 
erty of  rapidly  and  completely  effecting  the  transformation  of  cane- 
sugar  into  invert  sugar,  but  is  without  sensible  action  on  dextrose,  levu- 
lose,  maltose,  or  milk-sugar.  Towards  dextrine  its  action  is  not  so 
certainly  negative. 

The  conditions  of  the  activity  of  the  yeast-plant  have  been  studied 
by  many  chemists,  but  notably  by  Pasteur.  It  has  been  found  that  if 
an  abundance  of  air  is  supplied  the  plant  grows  and  multiplies  but  fer- 
mentation proceeds  very  slowly,  when  the  supply  of  air  is  limited,  the 
fermentation  proceeds  more  rapidly  while  the  growth  of  the  cells  is 
largely  arrested,  and  that  in  the  absence  of  air  the  fermentation  proceeds 
with  greatest  rapidity,  although  the  plant-cells  do  not  grow  any  longer, 
but  gradually  disintegrate  and  die.  Pasteur's  dictum,  that  "fermenta- 
tion is  the  consequence  of  life  without  air, ' '  is  no  longer  taken  as  strictly 
accurate,  as  with  the  cessation  of  the  growth  and  extension  of  the 
yeast-plant  (which  is  dependent  upon  air  like  the  life  of  any  other 
plant),  although  its  fermentation  activity  then  becomes  greatest,  it  begins 
at  the  same  time  a  decay  which  leaves  it  after  a  time  dead  and  inactive. 

The  genus  Saccharomyces  has  already  been  alluded  to  as  the  active 
agent  in  the  alcoholic  fermentation.  The  species  Saccharomyces  cerevisice 
is  generally  known  as  the  special  beer  ferment  and  the  Saccharomyces 
ellipsoideus  as  the  wine  ferment.  Moreover,  of  the  Saccharomyces  cere- 
visice,  two  well-marked  varieties  have  been  recognized.  The  one  is  the 
most  active  at  the  ordinary  temperature  (16°  to  20°  C.),  and  carries 
through  its  fermentative  work  in  from  three  to  four  days;  the  other 
works  at  a  lower  temperature  (6°  to  8°  C.)  and  the  fermentation  is  much 
slower.  The  first,  placed  in  a  saccharine  liquid,  is  carried  by  the  carbon 
dioxide  which  it  liberates  to  the  surface  of  the  liquid,  where  it  continues 
its  activity ;  it  is  therefore  known  as  a  surface  or  top  yeast.  The  second, 
on  the  contrary,  is  not  carried  up,  and  rests  during  its  entire  activity 
on  the  bottom  of  the  fermenting  vessel,  and  is  hence  called  a  bottom 
yeast.  Two  quite  distinct  methods  of  beer-brewing  are  practised  (see 
p.  212),  depending  upon  the  use  of  the  one  or  the  other  of  these  varieties 
of  yeast.  It  has  been  found,  however,  in  practice  that,  even  when  a  top 


206 


FERMENTATION  INDUSTRIES. 


FIG.  57. 


Saccharomyces  cerevisise. 
(After  Hansen.) 


Saccharomyces  cerevisise.    Ascospores. 
(After  Hansen.) 


Saccharomyces  ellipsoideus. 
(After  Hansen.) 


Saccharomyces  ellipsoideus.    Ascospores. 
(After  Hansen.) 


Saccharomyces  Pastorianus. 
(After  Hansen.) 


Saccharomyces  Pastorianus.    Ascospores. 
(After  Hansen.) 


NATURE  AND  VARIETIES  OF  FERMENTATION. 


207 


yeast  is  used  exclusively  or  a  bottom  yeast  exclusively,  the  results  are  not 
always  uniform.  These  anomalies  are  now  made  clear  through  the  re- 
searches of  E.  Ch.  Hansen,  of  Copenhagen,  who  has  applied  the  methods 
of  pure  cultivation  introduced  by  bacteriologists  to  the  study  of  the 
yeast-plant.  He  has  found  that  if  a  single  yeast-cell  of  one  of  the  better 
varieties  of  Saccharomyces  be  cultivated  with  the  precautions  needed  to 
exclude  what  is  called  "wild  yeast  "  (germs  present  in  the  air,  notably 
in  the  summer  months),  absolutely  uniform  results  can  be  gotten  in 
brewing.  Beginning  in  1883,  he  has  developed  the  study,  and  it  has 

FIG.  58. 


"3 


MASH. 
POTATO    MASH 

EN6LISH    BEER. 

LA6CK  BEE* 


now  been  accepted  by  most  of  the  leading  authorities  on  fermentation. 
He  first  decribed  six  species :  Saccharomyces  cerevisice  I.,  Saccharomyces 
Pastorianus  I.,  II.,  and  III.,  Saccharomyces  ellipsoideus  I.  and  II.,  of 
which  the  second,  fourth,  and  sixth  cause  bitterness  and  turbidity  (so- 
called  "diseases  "  in  beer).  He  has  since*  increased  the  list  of  varie- 
ties of  ferments  studied  to  forty,  including  both  top  and  bottom  yeasts, 
ferments  similar  to  yeast  but  not  belonging  to  the  genus  Saccharomyces, 
and  forms  of  mould-growh.  He  divides  the  representatives  of  each 
genus  into  two  groups  according  as  they  secrete  invertin  or  not. 

Fresh  yeast  resembles  a  dirty  yellowish-gray  sediment  of  unpleasant 
odor  and  acid  reaction,  made  up  of  an  immense  number  of  vegetable 
cells.  Three  of  the  pure  culture  varieties  of  yeast-plant  as  obtained  by 
Hansen  are  shown  in  the  illustration  Fig.  57,  together  wrth  the  special 
appearance  of  the  ascospores  of  the  same.  Of  these,  the  Saccharomyces 
*  Journ.  Soc.  Chem.  Tnd.,  1889,  p.  471. 


208  FERMENTATION  INDUSTRIES. 

cerevisice  and  Saccliaromyces  Pastorianus  are  beer  ferments,  while  the 
Saccharomyces  ellipsoidcus  is  the  wine  ferment.  For  many  purposes 
(bread-baking,  use  in  distilleries,  etc.),  the  ferment  is  prepared  as  com- 
pressed yeast  in  cakes,  generally  with  the  addition  of  potato  starch. 

The  special  conditions  of  the  alcoholic  fermentation  are:  first,  an 
aqueous  solution  of  sugar  of  the  strength  of  one  part  sugar  to  four  to 
ten  parts  water;  second,  the  presence  of  a  yeast  ferment.  If  this  is  not 
added  already  developed  and  active,  or  if  the  fermentation  is  to  be 
spontaneous, — that  is,  brought  about  by  spores  from  the  air, — the  condi- 
tions for  the  development  of  these  spores  must  also  be  present.  There 
must  be  protein  compounds  and  phosphates  of  the  alkalies  and  alkali 
earths.  Thirdly,  the  temperature  must  remain  within  the  limits  5°  to 
30°  C.,  or,  more  generally,  from  9°  to  25°  C.  Above  30°  C.  the  alcoholic 
fermentation  readily  passes  into  the  "butyric  and  other  decomposition. 

The  effect  of  temperature  upon  the  several  different  ferments  is 
shown  in  the  graphic  illustration  of  Fig.  58,  which  represents  also  the 
influence  of  temperature  upon  the  decomposition  of  starch  by  diastase. 
On  the  right  side  of  the  figure,  the  regularly-dotted  line  represents  the 
yeast  curve.  A  slight  fermentation  is  already  induced  at  a  temperature 
very  little  over  the  melting  point  of  ice.  As  the  temperature  rises  its 
activity  increases  until  the  maximum  is  reached,  at  about  33°  C.  (92° 
F.),  when  it  diminishes  down  to  nothing  again,  and  at  50°  C.  (122°  F.) 
or  thereabouts  it  is  killed.  The  activity  of  the  acetic  ferment  is  repre- 
sented at  the  same  time  by  the  irregularly-dotted  line,  and  that  of  the  lactic 
ferment  by  the  uniform  black  line. 

B.    MALT  LIQUORS  AND  THE   INDUSTRIES  CONNECTED 

THEREWITH. 

I.   Raw  Materials. 

1.  MALT. — Malt  is  prepared  by  steeping  barley  or  other  grain  in 
water,  and  allowing  it  to  germinate  in  order  to  change  the  character  of 
the  albuminoids  and  develop  the  ferment  diastase,  which  then  begins  to 
act  upon  the  starch,  the  germination  and  change  being  stopped  at  a 
certain  stage  by  heating  in  a  kiln.  The  composition  of  the  unmalted 
barley  was  given  among  other  cereals  on  p.  186.  The  changes  which  it 
undergoes  in  composition  by  the  process  of  malting  will  be  seen  by  com- 
paring this  with  the  two  analyses  of  pale  malt  following,  which  are  by 
0  'Sullivan : 

No.  I.  No.  II. 

Starch    44.15  45.13 

Other  carbohydrates   (of  which  sixty  to  seventy  per  cent,  consist  of 

fermentable  sugar),  inulin  and  similar  bodies  soluble  in  cold  water  21.23  19.39 

Cellular  matter 11.57  10.09 

Fat    1.65  1.96 

Albuminoids  soluble  in  water  6.71  5.31 

Albuminoids  insoluble  in  water  6.38  8.49 

Ash    2.60  1.92 

Water    5.83  7.47 

100.00       100.00 


MALT  LIQUORS.  209 

0 'Sullivan  states  that  malt  contains  no  ready-formed  dextrine,  but 
that  it  does  contain  from  sixteen  to  twenty  per  cent,  of  fermentable 
sugars,  of  which  about  one-half  is  probably  maltose,  and  due  to  the 
transformation  of  starch  in  the  malting  process,  while  the  remainder 
exists  ready  formed  in  the  barley,  and  is  not  identical  with  the  sugar 
produced  in  the  malting. 

Besides  the  diastase,  a  second  soluble  ferment  is  formed  during  the 
malting  process,  the  so-called  peptase,  which  in  the  mash  process  changes 
the  proteids  of  the  malt  into  peptones  and  parapeptones,  which  give 
nutritive  value  to  the  beer. 

A  high  percentage  of  starch  in  the  barley  to  be  used  for  brewing  is 
desirable  in  order  that  when  malted  it  may  yield  a  large  amount  of 
"extractive  matter."  According  to  Lintner  and  Aubry,*  a  good  malt 
should  yield  at  least  seventy-one  per  cent,  of  extract  reckoned  on  the 
weight  of  dry  substance.  This  determination  of  the  value  of  a  sample 
of  malt  is  one  of  the  most  necessary  of  analytical  tests  for  the  malster  or 
brewer.  (See  p.  219.) 

Well-malted  barley  is  always  yellow  or  amber-colored,  shading  to 
brown.  On  breaking  the  grain,  the  interior  should  be  of  a  pure  white 
color  and  floury  appearance,  except  when  the  drying  has  been  inten- 
tionally carried  so  far  as  to  partially  caramelize  the  sugar. 

Malted  wheat,  corn,  and  rice  are  at  times  used  as  partial  substitutes 
for  the  barley  malt,  as  well  as  potato  starch  and  starch-sugar.  The  use 
of  patented  maltose  and  maltose-dextrine  preparations  has  already  been 
referred  to.  (See  p.  193.) 

2.  HOPS. — Hops  are  the  female  unfructified  blossoms  (catkins)  of  the 
hop-plant  (Humulus  lupulus).  Under  the  thin  membranous  scales  of 
the  strobile  or  catkin  is  an  abundance  of  a  yellowish  resinous  powder, 
consisting  of  minute  sessile  grains,  to  which  the  name  lupulin  has  been 
given.  The  active  principles  of  the  hops,  contained  mainly,  but  not 
exclusively,  in  the  lupulin,  are:  First,  the  ethereal  oil,  which  is  present 
to  the  amount  of  .3  per  cent,  in  the  air-dried  hops.  This  is  yellowish, 
of  strong  odor  and  of  burning  taste.  It  consists  of  a  hydrocarbon, 
C5H8,  and  an  oxygenized  oil,  C10H18O2,  which  by  atmospheric  oxidation 
becomes  valerianic  acid,  C5H1002,  to  which  old  hops  owe  their  odor. 
Second,  the  lupulin  also  contains  a  resinous  bitter  principle,  which  is 
easily  soluble  in  alcohol,  but  difficultly  soluble  in  water,  and  extremely 
bitter.  This  is  supposed  to  be  an  oxidation  product  of  lupulinic  acid, 
which  can  be  gotten  in  white  crystals,  speedily  becoming  resinous.  Both 
the  acid  and  its  oxidation  products  seem  to  be  held  dissolved  in  the 
ethereal  oil.  Hops  also  contain  tannic  acid  of  a  variety  allied  to  mori- 
tannic  acid  and  turning  iron  salts  green.  Analyses  of  two  well-known 
Bohemian  varieties  of  hops  are  given. t 

The  blossoms  are  produced  in  August,  and  the  strobiles  are  fit  for 
gathering  from  the  beginning  of  September  to  the  middle  of  October, 
according  to  the  weather.  The  prompt  drying  of  the  fresh-picked  hops 

*  Jahresber.  Chem.  Tech.,  1882,  pp.  840  and  851. 
fKonig,  Nahrungs-  und  Genussmittel,  vol.  ii,  p.  409. 
14 


210 


FERMENTATION  INDUSTRIES. 


is  necessary  in  order  that  they  may  be  safely  baled.  This  drying  takes 
place  by  the  aid  of  hot  air  in  a  so-called  hop-kiln  at  a  temperature  of 
about  40°  C.,  the  hops  being  repeatedly  turned  with  a  light  wooden 
shovel  as  they  lie  spread  out  upon  a  false  or  perforated  floor.  When 


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dry  they  are  pressed  by  hydraulic  presses  into  compact  bales.  Hops  are 
also  often  treated  with  sulphurous  acid  gas  from  burning  sulphur  to 
preserve  them,  although  this  sulphuring  is  oftener  used  with  old  hops 
for  the  purpose  of  brightening  them  in  color  and  improving  their 
appearance. 

A  number  of  bitter  principles  have  been  mentioned  as  used  at  times 
as  substitutes  for  hops  in  beer-brewing,  although  it  is  doubtful  if  such 
substitution  is  much  practised.  Among  these  substitutes  have  been  noted 
quassia,  gentian,  picrotoxin,  the  bitter  principle  of  Cocculus  Indicus, 
colchicum,  wormwood,  and  picric  acid. 

3.  WATER. — The  water  used  in  malting  and  brewing  must  be  adapted 
for  the  purpose  in  order  to  get  good  results.  A  pure  and  soft  water  or  a 
moderately  hard  calcareous  water  will  do,  but  it  is  indispensable  that 
the  water  be  perfectly  free  from  organic  impurities.  Continental 
brewers  use  soft  waters  most  generally  in  brewing  beers,  while  English 
brewers  prefer  gypsum  waters  for  their  ales  which  are  specially  designed 
to  keep.  This  is  shown  in  the  character  of  the  water  of  Burton-on- 
Trent,  which  contains  notable  quantities  of  calcium  and  magnesium  sul- 
phates, calcium  carbonate,  and  sodium  chloride. 

n.  Processes  of  Manufacture. 

1.  MALTING  OF  THE  GRAIN. — Although  malt  has  been  described  as 
a  raw  material  of  the  brewing  industry,  the  preparation  of  it  from  the 
raw  grain  is  a  process  so  closely  connected  with  the  success  of  brewing 
that  it  must  be  described,  and  especially,  too,  because  it  is  often  combined 
under  the  same  direction  as  the  brewing  process.  The  process  of  chang- 
ing barley  into  malt  is  to  be  divided  into  four  stages :  the  steeping,  the 
couching,  the  flooring,  and  the  kiln-drying.  The  first  three  of  these 
stages  have  to  do  with  the  germination  or  development  of  the  acrospire, 
or  plumule,  which  as  it  develops  brings  about  great  changes  in  the 
chemical  constitution  of  the  grain,  developing  from  the  albuminoid 
matter  the  diastase,  which  in  turn  begins  to  act  upon  the  starch,  forming 
from  it  maltose  and  dextrine.  At  the  same  time  during  the  germination 
atmospheric  oxidation  is  going  on  at  the  expense  of  the  starch  of  the 


MALT  LIQUORS.  211 

grain,  water  and  carbon  dioxide  being  steadily  given  off.  When  the 
development  of  the  diastase  is  supposed  to  have  reached  the  right  point, 
which  can  only  be  judged  of  by  the  growth  of  the  acrospire,  or  germ,  the 
fourth  stage  of  the  process  is  reached,  and  the  germ  must  be  killed  by 
heat,  which  is  done  in  the  kiln-drying. 

The  first  process  of  steeping  is  to  give  the  grain  sufficient  moisture  to 
allow  germination  to  begin.  For  that  purpose  it  is  put  into  large  iron, 
or  cemented  vats.  These  are  half  filled  with  water  and  the  grain  added 
with  constant  stirring.  The  sound  grains  sink  shortly  under  the  water, 
and  the  dead  or  imperfect  grains  float  and  can  be  removed.  The  water 
soon  takes  color  and  odor,  and  must  be  replaced  by  fresh  water.  The  dura- 
tion of  the  steeping  is  usually  forty-eight  to  seventy-two  hours,  depend- 
ing upon  the  temperature,  and  in  winter-time  or  with  older  barley  may 
last  considerably  longer.  The  end  of  the  treatment  may  be  told  by  noting 
the  character  of  the  grain.  It  has  swollen  and  become  nearly  sufficiently 
soft  to  allow  of  being  pierced  with  a  needle  and  yet  exuding  no  juice-. 
It  has  gained  from  forty  to  fifty  per  cent,  in  weight  and  increased  from 
twenty  to  twenty-four  per  cent,  in  bulk.  To  offset  this  gain  due  to  water 
absorption,  it  has  lost  from  one  to  two  per  cent,  of  its  substance,  partly 
carried  off  in  the  steep  water  and  partly  given  off  as  gas.  The  water  is 
then  run  off,  and  after  draining  it  is  turned  upon  the  couching-floor, 
where  it  remains  at  first  in  heaps  of  from  fifteen  to  twenty-four  inches 
in  depth.  Here  it  soon  begins  to  heat  up,  and  a  rise  in  temperature  of 
from  7°  to  10°  takes  place.  It  also  begins  to  "sweat,"  and  gives  off  an 
abundance  of  carbon  dioxide,  and  an  agreeable  cucumber-like  odor  is 
recognizable.  The  germination  is  now  under  way  and  the  rootlets  shoot 
out.  The  "couching  "  stage  lasts  from  twenty-four  to  thirty-six  hours, 
and  during  that  time  the  grain  must  be  turned  several  times.  The 
heated  barley  must  now  be  spread  on  the  floor  in  shallow  layers  so  as  to 
check  somewhat  the  rate  of  growth  of  the  germ,  and  must  be  turned 
from  four  to  six  times  a  day  as  the  growth  proceeds.  The  depth  of  the 
layer  is  at  the  same  time  reduced  from  fifteen  to  four  or  five  inches. 
During  this  time  the  germinating  grain  must  have  an  abundance  of 
air.  The  process  lasts  from  seven  to  ten  or  even  twelve  days,  according 
to  the  season  of  the  year,  and  its  termination  is  decided  by  the  length  of 
the  germ,  which  must  be  about  two-thirds  that  of  the  grain.  The  loss 
in  weight  during  the  germinating  process,  according  to  Lintner,  is  ten 
per  cent,  of  the  weight  of  the  grain.  The  loss  comes  mainly  upon 
the  starch,  which  has  in  part  been  changed  into  maltose  and  dextrine, 
but  has  mostly  been  oxidized  to  water  and  to  carbon  dioxide.  To  more 
efficiently  remove  the  carbon  dioxide  which  would  interfere  with  the 
germinating  process  and  to  prevent  too  strong  a  heating,  the  pneumatic 
process  of  malting  has  been  proposed  by  Galland.  In  this  process  the 
steeped  barley  is  placed  on  a  perforated  floor  in  thick  layers,  and  a 
regulated  current  of  moist,  well-cooled  air  is  kept  passing  through  it. 
This  process  is  now  replacing  the  other  quite  largely.  Still  another 
form  of  mechanical  malting  apparatus  is  that  of  Saladin.*  The  germi- 

*  Dammer's  Handbuch  der  Chemischen  Technologic,  vol.  iii,  p.  632. 


212  FERMENTATION  INDUSTRIES. 

nation  must  now  be  stopped  promptly,  lest  it  go  too  far  at  the  expense 
of  the  starch  of  the  grain,  and  this  is  best  effected  by  heat.  The  germi- 
nating grain  may,  however,  be  simply  dried  thoroughly  in  the  air  and 
the  rootlets  removed  by  mechanical  means.  This  constitutes  air-dried 
malt,  which  is  used  for  some  purposes.  Most  generally  it  is  dried  in  a 
kiln  at  a  considerably  higher  temperature.  This  must  be  gradually 
applied,  as  if,  while  the  raw  malt  were  full  of  moisture,  it  were  to  be 
heated  strongly,  the  starch  would  be  gelatinized  and  the  grain  made 
tough,  hard,  and  glassy.  It  is  therefore  heated  first  to  about  90°  F.,  and 
this  is  gradually  raised  to  150°  F.,  or  even  in  some  cases  to  180°  F.  A 
light  gradual  heat  produces  a  "pale  "  malt,  a  stronger  heat  "yellow  " 
or  "pale  amber,"  and  then  "amber"  and  "brown"  malt.  The  kiln 
may  have  two  floors,  on  the  upper  and  cooler  of  which  the  moist  malt 
loses  its  water  and  then  passes  on  to  the  lower  and  hotter  floor,  where 
it  is  heated  to  the  higher  limit  requisite  for  developing  its  empyreumatic 
odor  and  flavor,  or  the  heating  may  all  be  effected  on  a  single  floor,  in 
which  case  more  time  is  needed  for  the  several  stages  of  heating.  Black 
malt  used  for  coloring  is  heated  in  revolving  coffee-roasters,  and  most  of 
the  sugar  is  caramelized. 

2.  PREPAR/VTION  OF  THE  WORT. — The  malt  after  being  cleansed  and 
crushed  (not  ground  fine)  is  ready  for  use  in  what  is  known  as  the 
mashing  process.  This  is  designed  not  merely  to  extract  the  maltose 
and  dextrine  of  the  malt,  but  mainly  to  allow  the  diastase  of  the  malt 
to  act  upon  the  starch,  changing  it  into  maltose  and  dextrine  and  the 
peptase  to  form  peptones  from  the  proteids.  It  must  therefore  be  car- 
ried out  under  such  conditions  of  temperature  and  dilution  as  have  been 
found  to  be  most  favorable  for  effecting  these  purposes.  We  have 
already  seen  (p.  207)  that  the  action  of  diastase  is  most  effective  at  about 
62.5°  C.  (144.5°  F.),  and  therefore  at  a  temperature  not  much  above 
this  is  the  infusion  most  successfully  made.  At  a  temperature  of  over 
75°  C.  its  power  is  destroyed.  Two  quite  distinct  processes  for  mashing 
are  at  present  followed:  the  infusion,  or  thin  mash,  and  the  decoction, 
or  thick  mash,  process.  The  first  is  used  in  England  and  France,  the 
second  in  Bavaria,  Bohemia,  and  the  principal  brewing  centres  of  the 
Continent.  Both  are  used  in  this  country.  In  the  infusion  process, 
water  at  60°  to  70°  C.  is  run  into  the  mash-tub,  a  vessel  provided  with 
false  bottom  and  mechanical  agitation,  the  crushed  malt  added  and 
stirred  in,  and  then  additional  hotter  water,  so  that  a  temperature  of 
70°  C.  (158°  F.)  is  gradually  attained.  This  is  maintained  for  some 
time  with  constant  agitation  of  the  liquid,  so  that  the  diastase  may  have 
time  to  act  upon  the  starch.  The  completion  of  this  action  is  deter- 
mined by  taking  a  few  drops  of  the  wort  from  time  to  time  and  testing 
with  iodine  solution,  which  finally  produces  no  color  on  mixing.  The 
clear  infusion  is  now  run  off  from  under  the  f,alse  bottom  of  the  tub 
to  the  copper  boilers,  and  the  malt  again  covered  with  hot  water  and 
mashed  for  one-half  to  one  hour  longer  at  70°  C.  or  somewhat  higher 
now.  When  this  is  run  off,  hot  water  at  200°  F.  is  sprinkled  upon  the 
malt  from  a  revolving  "sparger  "  and  allowed  to  drain  off.  The  wort 


MALT  LIQUORS.  213 

from  this  third  mash  is  not  always  added  to  that  of  the  first  and  second 
mashes,  but  is  used  to  mash  a  fresh  quantity  of  malt. 

In  the  Bavarian  thick-mash  process,  the  malt  is  put  in  the  mash-tub 
with  some  cold  water,  and  then  by  the  addition  of  boiling  water  is 
brought  to  35°  C.  A  third  of  the  softened  malt  is  then  taken  out  and 
brought  gradually  to  boiling  with  water  in  the  copper.  After  one-half 
to  three-quarters  of  an  hour's  boiling,  the  half  of  this  is  then  returned 
to  the  mash-tub  and  thoroughly  agitated  with  what  remained  there.  The 
temperature  of  the  mash-tub  is  thereby  brought  to  about  50°  C.  A 
second  portion  of  the  thick  mash  is  again  taken  out  and  boiled  in  the 
copper  for  three-quarters  to  one  hour,  when  the  greater  part  is  returned 
to  the  mash-tub  and  thoroughly  mixed,  bringing  up  the  temperature 
here  to  65°  C.  The  thinner  part  of  the  mash,  or  clear  wort,  is  now  run 
off  and  boiled  in  the  copper  for  fifteen  minutes  and  returned,  whereby 
the  temperature  of  the  mash-tub  is  brought  to  75°  C.  This  is  now  left 
at  rest  for  an  hour  to  an  hour  and  a  half,  and  then  the  wort  is  run  off 
to  the  copper.  The  malt  is  washed  by  the  sparger,  and  so  the  saccharine 
liquor  adhering  displaced.  The  whole  process  is  easily  understood  by 
reference  to  Fig.  59,  in  which  A  is  the  mash-tub  and  C  the  copper  for 
boiling  up  the  successive  portions  taken  from  A. 

It  is  obvious  that  in  the  thick-mash  process  that  portion  of  the  dias- 
tase contained  in  the  material  which  is  taken  out  and  boiled  is  destroyed, 
but  the  boiling  thoroughly  disintegrates  the  malt  and  converts  its  starch 
into  a  paste.  When  this  is  returned  to  the  mash-tub,  it  is  very  rapidly 
acted  upon  by  the  remaining  diastase,  of  which  there  is  quite  sufficient, 
and  changed  into  maltose  and  dextrine.  By  the  thick-mash  process,  the 
sugar  formation  is  held  in  check  and  the  amount  of  extract  increased. 

In  the  mash  process  the  diastase  acts  upon  the  starch  of  the  malt, 
changing  it  into  maltose  and  dextrine.  The  ratio  of  these  products  to 
each  other  changes  according  to  the  temperature  used  in  the  mashing. 
Moreover,  as  dextrine  is  not  fermented  in  the  main  fermentation  and 
only  partially  in  the  after-fermentation,  some  of  it  remaining  in  the 
finished  beer,  this  matter  of  temperature  of  mashing  is  obviously  of 
importance  for  the  character  of  the  beer. 

According  to  Marker  and  Schultze,  at  temperatures  up  to  65°  C. 
the  reaction  takes  place  as  follows: 

4C6H1005  +  2HaO  =  C18H34017  +  C6H1005; 

that  is,  four  molecules  of  starch  react  with  two  molecules  of  water  to 
form  three  molecules  of  fermentable  sugar  (maltose)  and  one  molecule 
of  dextrine.  On  the  other  hand,  at  temperatures  over  65°  C.  the  reaction 

becomes 

6CGH1005  +  2H20  =  C18H3401T  +  3C6H1005 ; 

that  is,  six  molecules  of  starch  react  with  two  molecules  of  water  to 
form  one  molecule  of  maltose  and  three  molecules  of  dextrine. 

The  results  of  practice,  at  all  events,  show  that  in  the  infusion  pro- 
cess, which  takes  place  at  low  temperatures,  beers  of  lower  extract  per- 
centage are  formed  which  is  in  part  due  to  this  difference  in  the  produc- 
tion of  dextrine  just  illustrated.  A  second  drawback  of  the  infusion 


214 


MALT  LIQUORS.  215 

process  is  that  it  is  difficult  to  avoid  here  a  larger  formation  of  lactic 
acid,  due  to  the  more  prolonged  action  of  the  water  upon  the  malt,  which 
is  at  just  the  temperature  (about  50°  C.)  favorable  for  the  formation  of 
lactic  acid.  At  the  temperature  of  the  infusion  process  the  nitrogenous 
compounds  are  also  less  completely  decomposed  than  in  the  decoction 
process,  so  that  a  beer  obtained  by  the  former  process  furnishes  a  more 
nutritious  ground  for  the  growth  of  bacterial  ferments  than  the  latter. 

As  the  amount  of  diastase  in  the  malt  is  sufficiently  large  to  saccha- 
rify considerably  more  starch  than  that  contained  in  the  malt  itself, 
at  times  unmalted  grain  and  starch-containing  cereals  are  added.  The 
end  to  be  attained  is  not  only  the  saving  of  the  cost  of  a  portion  of  the 
malt,  but  to  obtain  a  beer  richer  in  extract  and  therefore  of  better  keep- 
ing quality. 

These  malt  substitutes  are  generally  cereals  rich  in  starch,  such  as 
corn  and  rice.  At  times  unmalted  barley,  rye,  oats,  and  even  potatoes 
have  also  been  used.  Care  must  be  taken  that  the  saccharification  in 
these  cases  of  the  use  of  corn  and  rice  is  made  as  complete  as  possible, 
and  hence  it  must  not  be  overlooked  that  the  starch  of  both  corn  and 
rice  requires  a  higher  temperature  (71°  C.)  for  its  complete  changing 
into  fermentable  sugar.  The  corn  or  rice  before  use  should  be  shelled, 
deprived  of  the  germ,  and  crushed,  so  as  to  facilitate  the  liberation  of  its 
starch.  The  amount  of  malt  substitute  thus  used  should  not  in  any  case 
exceed  thirty  per  cent,  of  the  weight  of  the  malt.  In  some  countries,  as 
in  Bavaria,  the  use  of  malt  substitutes  is  strictly  prohibited  by  law. 

The  character  of  the  wort  is  to  be  controlled  by  the  use  of  the  Bal- 
ling saccharometer  (see  p.  179),  as  the  specific  gravity  of  aqueous  malt 
extract  corresponds  to  that  of  cane-sugar  solutions  of  the  same  per- 
centage strength. 

3.  BOILING  AND  COOLING. — The  wort  is  drained  off  from  the  malt- 
residue,  or  "draff,"  and  run  into  the  copper  boiler,  where  it  is  boiled, 
while  the  hops  are  added  at  once  in  amount  varying  from  one  to  three 
(or  more  in  the  case  of  India  ales)  parts  to  the  hundred  of  malt,  light 
beers  taking  the  least  amount,  lager  beers  next,  and  heavy  export  beers 
the  largest  amount.  If  the  amount  of  hops  is  to  be  calculated  after  the 
wort  has  been  formed,  0.25  to  0.30  kilos,  may  be  taken  to  the  hectolitre 
of  wort  of  10  to  12  per  cent.,  0.40  to  0.60  kilos,  to  the  hectolitre  of  wort 
of  12  to  15  per  cent.,  and  0.70  to  0.80  kilos,  to  the  hectolitre  of  stronger 
worts. 

The  boiling  accomplishes  several  desirable  changes  in  the  wort:  first, 
the  unhydrolized  protein  material  present  separates  out,  which  result  is 
facilitated  by  the  action  of  the  tannic  acid  of  the  hops,  which  also  throws 
out  any  unchanged  starch;  second,  the  wort  is  concentrated;  third,  the 
valuable  constituents  of  the  hops  (hop-bitter  and  ethereal  oil)  are  taken 
up  by  the  wort  and  give  to  the  beer  its  taste,  aroma,  and  keeping  quali- 
ties. The  time  of  boiling  varies  considerably,  requiring  to  be  longer  for 
worts  prepared  by  the  infusion  process  than  for  those  by  the  decoction 
process.  From  one  to  two  hours  is  generally  sufficient  where  the  worts 
do  not  specially  need  to  be  concentrated.  Too  long  boiling  is  injurious, 
as  the  volatile  oil  of  the  hops  may  be  lost  thereby.  Of  one  hundred  parts 


216  FERMENTATION  INDUSTRIES. 

of  dry  malt,  sixty-five  to  eighty  per  cent,  are  taken  up  as  extract  in  the 
wort;  of  one  hundred  parts  of  hops,  twenty  to  thirty  parts. 

The  wort  is  now  to  be  cooled  preparatory  to  the  fermentation.  This 
cooling  must  be  effected  as  rapidly  as  possible,  so  that  the  lactic  fermen- 
tation and  similar  changes  may  not  take  place.  The  cooling  is  generally 
effected  in  very  shallow  wide  tanks,  which  are  placed  where  a  good 
circulation  of  air  can  be  assured.  From  these  tanks  the  still  warm  wort 
is  often  run  through  a  circuit  of  pipes  cooled  by  ice-water  flowing  around 
them,  or  is  run  in  thin  streams  (known  as  a  "beer  fall  ")  over  a  series 
of  pipes  through  which  cold  water  or  chilled  brine  from  the  refriger- 
ating apparatus  circulates.  Such  an  arrangement  has  now  come  into 
general  use  in  large  breweries  provided  with  artificial  refrigeration.  Of 
course,  in  such  a  method  of  cooling  the  wort  is  exposed  for  a  consider- 
able time  to  impure  air  containing  sp'ores,  which,  getting  into  the  liquid, 
may  afterwards  affect  the  fermentation.  In  all  cases  where  Hansen's 
pure  yeast  is  to  be  employed  the  wort  must  be  cooled  in  vessels  to  which 
only  sterilized  air  has  access.  For  an  arrangement  of  this  kind,  see 
Wagner's  "Chemical  Technology,"  13th  ed.,  p.  911.  It  is  thus  cooled 
down  to  the  point  needed  for  the  beginning  of  the  fermentation.  This 
point  depends  upon  the  character  of  the  fermentation,  whether  with  top 
yeast  or  bottom  yeast;  for  the  latter  it  must  be  some  8°  to  10°  C.  below 
that  needed  for  the  former.  The  cooled  wort  is  now  allowed  to  deposit 
a  sediment  of  coagulated  albuminoids,  particles  of  hops,  etc.,  which  were 
suspended  in  it  when  the  cooling  began.  This  sediment  is  gathered  and 
pressed  and  the  liquid  added  to  the  rest  of  the  wrort. 

4.  FERMENTATION  OP  THE  WORT. — The  wort  may  either  be  left  to 
spontaneous  fermentation  depending  upon  the  spores  of  yeast  ferments, 
which  are  always  present  in  the  air  of  a  brewery,  or  it  is  started  into 
fermentation  by  the  addition  of  yeast.  The  former  method  is  followed 
in  Belgium,  but  in  the  great  majority  of  cases  elsewhere  fermentation  is 
incited  by  the  direct  addition  of  a  suitable  yeast.  As  stated  before  in 
the  section  on  the  nature  of  fermentation  (see  p.  205),  there  are  two 
radically  different  methods  of  carrying  out  this  process  in  practice ;  the 
surface  fermentation  and  the  bottom  fermentation.  The  first  of  these,, 
followed  almost  exclusively  in  England  for  all  malt  liquors  and  in  this 
country  for  ales,  is  specially  adapted  for  worts  rich  in  maltose,  and 
takes  place  more  rapidly,  at  a  higher  temperature,  and  produces  more 
alcohol.  As  English  worts,  moreover,  are  usually  prepared  by  the 
infusion  method,  a  considerable  quantity  of  soluble  gluten  is  left  in  the 
liquor,  which  on  exposure  to  the  air,  as  in  half-empty  casks,  may  start 
the  acetic  fermentation,  or  souring.  The  second  of  these,  followed  in 
Germany  and  Austria  and  in  this  country  for  lager-beer,  proceeds  more 
slowly;  the  production  of  alcohol  is  restrained  by  the  low  temperature, 
and  as  the  fermentation  proceeds  with  freer  and  more  prolonged  access 
of  air,  the  yeast-plants  in  their  growth  consume  rthe  proteid  matter  asr 
food.  Consequently  there  is  less  albuminoid  matter  left  to  start  souring, 
and  the  beer  is  a  better-keeping  beer  than  those  prepared  by  the  more 
rapid  surface  fermentation.  Of  course,  the  proportion  of  malt  and  hops 
used  and  the  alcohol  percentage  also  come  into  consideration  in  the 


MALT  LIQUORS.  217 

matter  of  keeping  quality,  and  may  offset  the  advantage  just  mentioned. 
The  fermentation,  by  whichever  method  carried  out,  may  be  divided  into 
three  stages :  first,  the  main  fermentation,  which  begins  shortly  after  the 
addition  of  the  yeast,  and  is  specially  characterized  by  the  decomposition 
of  maltose,  the  formation  of  new  yeast-cells,  and  the  rise  of  temperature ; 
second,  the  after-fermentation,  in  which  the  decomposition  of  maltose 
still  continues,  but  the  formation  of  yeast-cells  has  nearly  ceased,  and 
the  yeast  particles  suspended  in  the  beer  settle  out  and  the  beer  clears; 
and,  third,  the  still  fermentation,  which  follows  the  completed  after-fer- 
mentation, in  which  maltose  is  still  decomposed  and  some  dextrine  is 
changed  into  maltose  by  what  diastase  is  present,  but  the  yeast-cells  are 
no  longer  formed. 

The  fermenting  vessels  are  great  oaken  tuns  holding  fifty  to  one 
hundred  barrels.  The  thick  froth,  or  magma,  of  yeast  is  added  in  amount 
varying  from  one-half  to  three-quarters  of  a  litre  per  one  hundred  litres 
of  wort  of  ten  to  fourteen  per  cent.  It  may  either  be  added  direct  to  the 
whole  body  of  the  wort  and  stirred  in,  or  may  be  mixed  with  a  smaller 
amount  of  the  wort,  allowed  to  stand  for  four  to  five  hours  until  fer- 
mentation starts,  and  then  the  mixture  added  to  the  main  body  of  the 
wort.  In  the  surface  fermentation  process,  the  main  fermentation  lasts 
from  four  to  eight  days,  during  which  time  the  temperature  must  be 
carefully  regulated  and  held  at  from  14°  to  18°  C.  The  surface  is  at 
first  covered  with  a  white  foam  which  rises  and  curls  and  breaks  into 
a  variety  of  forms.  The  temperature  rises  from  two  to  four  degrees,  and 
care  must  be  taken  to  control  and  reduce  this,  which  used  to  be  done  by 
the  use  of  conical  cans,  or  "swimmers,"  holding  ice,  floated  at  the  top 
of  the  tun,  cooling  the  mass,  but  the  tuns  are  now  cooled  just  as  the  fer- 
menting cellars  are,  by  artificial  means.  The  fermentation  is  not  allowed 
to  go  to  completion  at  this  initial  temperature,  but  the  beer  is  trans- 
ferred for  the  after  or  slower  fermentation  to  cooler  cellars  (of  about 
5°  C.),  where  it  is  put  into  storage-casks.  After  sufficient  time  here,  it 
is  drawn  into  casks  containing  beechwood  shavings,  to  which  isinglass 
is  sometimes  added  to  clear  it,  and  there  is  added  to  it  some  fresh  fer- 
menting beer  ("Krausen  "),  in  the  proportion  of  one  barrel  to  twenty, 
which  starts  a  new  fermentation,  giving  the  beer  its  "head."  In  the 
bottom  fermentation,  the  fermenting  cellar  is  kept  at  4°  to  5°  C.,  and 
the  main  fermentation  lasts  from  nine  to  ten  days.  The  after-fermen- 
tation follows  in  cellars  cooled  to  1°  to  2°  C.,  and  lasts  correspondingly 
longer. 

Berlin  weiss-beer  is  brewed  from  malted  wheat  to  which  some  malted 
barley  is  added,  and  is  fermented  at  relatively  higher  temperature  (16° 
to  24°  C.).  At  the  end  of  the  main  fermentation,  which  is  finished  in 
three  days,  it  is  transferred,  with  the  addition  of  some  fresh  fermenting 
beer,  to  tightly-stopped  stone  jugs,  in  which  the  after-fermentation  takes 
place.  In  eight  to  fourteen  days  it  is  in  condition  for  drinking.  It  is, 
of  course,  effervescing,  is  somewhat  turbid,  and  has  a  sour  taste  from 
lactic  acid  which  has  formed. 

5.  PRESERVATION  OF  BEER. — Beer  or  ale  intended  for  export  may  of 


218 


FERMENTATION  INDUSTRIES. 


course  have  keeping  qualities  imparted  to  it  in  its  manufacture  by  special 
addition  of  hops,  or  otherwise,  but  most  beers  can  have  their  keeping 
qualities  improved  by  direct  treatment  after  they  are  finished  beverages. 
This  is  most  legitimately  done  by  the  process  of  ''Pasteurizing,"  which 
consists  in  heating  the  beer  either  already  bottled  or  in  casks  to  a  tem- 
perature of  about  60°  C.,  which  apparently  kills  all  ferments  which 
develop  the  souring  of  beer.  Less  legitimate  and  forbidden  by  law  in 
most  countries  is  the  addition  of  salicylic  acid,  boric  acid,  or  calcium 
bisulphite. 

III.  Products. 

The  various  designations  that  have  been  given  to  malt  liquors  do  not 
necessarily  imply  distinctive  differences  in  the  character  of  the  product. 
They  represent  largely  the  different  usages  of  different  countries  and 
localities.  Thus,  in  England  Ale  was  at  one  time  brewed  without  hops, 
but  the  term  now  is  applied  to  a  beer  brewed  by  the  surface  fermentation 
process,  which  is  practically  the  only  method  used  in  England.  Porter 
has  now  come  to  mean  a  dark  malt  liquor,  made  partly  from  brown  or 
black  malt,  the  caramel  in  which  gives  it  the  sweetness  and  syrupy 
appearance,  and  containing  four  or  five  per  cent,  of  alcohol.  Stout  is  a 
stronger  porter,  with  larger  amount  of  dissolved  solids,  and  containing 
six  or  seven  per  cent,  of  alcohol. 

Lager-beer  is  beer  as  brewed  in  Germany  by  the  bottom  fermentation 
process,  which  process  is,  moreover,  retarded,  so  that  the  beer  has  better 
keeping  qualities.  It  also  has  a  larger  amount  of  hops  used  in  its  pro- 
duction. It  is  brewed  in  winter  for  storage  and  use  in  summer.  Schenk- 
beer  is  also  a  bottom  fermentation  beer,  but  is  designed  for  use  as  soon 
as  finished,  and  the  process  is  somewhat  quicker  than  with  lager-beer, 
and  a  smaller  amount  of  hops  is  used.  Bock-beer  is  a  stronger  lager- 
beer,  made  with  one-third  more  malt,  and  brewed  specially  in  the  spring 
of  the  year.  Weiss-beer,  as  before  stated,  is  made  chiefly  from  malted 
wheat,  and  is  yet  in  the  after-fermentation.  Most  other  names  are  from 
localities,  and  represent  the  characteristic  products  of  those  places. 

The  composition  of  various  English  and  German  beers  is  given  in  the 
accompanying  table  on  the  authority  of  Professor  Charles  Graham. 
(Allen,  Commercial  Organic  Analysis,  2d  ed.,  vol.  ii,  p.  92.) 


wd 

bio 

. 

•3 

<u 
I 

«> 

a 

•E 

2  so 
'0-3 

11 

a 

ig 

2 
1 

'3 
d 
o 

frt.-. 
c  ° 

§s 

s5 

0 

ja 

o 

3 

3 

M 

0> 

Q 

h 

jS.03 

a 

3 

o 

H 

<u 
a 
•< 

Sa 

OS  CJ 

1-1  9 

B 
< 

O  al 

|a 

M 

Burton  pale  ale    .  . 

1.75 

2.48 

0.21 

0.55 

5.13 

0.02 

0.14 

5.37 

1:1.05 

Burton  bitter  ale  .  . 

1.62 

2.60 

0.16 

0.87 

5.42 

0.01 

0.17 

5.44 

1:100 

Mild  X  ... 

1  87 

1  88 

020 

1  30 

539 

•^004 

014 

4  60 

1-085 

XXX     

288 

204 

030 

1  48 

680 

0.02 

0.10 

6.M 

1  :  0.96 

Scotch  export,  bitter 

1.62 

2.50 

0.30 

0.70 

5.21 

0.16 

0.09 

5.00 

1  :  0.96 

Dublin  stout,  XX    . 

3.45 

3.07 

0.26 

1.76 

8.71 

0.0  1 

0.17 

5.50 

1  :  0.63 

Dublin  stout,  XXX. 

535 

2.09 

0.43 

1.40 

9.52 

0.04 

0.25 

6.78 

1  :  0.71 

Vienna  lager  

1  64 

2  74 

0  36 

1  12 

590 

002 

013 

469 

1:078 

Pilsen  lager   ...... 

069 

2  65 

059 

4  22 

002 

009 

3.29 

1:0.80 

Munich  lager   

1  57 

3  15 

0  40 

1  82 

708 

001 

0.14 

4.75 

1  :  0.67 

MALT  LIQUORS. 


219 


The  composition  of  various  American  beers  and  ales  as  analyzed  by 
C.  A.  Crampton,  of  the  United  States  Department  of  Agriculture,  is  also 
given.* 


1 

9 

_ 

"3 

a 
1 

°o 

0 

1 

'3z3 

03  O 

a 

il 

o  § 

xtract. 

o 

a 

0 

o 

if 

3 

3 

-  —  1 

a> 

O 

.q 

M 

<< 

co  tao 

3 

B 

£ 

Put 

Milwaukee  lager,  bottled    .... 

1.10 

1.57 

0.51 

0.057 

0.196 

0.065 

4.18 

4.28 

1.0100 

Milwaukee  export  beer,  bottled  . 

1.06 

2.63 

0.40 

0.057 

0.309 

0.056 

5.40 

4.42 

1.0140 

Milwaukee  "Bohemian"  beer  .  . 

1.82 

3.04 

0.406 

0.071 

0.224 

0.057 

5.88 

4.16 

1.0183 

Milwaukee  "  Bavarian"  beer  .  . 

1.75 

2.87 

0.556 

0.074 

0.346 

0.077 

6.26 

5.06 

1.0187 

St.   Louis  export  beer     

214 

2.54 

0463 

0067 

0312 

0.074 

615 

440 

10178 

St.  Louis  pale  lager,  bottled  .  .  . 

2.17 

2.75 

0.463 

0.067 

0.312 

0.064 

4.64 

4.28 

1.0178 

St.  Louis  "  Erlanger"  beer,  bottled 

2.51 

2.58 

0.675 

.0.046 

0.183 

0.093 

6.82 

4.68 

1.0203 

Philadelphia  lager,  bottled        .   . 

1.46 

2.30 

0.538 

0.086 

0.241 

0.078 

5.22 

4.29 

1.0147 

Philadelphia  "  Budweiss,"  bottled 

2.14 

2.57 

0.531 

0.046 

0.265 

0.095 

5.94 

4.52 

1.0181 

Philadelphia  ale,  bottled    .... 

O.f.9 

0.90 

0.531 

0.232 

0.401 

0.085 

3.46 

6.24 

1.0059 

Reading  ale,  bottled  

0.93 

1.99 

0.731 

0.382 

0.472 

0.077 

5.55 

6.92 

1  0125 

Reading  porter,  bottled    

2.67 

2.88 

0.763 

0.166 

0.412 

0.100 

8.19 

4.89 

1.0269 

IV.  Analytical  Tests  and  Methods. 

1.  FOR  MALT. — The  brewing  value  of  a  sample  of  malt  is  dependent 
upon  three  factors, — namely,  the  proportion  of  soluble  or  extractive  matter 
it  will  yield  to  water;  the  character  of  this  extractive  matter;  and  the 
diastatic  activity.  The  extractive  matter  in  malt  is  usually  determined 
by  a  miniature  mashing  process.  This  is  carried  out,  according  to  the 
accepted  method  of  the  Institute  of  Brewing  in  England,  as  follows  :f 
The  malt  is  first  crushed  uniformly  fine ;  fifty  grammes  are  then  weighed 
out  as  rapidly  as  possible  (on  account  of  its  hygroscopic  character),  and 
placed  in  a  weighed  beaker  with  360  cubic  centimetres  of  distilled  water 
previously  heated  to  154°  to  155°  F.  The  beaker  is  covered  with  a 
watch-crystal  and  placed  in  a  water-bath  so  that  its  contents  are  kept  at 
a  temperature  of  150°  F.  for  fifty- five  minutes.  The  mash  is  stirred  at  in- 
tervals of  ten  minutes  during  this  time.  The  temperature  is  then  raised 
to  150°  F.  in  five  minutes,  and  the  whole  mash  washed  into  a  flask  grad- 
uated to  four  hundred  and  fifteen  cubic  centimetres,  cooled  to  60°  F., 
made  up  to  the  mark  at  the  same  temperature,  well  shaken,  and  filtered 
through  a  large  ribbed  paper.  The  specific  gravity  of  the  filtrate  is  then 
determined  at  once  at  60°  F.  compared  with  water  at  that  temperature. 
For  most  purposes,  it  is  sufficiently  accurate  to  make  up  the  unfiltered  wort 
to  four  hundred  and  fifteen  cubic  centimetres,  filter  a  portion  through  a 
dry  filter  and  take  the  density.  The  draff  is  here  assumed  to  measure 
fifteen  cubic  centimetres,,  and  the  tedious  washing  is  dispensed  with. 
The  excess  of  density  over  that  of  water  (taken  at  1000)  multiplied  by 
2.078  will  give  the  percentage  of  dry  extract  yielded  by  the  malt.  This 
method  is  based  on  the  fact  that  each  gramme  of  malt  extract  per  hun- 
dred cubic  centimetres  of  infusion  has  been  shown  by  experiment  to 
raise  the  density  of  the  liquor  by  3.85  degrees  (water  =  1000).  The 

*  United  States  Department  of  Agriculture,  Bulletin  No.  13,  Part  iii,  p.  282. 
t  Allen,  4th  ed.,  vol.  i,  p.  134. 


220  FERMENTATION  INDUSTRIES. 


figure  2.078  is  then  the  fraction    -^-^-    Instead  of  ascertaining  the 

o.oO 

gravity  of  the  infusion,  the  proportion  of  solid  matter  may  be  deter- 
mined by  evaporating  a  known  measure  of  the  wort  to  dryness  in  a  flat- 
bottomed  dish  so  that  the  residue  may  form  a  thin  film.  This  is  dried 
at  105°  C.  and  weighed.  Other  methods  are  those  of  Metz,*  with  the 
use  of  Schultze  's  tables,  and  of  Metz  as  improved  by  Weiss. 

The  determination  of  diastatic  power  in  a  sample  of  malt  is  also  of 
importance  in  valuing  it,  even  if  the  full  diastatic  power  is  not  likely  to 
be  called  out  in  the  brewing  process,  where  it  is  usually  in  excess  of  the 
need  for  the  production  of  a  beer-wort.  The  process  of  Lintner  adopted 
by  the  Institute  of  Brewing-j-  determines  by  the  aid  of  Fehling's  solution 
the  amount  of  maltose  produced  by  the  action  of  a  cold  infusion  of  the 
malt  upon  a  measured  starch  solution.  This  supposes  that  the  action 
of  diastase  upon  starch  in  the  cold  is  always  uniform  and  produces  the 
same  relative  amount  of  maltose,  which  is  now  regarded  as  a  matter  of 
some  uncertainty.  The  method  proposed  by  Dunstan  (Allen,  2d  ed., 
vol.  ii,  p.  278)  simply  notes  the  end  of  the  transformation  of  the  starch 
by  the  absence  of  color  with  iodine  solution.  For  it  five  grammes  of 
very  finely-powdered  malt  are  digested  and  agitated  for  one  hour  with 
fifty  cubic  centimetres  of  cold  water.  The  liquid  is  then  strained  off 
and  the  residue  again  digested  for  an  hour  with  fifty  cubic  centimetres 
of  water,  and  the  liquids  are  then  mixed  and  made  up  to  one  hundred 
cubic  centimetres.  Five-tenths  gramme  of  starch  (dried  at  100°  C. 
before  weighing)  is  gelatinized  by  boiling  with  water,  and  the  cold 
liquid  diluted  to  one  hundred  cubic  centimetres.  The  solution  of  malt 
extract  is  then  added  to  twenty  cubic  centimetres  of  this  mucilage  by 
instalments  of  one  cubic  centimetre,  at  intervals  of  half  an  hour,  until 
it  ceases  to  give  any  color,  when  a  small  quantity  is  tested  with  a  dilute 
solution  of  iodine.  If  less  than  one  cubic  centimetre  of  the  solution 
produces  this  effect,  more  of  the  mucilage  should  be  added  and  the 
operation  continued. 

To  determine  the  soluble  proteids  of  malt  assumed  to  represent  the 
diastase  C.  Graham  proposes  to  use  the  Wanklyn  albuminoid-ammonia 
process. 

2.  FOR  BEER-WORTS. — The  determination  of  the  specific  gravity  of 
the  wort  is  of  importance,  as  from  this  may  be  calculated  the  total  solid 
matter  in  the  wort.  If  from  the  specific  gravity  of  the  wort  we  take 
1000,  and  divide  the  difference  by  4,|  we  get  the  number  of  grammes 
of  solid  extract  contained  in  one  hundred  cubic  centimetres  of  the  wort. 
For  the  purpose  of  the  brewer  special  forms  of  hydrometers  have  been 
constructed,  the  readings  of  which  are  immediately  available.  Thus, 
Bates 's  saccharometer  gives  readings  of  pounds  per  barrel  (of  thirty- 
six  gallons), — that  is,  excess  of  weight  in  pounds  of  a  barrel  of  wort  over 
the  same  bulk  of  water.  These  readings  can  then  be  converted  into  real 

*  Stohmann  und  Kerl,  Technische  Chemie,  4th  ed.,  pp.  1345-1351. 

•j- Allen,  Com.  Org.  Analysis,  4th  ed.,  i,  p.  136. 

J  See  Allen,  Com.  Org.  Anal.,  4th  ed.,  vol.  i,  p.   140. 


MALT  LIQUORS.  221 

specific  gravity  figures  by  a  simple  proportion,  using  the  weight  of  a 
barrel  of  pure  water,  of  this  wort  with  the  excess  of  weight  shown  by  the 
saccharometer  reading  and  the  specific  gravity  of  pure  water  as  terms. 
The  Bates  saccharometer  readings  can  be  converted  into  those  of  Balling 

260  Bates 

or   Brix   by   the    following   formula:     Balling    —  OPA   ,   _.  ^     .      The 

ob(J  -\-  JhJates 

method  of  ascertaining  the  original  gravity  of  beer-worts  which  have 
undergone  fermentation  is  described  later.  (See  following  page.) 

In  brewing,  the  relative  proportion  of  maltose  and  dextrine  in  the 
wort  is  of  great  importance  and  is  liable  to  considerable  variation,  being 
dependent  on  the  temperature  at  which  the  mashing  was  conducted,  the 
length  of  time  occupied  in  the  process,  and  the  diastatic  activity  of  the 
malt  employed.  The  composition  of  the  wort  largely  influences  the  sub- 
sequent fermentation,  as  a  wort  containing  little  dextrine  will  produce 
a  beer  of  low  density  which  will  clarify  readily,  but  be  "thin"  and 
apparently  much  weaker  than  beer  of  the  same  original  gravity  but 
higher  final  attenuation.  C.  Graham  estimates  the  maltose  and  dextrine 
in  beer-worts  from  the  cupric  oxide  reducing  power  of  the  solution 
before  and  after  inversion.  (For  details  of  his  procedure,  see  Allen, 
vol.  ii,  p.  274.)  West  Knight  (Analyst,  vii,  p.  211)  has  described  a 
very  simple  and  rapid  method  of  approximately  determining  the  dex- 
trine in  beer-worts.  Ten  cubic  centimetres  of  the  wort  is  treated  in  a 
small  weighed  beaker  with  fifty  cubic  centimetres  of  methylated  spirit  of 
.830  specific  gravity.  This  causes  the  precipitation  of  the  greater  part 
of  the  dextrine,  which  after  a  few  hours  collects  on  the  bottom  of  the 
beaker  as  a  gummy  mass,  from  which  the  alcoholic  liquid  can  be  poured 
off.  The  deposit  is  rinsed  with  a  little  more  spirit,  and  the  beaker  dried 
in  the  water-oven  and  weighed.  To  the  weight  obtained  an  addition  of 
.045  gramme  is  made  as  a  correction  for  the  dextrine  retained  in  solu- 
tion by  the  spirituous  liquid. 

3.  FOR  BEER. — The  specific  gravity  of  the  beer  is  a  determination 
that  is  necessary  as  a  basis  of  calculation  for  the  other  determinations 
as  to  its  composition.  It  should  be  made  after  freeing  the  beer  from 
carbon  dioxide  as  fully  as  possible.  It  can  be  made  with  a  specific 
gravity  flask,  but  is  most  readily  and  accurately  carried  out  with  a 
Westphal  specific  gravity  balance  (see  Fig.  30),  which  for  this  purpose 
is  provided  with  a  fourth  rider  giving  the  fourth  place  of  decimals. 

The  amount  of  extract  is  frequently  determined  by  taking  a  definite 
volume  of  beer  of  which  the  specific  gravity  has  been  determined,  evap- 
orating it  to  one-third  its  bulk,  and  then  adding  water  sufficient  to  restore 
it  to  original  bulk.  The  specific  gravity  of  this  liquid  is  then  determined 
as  just  described.  The  percentage  of  extract  can  now  be  found  by  a 
reference  to  Schultze's  tables  for  determining  the  amount  of  extract  by 
specific  gravity,  or  more  simply  by  O 'Sullivan's  method,  in  which  the 
excess  of  this  specific  gravity  over  1000  divided  by  4  gives  the  number 
of  grammes  of  dry  extract  per  one  hundred  cubic  centimetres  of  the 
beer.  C.  Graham  considers  it  decidedly  more  accurate  to  evaporate  five 


222  FERMENTATION  INDUSTRIES. 

cubic  centimetres  of  the  beer  on  a  flat  watch-crystal  in  an  air-bath  at  a 
temperature  of  from  70°  to  75°  C.  The  complete  drying  of  the  film 
requires  about  twenty-six  hours. 

The  percentage  of  alcohol  is  best  determined  by  distillation.  For 
this  purpose  one  hundred  cubic  centimetres  of  the  beer  are  taken,  a  few 
drops  of  caustic  soda  added  to  neutralize  the  free  acid,  and  the  liquid 
brought  up  to  about  one  hundred  and  fifty  cubic  centimetres.  It  is  then 
distilled  with  the  aid  of  a  Liebig  condenser  into  a  graduated  flask  until 
nearly  one  hundred  cubic  centimetres  have  come  over.  The  distillate 
is  now  thoroughly  mixed,  cooled  to  15°  C.,  and  then  brought  exactly  to 
the  100-cubic-centimetre  mark  and  again  mixed.  Its  specific  gravity  is 
now  taken,  and  from  a  set  of  alcohol  tables  (see  Hehner's  tables,  Appen- 
dix, p.  579)  the  percentage  of  alcohol  by  weight  of  the  distillate  found. 
Then  as  the  specific  gravity  of  the  original  sample  is  to  the  specific 
gravity  of  the  distillate  so  is  the  weight  per  cent,  in  the  distillate  to  the 
weight  per  cent,  in  the  original  sample.  Indirectly  the  alcohol  percentage 
can  be  determined,  although  not  with  the  same  accuracy,  by  the  aid  of 
the  data  gotten  in  the  determination  of  extract  already  narrated.  For 
if  the  specific  gravity  of  the  original  sample  be  divided  by  the  specific 
gravity  of  the  de-alcoholized  solution  we  get  the  specific  gravity  of  the 
alcohol  driven  off,  from  which  figure  the  percentage  by  weight  of  alcohol 
can  be  gotten  in  the  tables.  When  both  the  alcohol  and  the  extract 
percentage  of  a  beer  are  known,  by  Balling's  method  the  percentage  of 
extract  in  the  original  wort  can  be  calculated,  and  then  with  the  aid  of 
this  and  the  percentage  of  extract  in  the  beer  the  "attenuation  "  or 
diminution  in  the  gravity  of  the  original  wort  due  to  fermentation  and 
alcohol  production  can  be  determined.  As  the  weight  of  alcohol  produced 
is  approximately  fifty  per  cent,  of  the  saccharine  matter  destroyed  by 
the  fermentation,  we  have  the  formula  2a  -(-  c  =  w,  in  which  a  is  the 
alcohol  percentage,  e  the  extract  percentage  of  the  beer,  and  w  the  per- 
centage strength  of  the  original  wort.  Then  using  this  figure  just 
obtained  w  :  100  : :  2a  :  x,  in  which  x  will  represent  the  degree  of  attenua- 
tion. More  accurately,  the  actual  degree  of  fermentation  (Wirklicher 
Vergdhrungsgrad)  is  gotten  by  the  proportion  p:p  —  n::WO:v',  in 
which  p  is  the  extract  in  the  original  wort,  n  the  extract  in  the  beer, 
and  v'  the  actual  fermentation  degree;  (p — n)  is  termed  the  "real  atten- 
uation." It  is  obvious  from  the  two  proportions  given  that  in  practice 
2a  is  often  taken  as  equivalent  to  (p  —  n).  This  is  not  strictly  correct. 
It  is  found  in  the  fermentation  of  beer-worts  that  100  parts  of  extract 
yield  48.391  parts  of  alcohol,  so  that  what  is  termed  an  "alcohol  factor  " 
is  necessary  to  convert  one  into  the  other.  In  England  a  different  pro- 
cedure is  followed.  A  definite  volume  of  beer  is  taken  and  one-half  dis- 
tilled off.  This  distillate  is  brought  up  with  water  at  60°  F.  to  the 
original  volume  and  its  specific  gravity  taken.  The  difference  between 
1000  and  the  observed  gravity  is  called  the  "spirit  indication  "  of  the 
beer.  With  this  can  be  found,  in  a  table  prepared  for  the  Inland  Reve- 
nue Office,  the  ' '  degrees  of  gravity  lost  ' '  by  the  attenuation  of  the  wort. 


THE  MANUFACTURE  OF  WINE.  223 

Then  the  liquid  left  in  the  retort  after  the  distillation  is  diluted  with 
water  and  brought  up  to  the  original  volume,  when  its  specific  gravity  is 
carefully  taken.  This  is  called  the  "extract  gravity,"  and  this  added  to 
the  degrees  of  gravity  lost  gives  the  ' '  original  gravity  of  the  wort. ' ' 

The  acidity  of  beer  is  partly  due  to  lactic  and  succinic  acids,  which 
are  fixed  acids,  and  partly  to  acetic  acid,  which  is  volatiie.  The  fixed 
acids  are  usually  determined  jointly  in  terms  of  lactic  acid  by  dissolving 
the  dry  extract  of  the  beer  in  water  and  titrating  the  solution  with  deci- 
normal  alkali  solution.  Baryta-water  is  preferred  by  many  chemists,  as 
the  sulphate  of  baryta  which  forms  carries  down  much  of  the  coloring 
and  allows  the  end  reaction  to  be  better  seen.  The  volatile  acid  of  beer 
is  chiefly  acetic  acid,  which  is  usually  determined  by  subtracting  the 
measure  of  alkali  required  to  neutralize  the  extract  from  that  required 
by  the  original  beer  (after  getting  rid  of  the  carbonic  acid  by  shaking 
thoroughly). 

The  chief  adulterations  of  beer  are  from  the  use  of  salicylic  acid  as  a 
preservative  and  the  addition  of  various  bitter  principles  as  substitutes 
for  hop-bitters.  The  salicylic  acid  may  be  searched  for  by  concentrating 
the  beer  to  one-half  at  a  gentle  heat  and  shaking  the  cooled  liquid  with 
ether,  or  a  mixture  of  ethylic  ether  and  petroleum-ether.  The  ethereal 
layer  is  then  separated,  evaporated  to  dryness,  and  the  residue  dissolved 
in  warm  water.  On  adding  ferric  chloride,  a  violet  coloration  is  pro- 
duced if  salicylic  acid  be  present.  Other  chemists  recommend  dialyzing, 
when  the  salicylic  acid  will  readily  dialyze  into  the  pure  water  and  can 
then  be  tested.  For  the  detection  of  the  bitter  principles  used  as  substi- 
tutes for  hops  elaborate  schemes  have  been  proposed  by  Enders  (given 
in  Allen,  4th  ed.,  vol.  i,  p.  162)  and  Dragendorff  (Gerichtliche-Chemische 
Ausmittelung  der  Gifte). 

C.     THE  MANUFACTURE  OF  WINE. 
I.  Raw  Materials. 

1.  THE  GRAPE. — While  the  name  wine  is  often  used  to  include  the 
products  of  the  spontaneous  alcoholic  fermentation  of  any  sweet  fruit  or 
berry,  it  is  usually  limited  to  the  product  of  the  fermentation  of  the 
grape,  which  alone  is  cultivated  on  an  extensive  scale  throughout  the 
civilized  world  purely  for  the  manufacture  of  wine. 

The  cultivation  of  the  grape-vine  and  the  production  of  wine  there- 
from dates  back  to  the  earliest  historic  times.  Beginning  in  the  East 
and  the  Mediterranean  lands,  it  extended  northward  and  westward  until 
at  present  France  is  the  chief  wine-producing  country,  while  Germany, 
Austria,  Spain,  and  Portugal  have  all  established  flourishing  wine  in- 
dustries indigenous  to  their  soil.  In  this  country,  the  wine  industry  is 
mainly  established  in  the  States  of  Ohio,  New  York,  Virginia,  and  Cali- 
fornia. 

The  varieties  of  the  vine  (estimated  to  number  almost  two  thousand) 
hitherto  cultivated  in  Europe  are  all  said  to  be  derived  from  the  single 


224  FERMENTATION  INDUSTRIES. 

species,  Vitis  vinifera.  In  this  country  four  or  five  wild  species  have 
yielded  varieties  which  when  cultivated  have  proven  adapted  to  wine 
production.  Thus  Vitis  riparia,  or  "  frost-grape, "  has  yielded  as  culti- 
vated varieties  the  Taylor  and  the  Clinton  grapes ;  the  Vitis  cestivalis,  or 
"summer-grape,"  has  yielded  as  varieties  Norton's  Virginia,  Cythiana, 
and  Herbemont;  the  Vitis  Labrusca,  or  "Northern  fox-grape,"  has 
yielded  as  varieties  the  Catawba,  Isabella,  Concord,  and  Delaware  grapes ; 
the  Vitis  vulpina  or  rotundifolia,  or  "Southern  muscadine,"  has  yielded 
as  varieties  the  black,  red,  and  white  Scuppernong.  Numerous  varieties 
of  the  European  vine,  the  Vitis  vinifera,  have  also  been  cultivated  suc- 
cessfully in  California,  among  which  may  be  mentioned  the  Mission, 
Riesling,  Trammer,  Rulander,  Gutedel,  and  Zinfandel. 

The  grapes  owe  their  wine-producing  value  in  the  first  place  to  the 
grape  (or  invert)  sugar  which  they  'contain,  and  in  the  second  place  to 
the  free  acids,  which  in  the  later  ripening  of  the  wine  are  to  develop 
the  fragrant  ethers,  and  to  the  albuminoids,  which  exert  a  great  influence 
on  the  fermentation.  The  composition  of  the  grape  varies  of  course  in 
different  localities  and  even  from  year  to  year  in  the  same  locality,  but 
its  mean  composition  is  thus  stated  by  Konig:  Grape-sugar,  14.36  per 
cent.;  free  acid  (tartaric),  .79  per  cent.;  nitrogenous  material,  .59  per 
cent. ;  non-nitrogenous  extract,  1.96  per  cent. ;  skins  and  kernel,  3.60  per 
cent. ;  ash,  .50  per  cent. ;  and  water,  78.17  per  cent. 

The  grapes  are  taken  for  wine-making  only  when  they  are  fully  ripe, 
and  in  many  localities  it  is  even  customary  to  wait  until  the  grape  shows 
a  slight  appearance  of  over-ripeness  or  evidence  of  wilting,  so  that  the 
maximum  of  sweetness  may  be  attained.  In  some  cases  the  grapes  are 
plucked  from  the  stems,  either  by  hand  or  by  the  aid  of  three-pronged 
forks,  while  in  other  cases  the  stems  are  left  when  they  are  crushed  in 
order  that  the  tannin  so  obtained  may  aid  in  the  clearing  of  the  ferment- 
ing juice.  This  juice  is  known  as  "must,"  and  the  pressed  pulp  and 
skins  as  the  "marc." 

2.  THE  MUST. — This  may  properly  be  considered  as  still  a  raw  mate- 
rial, as  its  expression  from  the  grapes  is  purely  a  mechanical  process. 
This  is  now  generally  effected  by.  power-presses  of  various  forms, 
although  at  one  time  largely  effected  by  trampling  the  grapes  under 
feet.  (This  method  is  still  followed  in  the  Oporto  and  the  Maderia  wine 
districts.)  The  first  portion  of  must  that  runs  from  the  presses  is  often 
collected  separately,  as  it  is  the  juice  of  the  ripest  and  sweetest  grapes; 
that  which  comes  later  is  richer  in  acid  and  in  tannin,  as  it  comes  partly 
from  unripe  grapes  and  partly  from  the  stems  and  skins.  The  amount 
of  must  that  is  obtained  usually  ranges  from  sixty  to  seventy  parts  in 
the  one  hundred  of  grapes. 

The  composition  of  this  must  is  of  the  greatest  importance,  as  upon 
it  depends  the  character  of  the  wine  that  will  be  produced,  whether  it 
shall  ferment  normally  throughout  and  develop  ^he  perfect  flavor  and 
aroma  desired,  or  whether  it  shall  be  thin  and  sour  and  show  tendencies 
towards  alteration  or  "disease."  The  proportions  of  its  constituents, 
especially  the  grape-sugar,  may  vary  within  quite  wide  limits  from  year 


THE  MANUFACTURE  OF  WINE. 


225 


to  year,  and  in  grapes  grown  in  the  same  year  under  different  conditions 
of  soil,  exposure,  etc. 

Thus,  two  different  musts  of  1868  are  given  and  two  musts  of  the 
same  variety  of  grape  in  two  succeeding  years,  the  first  of  which  was  a 
favorable  year  and  the  second  an  unfavorable  year.  The  analyses  are 
all  by  Neubauer. 


Sugar. 

Free 
acid. 

Albumi- 
noids. 

Ash. 

Non-nitro- 
genous 
extract. 

Water. 

Neroberger  Kiesling,  1868  
Steinbergcr  Auslese,  1868  

18.06 
24.24 

0.42 
0.43 

0.22 
0  18 

0.47 
0.45 

4.11 
3.92 

76.72 
70.78 

Hattenheimer,  1868,  (good  year)  .  .  . 
Hattenheimer,  1869,  (bad  year)  .  .  . 

23.56 
16.67 

0.46 
0.79 

0.19 
0.33 

0.44 
0.24 

5.43 
5.17 

69.92 
76.80 

The  percentage  of  grape-sugar  in  the  must  sinks  at  times  to  twelve 
per  cent.,  and  may  rise  as  high  as  twenty-six  to  thirty  per  cent.  The 
ratio  between  acid  and  sugar,  according  to  Fresenius,  ranges  from  1 : 29 
for  good  varieties  of  grapes  in  good  years  to  1 : 16  for  inferior  varieties 
in  medium  years.  If  the  ratio  falls  as  low  as  1 : 10,  the  grapes  are  un- 
ripe and  taste  acid.  This  ratio  of  acid  to  sugar  is  now  generally  taken 
as  the  criterion  for  the  quality  of  the  must  in  any  year  or  special  locality. 

In  bad  seasons  the  free  acid  is  more  generally  malic  than  tartaric, 
which  is  the  normal  constituent. 

n.  Processes  of  Manufacture. 

1.  FERMENTATION. — The  fermentation  of  the  must  is  a  spontaneous 
one  following  exposure  to  the  air,  and  due  to  the  spores  which  drop 
upon  the  surface  of  the  must  as  exposed  in  the  fermenting-tubs.  It  may 
be  a  surface  fermentation,  taking  place  at  temperatures  of  15°  to  20°  C., 
as  is  the  practice  in  Italy,  Spain,  and  the  south  of  France,  or  a  bottom 
fermentation,  taking  place  in  cooler  cellars  at  5°  to  12°  C.,  as  is  the 
practice  in  Germany  and  with  the  finer  French  wines.  The  first  method 
produces  a  fiery  wine  rich  in  alcohol,  but  without  bouquet  or  aroma ;  the 
second  method,  lighter  wines  with  delicate  bouquet,  due  to  the  formation 
of  wine  esters.  In  either  case  the  fermentation  can  be  divided,  as  was 
the  case  with  malt  liquors,  into  three  stages :  the  first,  or  main  fermenta- 
tion, which,  according  as  the  surface  or  the  bottom  fermentation  method 
is  followed,  lasts  from  three  to  eight  days,  or  from  two  to  four  weeks; 
the  second,  or  still  fermentation,  which  lasts  until  the  following  spring; 
and  the  third,  the  storage  fermentation,  which  lasts  for  several  years, 
until  by  the  gradual  development  of  its  bouquet  it  becomes  perfectly 
ripe. 

In  the  case  of  red  wines,  the  main  fermentation  is  allowed  to  take 
place  with  the  marc  added  to  the  must,  so  that  as  the  alcohol  is  developed 
it  may  dissolve  out  the  coloring  matter  (oenocyanin)  of  the  skins  as  well 
as  some  of  the  tannin,  which  latter  is  of  benefit  in  effecting  a  more  rapid 
separation  of  the  protein  materials.  To  prevent  this  pulpy  mass  from 
rising  to  the  surface  and  starting  a  souring  of  the  wine,  perforated 

15 


226  FERMENTATION  INDUSTRIES. 

covers  are  often  used  in  this  case  to  hold  it  down.  In  the  main  fermen- 
tation, the  casks  are  usually  freely  exposed  to  the  air.  Many  wine  ex- 
perts recommend  in  addition  the  aeration  of  the  fermenting  must  or  a 
whipping  of  the  liquid,  so  as  to  induce  a  fuller  and  more  vigorous  fer- 
mentation. On  the  other  hand,  other  authorities  consider  that  this  exces- 
sive exposure  to  air  injures  the  quality  and  aroma  of  the  wine,  and 
recommend  only  a  partial  exposure  to  the  air  after  the  main  fermenta- 
tion has  begun.  As  the  main  fermentation  comes  to  an  end,  the  yeast 
(with  more  or  less  tartar,  gummy  matter,  and  albuminoids)  settles  to 
the  bottom,  the  liquid  clears  and  is  ready  to  be  racked  off  into  casks, 
under  the  name  of  young  wine  (Jungwein),  to  undergo  the  after-  or  still- 
fermentation.  If  the  racking  off  does  not  take  place  promptly  with  the 
ending  of  the  more  energetic  main  fermentation,  the  young  wine,  of 
which  a  considerable  surface  is  exposed  to  the  air,  is  very  apt  to  start 
into  the  acetic  fermentation.  The  casks  into  which  it  is  now  put  are 
kept  quite  full  in  order  to  prevent  this  undesirable  change,  slight  addi- 
tions being  made  every  few  days  if  necessary,  and  the  bungs  are  set 
loosely  in  place.  During  this  after-fermentation  there  deposits  upon 
the  inner  walls  of  the  cask  argols,  or  impure  acid  potassium  tartrate 
(Weinstein),  with  some  yeast  and  albuminoid  matter.  This  fermenta- 
tion lasts  from  three  to  six  months,  and  then  the  wine  is  racked  off 
again  into  smaller  casks  to  undergo  the  final  ripening,  in  which  the 
bouquet  of  the  wine  is  especially  developed  by  the  formation  of  esters, 
while  it  clears  more  thoroughly  from  the  remaining  particles  of  yeast, 
etc.  The  duration  of  this  ripening  may  be  two,  four,  or  with  rich  wines 
even  eight  years  or  more,  when  it  is  considered  "bottle-ripe."  During 
this  ripening  fungous  vegetation  is  very  apt  to  start,  and  must  be 
arrested  in  order  to  prevent  the  spoiling  of  the  wine. 

2.  DISEASES  OF  WINES  AND  METHODS  OF  TREATING  AND  IMPROVING 
THEM. — The  souring  of  wine,  due  to  the  beginning  of  the  acetic  fermen- 
tation, is  one  of  the  commonest  of  these  so-called  diseases,  especially  with 
light  wines,  poor  in  alcohol  and  tannic  acid,  and  hence  commoner  with 
white  than  writh  red  wines.  It  arises  from  too  free  an  exposure  to  the 
air  and  too  high  a  temperature  during  fermentation.  If  just  begun  it  can 
be  cured  by  the  addition  of  a  small  quantity  of  potashes,  which  form 
potassium  acetate,  or  by  starting  the  alcoholic  fermentation  afresh  by 
adding  a  new  quantity  of  sugar.  If  the  souring  is  very  pronounced  it 
cannot  be  cured,  and  the  wine  is  made  into  wine-vinegar. 

The  gumminess  or  ropiness  of  wine  frequently  arises  from  a  prema- 
ture filling  into  bottles,  and  is  due  to  the  beginning  of  the  mucous  fer- 
mentation of  sugar.  It  takes  place  in  wines  poor  in  tannic  acid,  and 
hence  more  readily  with  white  than  with  red  wines.  It  can  be  cured  by 
addition  of  tannic  acid,  treatment  with  sulphurous  oxide,  or  starting  a 
new  fermentation  by  addition  of  grape-sugar. 

The  development  of  a  stale  or  flat  taste  in  tne  wine  is  due,  according 
to  Pasteur,  to  the  growth  of  a  thread-like  ferment.  The  wine  becomes 
cloudy,  diminishes  in  alcohol  and  increases  in  acid  percentage,  it  darkens 
in  color,  and  often  has  a  disagreeable  odor.  The  wine  is  racked  off  and 


THE  MANUFACTURE  OF  WINE.  227 

put  into  a  cask  which  has  been  filled  with  sulphurous  oxide  fumes,  which 
destroy  the  ferment. 

The  turning  bitter  of  red  wines  is  due  also,  according  to  Pasteur,  to 
a  plant-growth,  according  to  others  to  the  formation  of  a  bitter  aldehyde 
resin.  Neubauer  has  found  that  the  tannic  acid  and  the  coloring  matter 
both  decrease  in  percentage  in  this  disease.  It  can  be  cured  completely 
by  heating  the  wine  to  60°  to  64°  C.,  or  by  starting  the  fermentation 
anew  by  adding  fresh  quantities  of  grape-sugar. 

The  mouldiness  of  wine  is  due  to  the  development  of  a  fungoid 
growth  in  the  form  of  a  white  film  on  the  surface  of  wines  poor  in  alco- 
hol, and  always  precedes  the  souring  of  the  wine.  It  is  to  be  obviated  by 
treatment  with  sulphur  dioxide  or  more  effectual  protection  of  the  young 
wine  from  the  air. 

Of  the  general  lines  of  treatment  adopted  to  prevent  the  development 
of  these  various  diseases,  we  notice  first  the  clarifying  with  isinglass 
(finings)  or  other  form  of  gelatine.  This  is  particularly  applied  to  the 
sweet  and  heavy  white  wines,  which  often  remain  turbid  and  have  to  be 
cleared  by  the  coagulating  of  the  albuminoid  which  is  added.  With  red 
wines  which  contain  tannie  acid,  casein  or  blood  albumen  is  used  instead 
of  gelatine.  Fine  clays  are  also  used,  especially  in  Spain,  for  this 
clarifying. 

The  most  important  process,  however,  which  is  applied  for  the  pres- 
ervation and  protection  of  wine  against  diseases  is  that  known  as  "Pas- 
teurizing." It  consists  in  heating  the  wine  either  in  casks  or  in  bottles 
to  a  temperature  of  60°  C.,  and  then  preserving  it  without  exposure  to 
the  air.  This  temperature  is  found  to  be  sufficient  to  kill  most  of  the 
germs  which  bring  about  the  diseases  before  mentioned.  A  form  of  cask 
much  used  for  this  "Pasteurizing  "  process  is  shown  in  Fig.  60. 

The  use  of  salicylic  acid  for  preserving  wines  has  been  extensively 
tried,  but  its  use  here  is  open  to  the  same  objection  as  before  stated  in 
speaking  of  beer,  and  it  is  now  forbidden  in  most  countries. 

Of  the  methods  of  "improving  "  wines,  as  it  is  termed,  that  known 
as  "plastering  "  is  probably  most  largely  practised,  its  use  for  red 
wines  extending  to  Spain,  Portugal,  Italy,  and  the  South  of  France.  It 
consists  in  adding  plaster  of  Paris  (burnt  gypsum)  either  to  the  un- 
pressed  grapes  or  to  the  must.  The  plaster  takes  up  water  and  so  in- 
creases the  alcoholic  strength  of  the  fermenting  must,  which  in  turn 
allows  of  a  greater  extraction  of  the  coloring  matter  from  the  skin.  At  the 
same  time  the  wine  is  given  better  keeping  qualities  as  well  as  deeper  color. 
However,  the  sulphate  of  lime  changes  the  soluble  potash  salts  of  the 
wine  into  insoluble  tartrate  of  lime  and  soluble  acid  sulphate  of  potash, 
which  latter  remains  dissolved  along  with  some  of  the  gypsum,  and 
undoubtedly  has  an  injurious  effect  upon  the  consumers  of  the  wine. 
The  process  has  hence  had  to  be  controlled  by  law,  and  in  France  the 
sale  of  wine  containing  over  .2  per  cent,  of  potassium  sulphate  is  pro- 
hibited. The  ash  of  pure  wine  does  not  exceed  .3  per  cent.,  but  in  the 
samples  of  sherry  usually  met  with  it  reaches  .5  per  cent.,  and  is  almost 
entirely  composed  of  sulphates. 


228 


FERMENTATION  INDUSTRIES. 


Hugonneng  recommends  adding  diealcium  phosphate  instead  of  gyp- 
sum. This  process,  called  ' '  phosphotage, "  is  said  to  have  all  the  good 
effects  obtainable  from  plastering  without  increasing,  as  the  latter  does, 
the  percentage  of  sulphuric  acid  and  decreasing  that  of  phosphoric  acid. 

Chaptalization  consists  in  neutralizing  the  excess  of  acidity  in  the 
must  by  the  addition  of  marble-dust,  and  increasing  the  saccharine  con- 
tent by  the  addition  of  a  certain  quantity  of  cane-sugar,  which  the  vint- 
ners sometimes  replace  by  starch-sugar.  In  this  process  the  quantity  of 
the  wine  is  not  increased,  but  it  becomes  richer  in  alcohol,  poorer  in 
acid,  and  the  bouquet  is  not  injured.  It  is  much  used  in  Burgundy. 

Gallization,  as  proposed  by  Dr.  Gall,  has  for  its  object  the  bringing 
of  the  must  of  a  bad  year  up  to  the  standard  found  to  belong  to  a  good 

FIG.  60. 


must  (he  takes  as  standard  24  per  cent,  of  sugar,  .6  per  cent,  of  acid, 
and  75.4  per  cent,  of  water)  by  correcting  the  ratio  of  acid  to  sugar. 
This  he  does  by  adding  sugar  and  water  in  sufficient  quantity,  and 
tables  have  been  prepared  to  indicate  the  quantity  needed  according  to 
the  acid  ratio  shown  by  analysis.  In  both  these  processes,  starch-sugar 
ought  never  to  be  used  as  a  cheaper  substitute  for  cane-sugar,  as  com- 
mercial starch-sugar  will  always  introduce  dextrine,  an  entirely  foreign 
constituent,  into  the  must. 

Petiotization  is  a  process  which  takes  its  name  from  Petiot,  a  pro- 
prietor in  Burgundy,  and  is  carried  out  as  follows:  The  marc  from 
\vhich  the  juice  has  been  separated  as  usual  by  pressure  is  mixed  with  a 
solution  of  sugar  and  water  and  the  mixture  again  fermented,  the  second 
steeping  containing,  like  the  first,  notable  quantities  of  bitartrate  of  pot- 
ash, tannie  acid,  etc.,  which  are  far  from  being  exhausted  by  one  extrac- 
tion. The  process  may  be  repeated  several  times,  the  different  infusions 


THE  MANUFACTURE  OF  WINE.  229 

being  mixed.  This  process  is  very  largely  used  in  France,  and  is  said  to 
produce  wines  rich  in  alcohol,  of  as  good  bouquet  as  the  original  wine, 
and  of  good  keeping  qualities.  It  is  not  allowed  to  be  sold  there,  how- 
ever, as  natural  wine. 

Scheelization  consists  in  the  addition  of  glycerine  to  the  finished  wine 
so  as  to  improve  the  sweet  taste  without  injuring  its  keeping  qualities. 
The  limits  of  the  addition  of  glycerine  lie  between  one  and  three  litres 
to  the  hectolitre  of  wine.  If  the  wine  has  not  fully  fermented,  however, 
and  if  yeast-cells  are  present,  the  glycerine  may  yield  propionic  acid  by 
decomposition. 

3.  MANUFACTURE  OF  EFFERVESCING  WINES  (Champagnes}. — For  the 
manufacture  of  champagne  the  blue  sweet  grapes  are  preferred.     They 
must  be  pressed  promptly  after  picking  in  order  that  the  least  possible 
amount  of  color  be  taken  up  by  the  must.    The  first  pressing  only  is  used 
for  the  champagne,  and  a  second  pressing  of  the  marc  yields  a  reddish 
wine,  which  is  differently  utilized.     The  must  is  first  put  into  vats 
that  impurities  may  settle  and  then  filled  into  casks  for  the  main  fer- 
mentation, which  is  retarded  as  much  as  possible  by  being  carried  out  in 
cool  cellars.    Cognac  is  also  added  to  the  amount  of  about  one  per  cent., 
so  as  to  increase  the  alcohol  percentage  and  thus  moderate  the  fermen- 
tation.    After  the  main  fermentation  is  finished  the  wine  is  racked  off 
into  other  casks  and  left  stopped  until  winter  (end  of  December).    It  is 
then  fined   (or  cleared)   with  isinglass  and  transferred  to  other  casks, 
and  this  operation  is  repeated  in  a  month's  time.     Towards  the  begin- 
ning of  April  it  is  ready  to  be  transferred  to  bottles.     The  wines  of 
different  growths  are  now  mixed  and  the  amount  of  sugar  in  the  wine 
determined,  when  a  calculated  additional  quantity  is  added  in  the  form 
of  "liqueur"  (a  mixture  of  alcohol  and  pure  cane-sugar).     The  bottles 
which  are  to  receive  the  champagne  must  be  specially  chosen  and  be 
sufficiently  strong  to  stand  the  pressure,  which  rises  later  to  four  to  five 
atmospheres.     They  must  also  have  sloping  sides,  so  that  the  sediment 
may  not  adhere  to  ;the  sides  in  the  after-process.    The  wine  after  being 
corked  is  thoroughly  secured  by  an  iron  fastening  called  an  agrafe,  and 
the  bottles  are  arranged  in  piles  in  a  horizontal  position  in  the  large 
champagne-vaults,  where  they  remain  throughout  the  summer  months. 
Previous  to  the  wine  being  prepared  for  shipment,  the  bottles  are  placed 
in  a  slanting  position,  neck  downward,  in  frames,  and  the  incline  is 
gradually  increased  day  by  day  until  the  bottle  is  almost  perpendicular. 
With  the  sediment  thus  on  the  cork  it  goes  into  the  hands  of  a  workman 
called  a  "disgorger,"  who,  holding  the  bottle  still  neck  downward,  pro- 
ceeds to  liberate  the  cork  by  slipping  off  the  agrafe,  and  when  the  cork 
is  three-fourth  parts  out  he  quickly  inverts  the  bottle.    The  cork  is  thus 
forcibly  ejected  with  a  loud  report  by  the  froth,  which  carries  with  it 
the  greater  part  of  the  yeast  and  other  solid  matters,  what  remains  of 
these  being  got  rid  of  by  the  workman  working  his  finger  round  the  neck 
of  the  bottle,  whereby  they  are  detached  and  forced  out  by  the  still 
rising  froth.    The  wine  is  now  dosed  again  with  liqueur,  the  bottles  filled 
up,  wired,  and  the  neck  wrapped  with  foil  ready  for  shipment. 

4.  MANUFACTURE  OF  FORTIFIED,  MIXED,  AND  IMITATION  WINES. — All 


230 


FERMENTATION  INDUSTRIES. 


the  sweet  heavy  wines,  like  sherry,  malaga,  and  port,  are  characterized 
by  a  high  alcohol  percentage,  ranging  from  sixteen  to  twenty  or  twenty- 
two.  This  they  cannot  acquire  through  fermentation  alone,  as  twelve  or 
thirteen  per  cent,  seems  to  be  the  limit  of  alcohol  developed  in  a  wine  by 
direct  fermentation.  They  have  the  additional  alcohol  added  to  them 
directly  in  order  to  give  them  keeping  qualities.  With  some  sweet  wines 
the  alcohol  is  added  to  the  must  before  the  fermentation  in  order  that 
the  fermentation  shall  be  arrested,  while  a  certain  amount  of  sugar 
remains  in  the  wine  unchanged.  The  quality  of  wines  is  often  improved 
by  blending.  Light  wines  with  too  little  alcohol  are  mixed  with  stronger 
wines  with  the  formation  of  an  excellent  product  with  better  keeping 
qualities,  which  can  then  be  transported  to  long  distances  without  in- 
jury. These  mixtures  can  best  be  made  when  the  wines  are  new,  in 
order  that  after  mixing  they  may  undergo  an  insensible  fermentation 
and  take  a  character  distinctive  of  the  new  product. 

The  practice  of  adding  flavoring  substances  totally  foreign  to  the 
constituents  of  the  must  to  new  and  inferior  wines  in  order  that  they 
may  take  the  flavor  and  appearance  of  older  and  more  valuable  wine 
has  also  become  very  wide-spread.  Such  practices  are  of  course  illegal 
in  all  countries  where  laws  against  adulteration  are  enforced.  Thus, 
elder  flowers,  orris-root,  iris,  cloves,  oil  of  bitter  almonds,  and  numerous 
perfumes,  such  as  oil  of  orange  flowers,  of  neroli,  of  petit-grain,  and  of 
violet,  are  used,  as  well  as  coloring  infusions  like  raspberries  and  walnuts. 
The  heavy  wines  are  the  ones  most  generally  imitated.  Port  is  fre- 
quently flavored  with  a  mixture  of  elderberry  juice,  grape  juice,  brown 
sugar,  and  crude  brandy.  Sherry  often  consists  of  the  cheaper  Cape 
wine  mixed  with  honey,  bitter  almonds,  and  brandy.  In  Spain  and 
Southern  France  a  wine  prepared  from  the  vine  known  as  the  Teinturier 
and  possessing  an  intense  bluish-red  color  is  extensively  used  for  coloring 
of  other  wines. 

In  recent  years,  because  of  the  deficiency  in  the  wine  crop  of  France 
due  to  the  ravages  of  the  Phylloxera,  the  production  of  wine  from  dried 
raisins  or  prunes  has  enormously  increased.  This  product,  known  as 
' '  vin  de  raisin  sec, ' '  is  said  to  be  a  very  close  imitation  of  natural  French 
wines.  Spon  *  gives  the  following  as  the  components  of  such  a  raisin 
wine: 


White    sugar    5  kilos. 

Raisins    5  kilos. 

Common  salt    125  grammes. 

Tartaric  acid   200  grammes. 


Common   brandy    12  litres. 

River  water    95  litres. 

Gall-nuts    (bruised)    20 grammes. 

Brewer's  yeast   (in  paste)  .200  grammes. 


To  make  this  wine  of  a  red  color  it  is  necessary  only  to  add  to  the 
above  ingredients  two  hundred  and  fifty  to  three  hundred  grammes  of 
dry  picked  hollyhocks,  taking  care  to  keep  them  at  the  bottom  of  the 
cask.  N 

The  reports  of  the  United  States  consular  agents  show  that  the  man- 
ufacture of  this  raisin  wine  has  become  an  industry  of  large  propor- 
tions in  France  at  the  present  time.  A  significant  additional  indication 


*  Spon's  Encyclopedia  of  Industrial  Arts,  vol.  ii,  p.  444. 


THE  MANUFACTURE  OF  WINE.  231 

of  the  development  of  this  artificial  wine  industry  and  of  the  similar 
one  of  petiotizing  in  France  is  found  in  the  statement  of  the  amounts 
of  cane-sugar  used  by  French  wine  manufacturers  in  recent  years.  In 
1885  there  was  used  in  France  for  the  manufacture  of  grape  wines 
7,933,887  kilos,  of  cane-sugar;  in  1886,  27,856,592  kilos.;  for  the  man- 
ufacture of  fruit  wines  in  1885,  24,142  kilos,  of  sugar;  in  1886,  for  the 
same  purpose,  145,555  kilos.  Most  of  this  fruit  wine  forms  the  basis 
of  factitious  champagne, 

m.  Products. 

The  normal  constituents  of  a  natural  wine  agree  of  course  with  those 
contained  in  the  must,  except  in  so  far  as  new  compounds  have  been 
developed  by  the  fermentation  process  and  previously  existing  ones  have 
been  decomposed  or  made  to  separate  out. 

We  may  divide  the  constituents  of  wine  into  two  classes,  volatile  and 
fixed.  The  volatile  matters  are  as  follows :  Water  (eighty  to  ninety  per 
cent.)  ;  alcohol  (five  to  fifteen  per  cent.) ;  glycerine  (two  to  eight  per 
cent.)  ;  volatile  acids,  acetic,  cenanthic,  etc.,  constituting  one-fourth  to 
one-third  of  the  total  acidity;  aldehyde,  compound  ethers,  together  with 
other  fragrant  indefinite  constituents,  which  give  the  wine  its  flavor  and 
bouquet.  The  fixed  matters  are  glucose,  or  grape-sugar,  in  small  quan- 
tities in  most  wines ;  bitartrate  of  potash,  tartaric,  malic,  and  phosphoric 
acid,  partly  free  and  partly  combined  with  various  bases,  of  which  com- 
pounds phosphate  of  lime  is  the  most  abundant,  constituting  from 
twenty  to  sixty  per  cent,  of  the  weight  of  the  ash,  the  remainder  being 
chiefly  carbonate  of  potash,  resulting  from  the  calcination  of  the  bitar- 
trate, with  a  little  sulphate  and  traces  of  chlorides;  coloring  matters, 
pectin  and  analogous  gummy  matters;  tannin,  one  to  two  per  cent,  in 
red  wines  and  traces  only  existing  in  white  wines. 

No  very  simple  scheme  of  classification  is  possible,  as  the  methods 
and  products  of  most  countries  are  not  fixed  by  rule,  but  vary  widely 
according  to  the  season  and  market.  Still,  we  may  distinguish  between 
the  red  and  white,  and  the  sweet  and  the  dry,  wines;  between  the  light 
and  delicately-flavored  German  and  French  wines  and  the  more  fiery 
but  coarser  Italian  and  Swiss  wines;  between  natural  wines  and  those 
fortified  by  addition  of  alcohol,  as  port,  sherry,  and  madeira;  between 
still  wines  and  effervescing  or  champagne  wines. 

Most  of  these  terms  have  already  found  their  explanation  in  the 
description  of  the  processes  of  manufacture.  We  may  add  that  a  sweet 
wine  is  one  in  which  a  notable  portion  of  the  original  grape-sugar  of  the 
must  has  escaped  fermentation,  or  to  which  an  addition  of  sugar  has 
been  made  subsequent  to  the  main  fermentation.  A  dry  wine,  on  the 
contrary,  is  one  in  which  the  sugar,  whether  originally  present  or  sub- 
sequently added,  has  almost  all  undergone  change  in  the  processes  of  fer- 
mentation. Champagnes  are  wines  in  which  a  supplementary  fermen- 
tation is  purposely  developed  subsequent  to  the  bottling,  whereby 
quantities  of  carbon  dioxide  gas  are  developed  and  held  dissolved  under 
pressure.  On  opening  the  bottles  and  thus  relieving  the  pressure  a  brisk 
effervescence  follows,  due  to  the  escape  of  the  absorbed  gas.  Champagne- 


232 


FERMENTATION  INDUSTRIES. 


makers  distinguish  three  grades  of  effervescence.  In  mousseux  the 
pressure  in  the  bottles  amounts  to  from  four  to  four  and  a  half  atmos- 
pheres; in  grand  mousseux  it  reaches  five  atmospheres;  and  less  than 
four  atmospheres'  pressure  constitutes  cremant  (from  la  creme, 
"cream  "),  a  wine  which  throws  up  a  froth,  but  does  not  give  off  car- 
bonic acid  violently.  Some  manufacturers  also  distinguish  a  grade 
demi-mousseux. 

Of  natural   and  unfortified   foreign   wines   the   following   analyses 
from  Eisner  *  refer  to  German  wines  exclusively : 


o 

0 

««. 

o 

°.H 

£>£• 

bii^. 

f« 

fit 

If 

If 

°3  °* 

*    §  o 

"5  ti 

O  •£» 

s  «s 

0  0  t-> 

a  . 

li 

P—  >"3 

v  o> 

5  « 

02 

c 

CH 

A 

* 

A 

Rhine  wines,  Rudesheimer    .    .    . 

0.9960 

9.30 

1.97 

0.50 

0.20 

0.020 

"       Rauenthaler  .... 

0.9960 

9.25 

210 

0.54 

0.19 

0.023 

"         "      Johannisberger    .    . 

0.9958 

8.60 

2.20 

0.52 

0.19 

0.023 

"          "       Hochheimer  .... 

0.9935 

8.00 

1.50 

0.72 

0.16 

"          "       Niersteiner    .... 

0.9956 

7.54 

1.75 

0.62 

0.18 

6.012 

Moselle  wines,  Brauneberger  .   .    . 

2.60 

0.18 

0.041 

"          "       Pisporter  

2.40 

0.15 

0.038 

"          "       Zeltinger  

2.40 

0.16 

0.039 

Hessian  wines>  Bodenheimer  .   .    . 

0.9930 

7.54 

1.25 

6.63 

"          "       Laubenheimer  .    . 

0.9934 

6.83 

1.00 

0.60 

O.W 

"          "        Liebfrauenmilch   . 

0.9940 

8.00 

1.96 

0.62 

0.20 

'.   '.   '. 

Palatinate  wines,  Deidesheimer     . 

0.9968 

9.60 

2.12 

0.50 

0.18 

. 

"            "      Oppenheimer    . 

0.9935 

8.87 

1.50 

0.60 

0.16 

"            "      Wachenheimer  . 

0.9954 

8.65 

1.72 

0.65 

0.17 

Franconian  wines,  white    .... 

0.9943 

6.65 

1.20 

0.60 

0.015 

"              "      red     

0.9932 

8.00 

1.50 

0.47 

6.20 

The  following  analyses  of  French  wines  are  from  the  official  report 
of  the  Laboratoire  Municipal  at  Paris  for  1883 :  f 


GRAMMES  PER  LITRE. 

* 

a 

a 

fcc"""1 

1 

2 

|| 

1? 

g| 

ij 

m 

'3  oj  o 

'So 

.s  a 

M 

_o  ° 

t<3 

H  > 

^ 

|    "SSU 

3° 

'oW 

* 

H 

H 

^ 

H 

M 

02 

^ 

Bordeaux  wines,  St  Estephe  1878    

11.1 

10.3 

22.4 

19.0 

28.3 
23.7 

2.20 
2.05 

1.31 
1.42 

1.50 
0.9 

0.49 
0.76 

2.96 
3.% 

"       Medoc,  1880    

"       Latour,  1878       .  .             .... 

95 

170 

228 

2.14 

207 

1  1 

050 

4.06 

"       Chateau  Margaux,  1878  

10.2 

23.6 

1.5 

0.48 

"       Larose,  1877  

11.2 

23.0 

30.1 

2.34 

2.44 

1.3 

0.63 

(white,)  Sauterne,  1880   

10.4 

16.0 

3.6 

0.53 

Burgundy  wines,  Chambertin,  1882     

11.5 

23.3 

29.5 

1.77 

3.57 

1.4 

0.55 

.  . 

(white,)  Chablis,  1878  

11.0 

16.7 

.  . 

0.6 

0.38 

.  . 

Lower  Burgundy,  average  of  7  analyses  
Upper  Burgundy,  average  of  25  analyses  

7.8 
9.1 

20.2 
20.7 

•  •' 

1.2 
1.1 

0.37 
0.48 

'Praxis   des   Nahrungsmittels   Chemiker,    1880,   p.    103. 
fDeuxi£ine  Rapport  du   Laboratoire  Municipal,   Paris,    1884. 


THE  MANUFACTURE  OF  WINE. 


233 


Of  sweet  and  fortified  or  treated  wines  the  following  analyses  are 
given  by  Konig :  * 


OS 

<e  > 
'3g 
g& 

CO 

Alcohol  by 
weight. 

Extract. 

§ 

a 

CO 

Tartaric  acid. 

Glycerine. 

Albuminoids. 

JS 
< 

Phosphoric 
acid. 

Sulphuric 
acid. 

Tokay,  1868    

1.0879 

9.80 

26.36 

22.11 

0.509 

0.212 

0.427 

0.343 

0.050 

0.061 

Tokay,  Ausbruch,  1866  

10588 

10.29 

18.34 

14.99 

0.517 

0.234 

0.389 

0.300 

0.074 

0.022 

Ruster  Ausbruch  1872     

10849 

896 

23.64 

21.74 

0.512 

0.162 

0.231 

0.409 

0.057 

0.035 

Malaga,  1872  

10691 

1323 

21.23 

16.57 

0.416 

0.248 

0.217 

0.239 

0.042 

0.026 

Muscat  wine,  1872   

1.0574 

10.02 

16.91 

15.52 

0.555 

0.298 

0.151 

0312 

0.036 

0.073 

Port  wine  (white),  1860     

1.0126 

16.28 

8.83 

4.88 

0.538 

0.168 

0.094 

0.208 

0.035 

0.039 

Port  wine  (red)  1865  

1  0125 

17.93 

8.83 

6.42 

0.451 

0145 

0.200 

0.236 

0.032 

0.019 

Marsala  (Ingham)  

09966 

16.73 

4.94 

3.48 

0.396 

0.298 

0.150 

0.270 

0.024 

0087 

Marsala  (Woodhouse)  ....... 

10111 

1552 

545 

378 

0470 

0457 

0.231 

0.418 

0.024 

0.155 

Madeira,  1868    

1.0018 

15.34 

5.33 

3.39 

0.489 

0.291 

0.144 

0.376 

0.082 

0.081 

Sherry,  1870    

0.9952 

18.66 

3.78 

1.88 

0.438 

0.506 

0.200 

0.483 

0.032 

0.184 

Sherry,  Amontillado,  1870  

0.9924 

16.34 

2.68 

0.52 

0.490 

0.560 

0.200 

0.650 

0.038 

0.268 

Samos  wine.  1872  

1.0519 

10.97 

14.46 

11.82 

0.502 

0.237 

0.563 

0.058 

0.044 

Two  analyses  of  champagne  and  effervescing  wine  are  also  given  by 
Konig :  f 


2 
'3 

•S 

_ 

X!    • 

oS 

0 

o 

o^ 

•3  ft 

H 

•c 

_g 

o 
x:   . 

Si3 

03 

|M 

t? 

1 

1 

o 

XI 

4 

* 

°  S 

3* 

CO 

"" 

H 

CO 

O 

** 

PL, 

CO 

Champagne,  Carte  Blanche  .... 

1.0433 

9.51 

13.96 

11.53 

0.581 

0.084 

0.219 

0.134 

0.027 

0.017 

Effervescing  Rhine  wine    

1.0374 

9.80 

10.88 

849 

0566 

0  062 

0  294 

0  171 

0034 

0026 

Of  American  wines  a  large  number  have  been  investigated  by  the 
United  States  Bureau  of  Agriculture.  A  selection  from  those  analyzed 
by  H.  B.  Parsons  J  in  1880  is  given : 


9 

1 

S 

t>, 

!>, 

IS  • 

S 

i 

o» 

•—  '43 

•sa 

^j 

aj 

'a'c 

•  g 

<»  o 

<n'> 
'5  g 

js-SP 

2 

g 

8 

|| 

'"§* 

$  WJ 

rH   ^ 

r2  ^ 

"S 

"S 

I 

"o  « 

K  3 

"3  S 

CO 

^ 

^ 

w 

q 

o 

EH 

N 

Dry  red  wines  : 

Concord,  Virginia,  1879  

0.9953 

8.83 

11.08 

210 

0.174 

Trace. 

0.709 

0.452 

0.206 

Clinton,  Virginia,  1879    

0.9950 

9.82 

12.31 

2.36 

0^238 

None. 

0.784 

0.513 

(K217 

Norton's  Virginia,  1879  

09937 

1021 

1277 

288 

0298 

Trace. 

0772 

0377 

o!si6 

Ives's  Seedling,  Virginia,  1879    .... 

0.9944 

8.68 

10.82 

2.18 

0.'247 

Trace. 

0^723 

0.512 

o!l69 

Sonoma    Red    Mission,     California, 

1879  

0.9968 

7.99 

10.03 

2.42 

0.428 

None. 

0.722 

0.301 

0.337 

Sonoma   Red    Zinfandel,   California, 

1879  

09962 

780 

978 

243 

0  255 

Trace 

0693 

0391 

0  242 

Concord  Bouquet,  New  Jersey  .... 

0.9928 

9.84 

12.31 

2.18 

0.141 

0.71  ' 

0>41 

0'.272 

Oi375 

Nahrungs-  und  Genussmittel,  vol.  ii,  p.  463.  t  Ibid.,  p.  464. 

United  States  Bureau  of  Agriculture,  Bulletin  No.  13,  pp.  334-338. 


234 


FERMENTATION  INDUSTRIES. 


t*. 

O;" 

S> 

0  g 

&M 
02 

Alcohol  by 
weight. 

Alcohol  by 
volume. 

Extract. 

4 

<! 

Glucose. 

Total  acid  as 
tartaric. 

Fixed  acids  as 
tartaric. 

Volatile  acid  as 
acetic. 

Dry  white  wines  : 
Brocton  Catawba,  New  York  
Missouri  Catawba,  Missouri   
Ohio  Catawba,  Ohio    .  .  ,.  

0.9890 
O.U911 
0  98<J'> 

1228 
888 
1025 

15.30 
11.08 
1277 

2.09 
1.67 
1  63 

0.121 
0.129 
0  113 

Trace. 
Trace 

0.542 
0.772 
0  728 

0.470 
0.387 
0  424 

0.068 
0.308 
0  243 

Ruliinder,  Virginia,  1880  

09914 

1046 

1305 

190 

0  199 

0  545 

0  309 

0  194 

Delaware,  Virginia,  1880    

09932 

935 

11  70 

1  88 

0255 

0  562 

0  332 

0  184 

Taylor,  Virginia  1880     

0  9921 

1037 

1296 

1  99 

0  185 

Trace 

073'> 

0  317 

0  332 

Herbemont,  Virginia,  1880   

09928 

7  78 

9  80 

1  60 

0  146 

0  562 

0  302 

0  208 

Dry  Muscat,  California  
White  Zinfandel,  California    

0.9928 
0  9911 

9.14 
952 

11.44 
11  26 

1.8  > 
147 

0.150 
0  139 

Trace. 
Trace 

0.619 
0590 

0.248 
0227 

0.289 
0  290 

Riesling,  California    

09918 

964 

1205 

1  72 

0  921 

0696 

0  210 

0  389 

Gutedel,  California  

09920 

936 

11  70 

1  58 

0  196 

Trace 

0  726 

0212 

0  411 

Sonoma  Mission,  California,  1879  .  .  . 
Sweet  wines: 
Brocton  Port,  New  York      .      .  . 

0.9935 
1  0508 

8.30 
1000 

10.38 
1324 

1.67 

1704 

0.193 
0  139 

Trace. 
11  80 

0.619 
0828 

0.317 
0  600 

0.242 
0  182 

Speer's  Port,  New  Jersey  

1  0213 

1367 

1759 

1069 

0309 

744 

0705 

0  347 

0  286 

Port,  Los  Angeles,  California  .... 

1  0339 

1268 

1652 

14  18 

0  345 

11  39 

0508 

0348 

0  128 

New  York  Sherry     

1  0074 

1387 

1759 

683 

0  166 

484 

0689 

6.209 

0  323 

Speer's  Sherry,  New  Jersey  

09949 

1762 

2209 

4.89 

0219 

333 

0476 

0271 

0  164 

California  Sherry  

09942 

1342 

1680 

391 

0198 

220 

0573 

0  232 

0273 

Marsala,  California  ... 

1  0052 

1606 

20  33 

642 

0  428 

353 

06'>6 

0  418 

0  166 

"  Eclipse"  Extra  Dry  Champagne    . 
"  Gold  Seal"Champagne,  New  York 
Cook's  "  Imperial    Champagne     .  . 
Sweet  Catawba,  Bass  Island,  Ohio    . 
Sweet  Catawba,  Brocton,  New  York 
Sweet  Catawba,  Iowa,  1871  

1.0174 
1.0402 
1.0207 
10338 
1.0512 
1  0101 

9.26 
8.26 
8.41 
11.68 
1071 
989 

11.87 
10.82 
10.82 
15.21 
14.18 
1258 

7.78 
1331 
8.47 
14.49 
16.71 
723 

0.149 
0.110 
0.130 
0.152 
0.113 
0211 

6.51 
12.02 
7.23 
11.00 
15.22 
401 

0.885 
0.880 
0.779 
0.595 
0.714 
0668 

0.295 
0447 
0.470 
0.296 
0.471 
0  318 

0.472 
0.346 
0.247 
0.239 
0.194 
0280 

Sweet  Muscatel,  California  

10245 

1733 

1858 

81  34 

0371 

25.37 

0  753 

0421 

o  •'ee 

10440 

896 

11  79 

14.41 

0.196 

12.48 

0.489 

0310 

0143 

Brocton  Sweet  Regina      

10515 

971 

1287 

1652 

0101 

1531 

06r>8 

0465 

0  130 

Sweet  Delaware,  1879  

1  0320 

873 

11  35 

1207 

0118 

1027 

0799 

0  355 

0  355 

Scuppernong,  Sweet,  1878  

1  0404 

906 

1187 

1413 

0.132 

11  56 

0758 

03'>3 

0  348 

Scuppernong,  Dry,  1879  

0.9948 

1072 

13.43 

3.39 

0.108 

1.31 

0925 

0346 

0463 

Side-products. — The  first  of  these  is  the  marc  of  the  grapes,  sepa- 
rated from  the  must  in  the  original  pressing  of  the  grapes,  or  left  when 
the  fermenting  must  is  drained  from  it.  This  consists  of  the  stems, 
skins,  and  stones  of  the  grapes.  If  the  marc  instead  of  being  washed 
out  with  water  has  been  merely  pressed,  it  still  contains  sufficient  must 
to  allow  of  its  being  used  in  the  manufacture  of  petiotized  wine.  Be- 
sides this,  the  marc  serves  for  a  great  variety  of  purposes.  It  is  fer- 
mented for  brandy;  it  is  used  with  sheet-copper  in  the  manufacture  of 
verdigris;  it  is  used  to  start  the  fermentation  in  vinegar-making;  as 
cattle-food;  when  dried,  as  fuel  or  for  fertilizing  purposes;  the  tannic 
acid  is  extracted,  or  it  is  used  direct  in  producing  black  colors,  and  for 
other  minor  applications. 

The  second  and  more  valuable  side-product  is  the  deposit  formed  on 
the  bottom  and  sides  of  the  casks  in  which  the  fermentation  takes  place. 
That  on  the  bottom  of  the  casks  is  called  "lees."  It  contains  from  thirty 
to  forty  per  cent,  of  vegetable  matter  (from  the  yeast-cells  depositing), 
the  remainder  being  tartrates,  sulphates  (in  plastered  wines),  alumina, 
phosphoric  acid,  etc.  Its  composition  is  greatly  altered  by  "plastering  " 
the  wine,  in  which  case  the  tartrate  exists  chiefiV  as  the  neutral  calcium 
tartrate  instead  of  the  acid  potassium  salt.  The  crystalline  crust  that 
forms  on  the  sides  of  the  vessels  used  for  fermentation  is  called  "argol," 
or  crude  tartar.  It  varies  somewhat  in  composition,  the  tartaric  acid 


THE  MANUFACTURE  OF  WINE.  235 

ranging  from  forty  to  seventy  per  cent,  and  being  always  present, 
chiefly  as  the  acid  potassium  tartrate.  From  this  crude  tartar  is  pre- 
pared, by  extraction  with  boiling  water,  filtering,  and  crystallizing, 
"cream  of  tartar."  This,  however,  still  contains  some  calcium  tartrate 
mixed  with  the  acid  potassium  salt,  the  amount  ranging  from  two  to 
nine  per  cent. 

V.  Analytical  Tests  and  Methods. 

In  1884  the  Imperial  German  Health  Office  appointed  a  commission 
of  experts  to  report  upon  the  best  uniform  methods  for  the  analysis  of 
wines.  The  methods  agreed  upon  by  that  commission  are  very  generally 
adopted  now  in  Germany,  and  largely  used  elsewhere  in  guiding  wine 
analysts.  These  official  methods  have  been  fully  described  and  explained 
in  a  little  work  entitled  "Weinanalyse,"  by  Dr.  Max  Barth,  Leipzig, 
1884. 

The  specific  gravity  of  the  wine  is  determined  either  by  the  pyk- 
nometer  (specific  gravity  bottle)  or  by  the  Westphal  balance  (see  p. 
87),  the  readings  of  which  have  been  compared  with  those  of  the  specific 
gravity  bottle.  In  the  case  of  champagnes  and  effervescing  wines,  as 
was  the  case  with  beer,  the  carbonic  acid  must  be  got  rid  of  as  far  as 
possible  before  taking  the  specific  gravity  readings. 

The  alcohol  is  determined  by  the  direct  distillation,  as  described  on 
p.  222.  Wines  that  have  a  tendency  to  foam  have  a  little  tannin  (.1 
gramme)  added.  If  one  hundred  cubic  centimetres  of  the  sample  is 
taken,  sixty  cubic  centimetres  only  need  be  collected,  and  will  contain 
all  the  alcohol.  This  is  then  diluted  to  nearly  one  hundred  cubic  centi- 
metres, cooled,  uniformly  mixed,  and  then  brought  exactly  to  the  100- 
cubic  centimetre  mark,  mixed  again,  and  the  specific  gravity  taken.  The 
form  of  apparatus  best  adapted  for  this  determination  of  alcoholic 
strength  of  wines  and  liquors  is  shown  in  Fig.  61.  For  the  rapid  deter- 
mination of  the  alcoholic  strength  of  wines  various  forms  of  apparatus 
have  been  devised,  such  as  the  vaporimeter  of  Geissler,  in  which  the 
vapor-tension  of  an  alcoholic  liquid  exerted  upon  a  column  of  mercury 
is  made  to  indicate  its  percentage  strength  in  alcohol,  the  ebullioscope  of 
Tabarie,  of  Malligand  and  Vidal,  and  of  Amagat,  which  depend  upon 
the  observation  of  the  boiling-points  of  a  spirituous  liquor  as  determin- 
ing the  amount  of  alcohol  contained.  None  of  these  can  be  said  to  have 
scientific  accuracy,  as  wine  is  not  merely  a  mixture  of  alcohol  and  water, 
but  contains  other  constituents  which  affect  the  results  in  either  case. 

The  extract  detemi nation.  Here  the  direct  weighing  of  the  residue 
after  evaporation  is  preferred  to  the  indirect  method,  fifty  cubic  centi- 
metres of  the  wine,  measured  at  15°  C.,  are  to  be  evaporated  on  the 
water-bath  in  a  platinum  dish  (according  to  the  German  wine  commis- 
sion, this  dish  should  be  eighty-five  millimetres  in  diameter,  twenty 
millimetres  in  height,  seventy-five  cubic  centimetres  in  capacity,  and 
should  weigh  about  twenty  grammes),  and  the  residue  dried  for  two  and 
a  half  hours  in  a  double-walled  water  drying  oven.  In  the  case  of  wines 


236 


FERMENTATION  INDUSTRIES. 


containing  more  than  .5  per  cent,  sugar,  a  smaller  quantity  must  be 
taken  and  suitably  diluted,  so  that  the  extract  shall  not  weigh  more 
than  1.0  to  1.5  grammes.  In  this  method,  the  loss  of  glycerine  by  evap- 
oration is  trifling.  The  indirect  method  for  determining  the  extract  is 
very  like  that  described  under  beer  (see  p.  221)  as  0 'Sullivan's  method, 
except  that  with  wine  we  divide  the  excess  of  specific  gravity  observed 
over  1000  by  4.6  instead  of  4,  as  the  solids  of  wine  have  a  higher  solu- 
tion density  than  those  of  extract  of  malt.  Or  with  the  specific  gravity 
of  the  de-alcoholized  liquid  we  may  get  the  extract  percentage  from 
Hager  's  tables,  which  are  analogous  to  those  of  Schultze  for  malt  extracts 
before  referred  to. 

FIG.  61. 


The  ask  percentage  can  be  obtained  by  incineration  of  the  evaporated 
extract  above  referred  to. 

To  determine  the  percentage  of  glycerine,  one  hundred  cubic  centi- 
metres of  the  wine  are  evaporated  down  to  about  ten  cubic  centimetres 
in  a  spacious  porcelain  dish ;  some  sand  and  milk  of  lime  are  then  added 
till  the  reaction  is  strongly  alkaline  and  the  mixture  evaporated  almost 
to  dryness.  The  residue  is  next  treated  with  fifty  centimetres  of  ninety- 
six  per  cent,  alcohol,  warmed  and  stirred  on  the  water-bath,  and  the 
solution  obtained  then  passed  through  a  filter.  The  insoluble  matter  is 
washed  with  successive  small  portions  of  hot  alcohol  (ninety-six  per 
cent.),  of  which  fifty  to  one  hundred  and  fifty  cubic  centimetres  will  as 


THE  MANUFACTURE  OF  WINE.  237 

a  rule  suffice,  so  that  the  entire  filtrate  will  be  from  one  hundred  cubic 
centimetres  to  two  hundred  cubic  centimetres.  The  alcoholic  extract  is 
now  evaporated  to  a  viscous  consistency,  and  the  residue  taken  up  with 
ten  cubic  centimetres  of  absolute  alcohol;  this  solution  is  mixed  with 
fifteen  cubic  centimetres  of  ether  in  a  stoppered  flask  and  the  mixture 
allowed  to  stand  until  clear.  The  clear  liquid  is  decanted  or  filtered  into 
a  light  tared  glass  vessel,  carefully  evaporated,  and  the  residue  dried  for 
one  hour  in  the  water-bath.  It  is  then  cooled  and  weighed.  In  the  case 
of  sweet  wines  (containing  more  than  five  per  cent,  of  sugar),  only  fifty 
cubic  centimetres  of  the  wine  are  taken  for  the  estimation  of  the  gly- 
cerine ;  sand  and  lime  are  added,  and  the  mixture  is  warmed  on  the  water- 
bath.  After  cooling  it  is  treated  with  one  hundred  cubic  centimetres  of 
ninety-six  per  cent,  alcohol,  the  precipitate  formed  allowed  to  settle,  the 
solution  filtered,  the  insoluble  matter  washed  with  spirit,  and  the  alcoholic 
filtrate  treated  as  above  described. 

To  estimate  the  sugar  in  wine,  Fehling  's  solution  is  used,  as  the  sugar 
should  be  only  glucose.  After  neutralization  of  the  wine  with  sodium 
carbonate,  the  determination  is  made  (using  the  separately  preserved 
solutions  for  Fehling 's  mixture.  See  p.  175).  Strongly-colored  wines 
must  be  first  decolorized.  If  the  sugar  percentage  is  low,  it  is  done  with 
purified  bone-black ;  if  they  contain  over  .5  per  cent,  of  sugar,  bone-black 
cannot  be  used  because  of  its  absorptive  power,  and  basic  acetate  of  lead 
must  be  substituted.  After  filtering,  the  wine  is  then  treated  with  sodium 
carbonate  and  Fehling 's  solution.  If  the  polarization  indicates  the  pres- 
ence of  cane-sugar,  the  solution  must  be  inverted  (see  p.  174)  and  then 
the  Fehling 's  test  applied  again,  and  the  cane-sugar  calculated  from  the 
difference  in  the  two  readings.  The  Fehling 's  test  is  best  carried  out 
gravimetrically,  and  from  the  weight  of  reduced  copper  the  correspond- 
ing amount  of  glucose  can  be  obtained  from  the  tables. 

The  polarization,  which  is  essential  in  the  case  of  heavy  wines  to  indi- 
cate the  nature  of  the  sugar  contained,  is  carried  out  as  follows :  With 
white  wines,  to  sixty  cubic  centimetres  of  the  wine  are  added  three  cubic 
centimetres  of  the  basic  acetate  of  lead  solution  and  the  precipitate 
filtered  off  on  a  dry  filter.  To  31.5  of  the  filtrate  is  added  1.5  cubic  centi- 
metres of  a  saturated  solution  of  sodium  carbonate  and  the  solution 
again  filtered  and  the  polarization  tube  filled  with  the  filtrate.  The  dilu- 
tion of  the  original  wine  in  this  case  is  10 : 11.  With  red  wines,  sixty 
cubic  centimetres  of  the  wine  are  treated  with  six  cubic  centimetres  of 
the  lead  solution,  and  to  thirty-three  cubic  centimetres  of  the  filtrate 
three  cubic  centimetres  of  the  saturated  sodium  carbonate  solution  added, 
the  solution  filtered  and  polarized.  The  dilution  here  is  5:6.  This 
diluted  solution  is  observed  in  the  220-millimetre  tube  of  the  polariscope, 
and  large  and  accurate  instruments  are  necessary. 

The  free  acids  (total  acid-reacting  constituents  of  the  wine)  are 
estimated  in  twenty-five  cubic  centimetres  of  the  wine  heated  to  incipient 
boiling  by  means  of  one-tenth  normal  alkali.  Any  considerable  quantity 
of  carbonic  acid  to  be  first  removed  by  shaking.  The  ' '  free  acids "  to  be 
calculated  into  and  given  as  tartaric  acid  (C4H606). 


238  FERMENTATION  INDUSTRIES. 

The  volatile  acids  are  determined  by  steam  distillation  and  calculated 
as  acetic  acid  (C2H4O2). 

The  quantity  of  non-volatile  acids  calculated  as  tartaric  is  found  by 
subtracting  the  equivalent  of  the  acetic  acid  in  tartaric  acid  from  the 
free  acids  previously  determined. 

These  three  determinations  are  all  that  are  usually  made  in  wine 
analyses.  If  a  special  qualitative  test  for  free  tartaric  acid  is  desired  or, 
in  case  it  be  shown  to  be  present  in  appreciable  quantity,  a  quantitative 
method  for  its  determination,  they  can  be  made  by  Nessler's  method,  for 
details  of  which  the  reader  is  referred  to  Earth's  "Weinanalyse  "  before 
mentioned,  or  to  a  summary  of  its  methods  in  the  "Journal  of  the 
Society  of  Chemical  Industry,"  1885,  p.  553. 

The  tannin  may  be  determined  by  Neubauer's  method  with  perman- 
ganate of  potash,  or  approximately  by  the  following  procedure :  the  free 
acids  in  ten  cubic  centimetres  of  the  wine  are  neutralized  with  standard 
alkali,  after  which  one  cubic  centimetre  of  a  forty  per  cent,  solution  of 
sodium  acetate  is  added,  and  finally  a  ten  per  cent,  solution  of  ferric 
chloride,  drop  by  drop,  and  avoiding  excess.  One  drop  of  this  solution 
suffices  for  the  precipitation  of  every  .05  per  cent,  of  tannin. 

Salicylic  Acid. — To  detect  this  acid,  one  hundred  cubic  centimetres 
of  the  wine  are  shaken  repeatedly  with  chloroform,  the  latter  is  evap- 
orated, and  the  aqueous  solution  of  the  residue  tested  with  very  dilute 
ferric  chloride  solution.  For  the  purpose  of  an  approximate  quantita- 
tive estimation,  it  is  sufficient,  on  the  evaporation  of  the  chloroform,  to 
once  recrystallize  the  residue  from  chloroform  and  weigh  it. 

One  of  the  most  important  questions  that  arises  in  the  examination  of 
red  wines  is  as  to  the  genuineness  of  the  coloring  matter,  as  both  vege- 
table and  artificial  dye  colors  have  been  used  for  years  to  imitate  the 
natural  coloring  matter  in  the  manufacture  of  factitious  red  wines.  Very 
elaborate  schemes  for  the  recognition  of  foreign  coloring  matters,  includ- 
ing both  the  vegetable  coloring  matters  like  dye-woods  and  color-yielding 
berries  and  the  large  number  of  the  newer  coal-tar  colors,  have  been 
given  by  Gautier  *  and  by  Chas.  Girard,f  the  director  of  the  Laboratoire 
Municipal  in  Paris,  to  which  we  can  only  give  references.  The  coloring 
matters  most  generally  used  to  imitate  the  natural  pigment  of  the  grape- 
skins  are  fuchsine,  cochineal,  alder-berry,  hollyhock,  and  logwood.  Dupre 
tests  the  coloring  matter  as  follows:  Cubes  of  jelly  are  prepared  by  dis- 
solving one  part  of  gelatine  in  twenty  parts  of  hot  water  and  pouring 
the  solution  in  moulds  to  set.  These  are  immersed  in  the  wine  under 
examination  for  twenty-four  hours,  then  removed,  slightly  washed,  and 
examined.  Pure  wine  will  color  the  gelatine  only  very  superficially ;  the 
majority  of  other  coloring  matters  (fuchsine,  cochineal,  logwood,  Brazil- 
wood, litmus,  and  indigo)  penetrate  more  readily,  passing  to  the  very 
centre  of  the  cube.  The  double  dyeing  test  of  Sostegni  and  CarpentieriJ 
is  now  very  frequently  employed.  Take  one  hundred  cubic  centimetres 

*  Wynter  Blyth,  Foods,  Composition  and  Analysis,  p.  464. 

t  Deuxieme  Rapport  du  Laboratoire  Municipal,  p.  272. 

$  Bulletin  No.  107   (revised),  Bureau  of  Chem.,  U.  S.  Dept.  of  Agric.,  p.  190. 


MANUFACTURE  OF  DISTILLED  LIQUORS.  239 

of  the  wine,  acidify  with  from  two  to  four  cubic  centimetres  of  a  ten  per 
cent,  solution  of  hydrochloric  acid.  In  this  solution  immerse  a  piece  of 
woolen  cloth  which  has  been  washed  in  a  very  dilute  solution  of  boiling 
potassium  hydroxide  and  then  washed  in  water  and  boil  for  from  five  to 
ten  minutes.  Remove  the  cloth,  thoroughly  wash  it  in  water  and  boil 
in  a  very  dilute  hydrochloric  acid  solution.  After  washing  out  the  acid 
dissolve  the  color  in  a  solution  of  ammonium  hydroxide  (1:50).  Take 
the  wool  out,  add  a  slight  excess  of  hydrochloric  acid  to  the  solution, 
immerse  another  piece  of  wool  and  boil  it  again.  With  vegetable  color- 
ing matter,  such  as  the  wine  color,  this  second  dyeing  gives  practically 
no  color,  and  there  is  no  danger  of  mistaking  such  a  color  for  one  of 
coal-tar  origin  which  dyes  the  second  piece  of  wool  a  bright  shade.  This 
test  will  detect  minute  quantities  of  fuchsine  or  aniline  red.  The  fact 
that  pure  wine  color  is  not  changed  or  decolorized  by  nascent  hydrogen 
(zinc  and  acid),  while  most  of  the  aniline  dyes  are  decomposed  by  it,  is 
also  used  as  a  test. 

D.    MANUFACTURE  OF  DISTILLED  LIQUORS,  OR  ARDENT 

SPIRITS. 

This  industry  differs  radically  from  the  two  fermentation  industries 
already  described,  firstly,  in  that  the  effort  is  made  to  push  the  fermen- 
tation to  the  fullest  possible  limit,  so  that  the  maximum  quantity  of 
alcohol  may  be  produced,  and,  secondly,  in  that  this  product  of  fermen- 
tation is  then  distilled,  and  it  may  be  redistilled  in  order  to  get  a  dis- 
tillate richer  in  alcohol  than  the  fermentation  product  itself  can  be.  The 
end  to  be  attained  may  be  either  the  production  of  an  alcoholic  beverage 
as  the  product  of  distillation  or  of  raw  spirit,  which  takes  name  from 
the  material  used,  as  ' '  grain  spirit, "  "  potato  spirit, "  ' '  corn  spirit, ' '  etc. 
From  this  raw  spirit  by  the  processes  of  rectification  is  obtained  the 
"rectified  spirit  "  used  as  the  basis  of  the  manufacture  of  various  alco- 
holic beverages  and  as  a  solvent  in  various  manufacturing  processes,  and 
by  purification  and  dehydration  the  absolute  ethyl  alcohol  of  the  chemist. 

I.  Raw  Materials. 

These  may  be  divided  into  three  classes :  First,  alcoholic  liquids,  them- 
selves the  product  of  fermentation, — these  require  only  to  be  submitted 
to  distillation  in  order  to  yield  the  stronger  spirit ;  second,  solid  and  liquid 
materials  containing  some  variety  of  sugar,  whether  cane-sugar,  grape- 
sugar,  or  maltose,  which  are  directly  or  indirectly  fermentable;  and, 
third,  starch-containing  cereals  and  all  materials  capable  under  the  influ- 
ence of  diastase  or  dilute  acids  of  hydrolysis  and  the  production  of  a 
fermentable  sugar. 

1.  ALCOHOLIC  LIQUIDS  (Wines}. — The  distillation  of  wines  is  followed 
for  the  production  of  an  alcoholic  beverage  (brandy)  which  takes  to  some 
degree  its  flavor  and  bouquet  from  the  wines  used  in  the  distillation. 
"While  factitious  brandies  are  largely  made  from  grain  or  potato  spirit, 
the  true  product  from  wine  is  always  regarded  as  superior. 


240  FERMENTATION  INDUSTRIES. 

The  manufacture  of  wine  brandy  has  been  chiefly  carried  out  in 
France,  and  in  minor  degree  in  Spain  and  Portugal.  Within  recent 
years  California  wines  have  also  been  used  for  the  manufacture  of 
brandies.  The  French  wines  which  are  used  are  largely  those  of  the 
departments  Charente  and  Charente-Inferieure,  in  the  southwest  of 
France,  and  the  product  is  all  known  as  Cognac  brandy. 

White  wines  are  said  to  yield  a  superior  spirit  to  that  obtained  from 
red  wines,  and  older  wines  better  than  newer  ones.  About  eight  and  a 
half  hectolitres  of  wine  are  needed  to  produce  one  hectolitre  of  brandy. 
Because  of  the  ravages  of  the  Phylloxera  insect,  the  manufacture  of 
genuine  wine  Cognac  has  decreased  enormously  in  France  in  recent 
years,  while  the  manufacture  of  factitious  Cognac  has  correspondingly 
increased.  Thus  we  find  it  officially  stated  *  that  the  production  of 
alcohol  from  wine  in  France  had  decreased  from  530,000  hectolitres  in 
1875  to  14,678  hectolitres  in  1883. 

The  marc  of  the  grapes,  as  already  stated  (see  p.  234),  is  also  utilized 
in  the  manufacture  of  an  inferior  grade  of  brandy,  known  in  France  as 
eau  de  vie  de  marc.  The  lees,  or  sediment,  of  the  wine-casks  are  also 
used  in  this  same  way.  This  brandy  is  not  necessarily  sold  for  consump- 
tion, but  is  used  to  strengthen  the  alcoholic  percentage  of  wines  in  which 
fermentation  is  to  be  arrested. 

2.  SUGAR-CONTAINING  RAW  MATERIALS.— The  most  important  sugar- 
yielding  materials  cultivated  on  a  large  scale,  it  will  be  remembered,  are 
the  sugar-cane  and  the  sugar-beet.    The  sugar-canes  are  not  used  directly 
for  the  production  of  spirits  (except  in  the  case  of  accidental  souring), 
and  the  "bagasse,"  although  still  containing  saccharine  juice,  is  too 
bulky,  and  hence  is  at  once  burned  as  fuel,  but  the  molasses  obtained  on 
so  large  a  scale  in  the  extraction  of  raw  sugar  is  a  most  valuable  material 
for  the  purpose.    Throughout  both  the  West  Indies  and  the  East  Indies 
enormous  quantities  of  this  molasses  are  fermented  and  the  resultant 
product  distilled  for  rum.    Even  the  sugar  scums  obtained  in  the  defe- 
cating and  concentrating  of  the  sugar  juice  are  fermented,  and  produce 
an  inferior  grade  of  rum. 

With  the  sugar-beet,  both  the  beet  itself  and  the  beet-molasses  are  util- 
ized, the  former  being  used  in  France  and  the  latter  in  both  France  and 
Germany.  Sweet  fruits,  the  juice  of  which  is  rich  in  sugar,  also  serve  as 
raw  materials  for  the  spirit  industry.  Thus  peaches,  plums,  and  cherries 
are  much  used  in  different  countries  for  the  manufacture  of  fruit  brandy, 
and  the  fermented  juice  of  the  date-palm  in  the  East  Indies  and  of  the 
plantain  in  the  West  Indies  both  serve  for  the  distillation  of  an  alcoholic 
beverage. 

3.  STARCH-CONTAINING  RAW  MATERIALS. — This  list  includes  the  main 
sources  for  the  distillation  of  spirits,  as  the  high  percentage  of  starch  in 
many  cereals,  ranging  from  sixty  to  seventy-seven  per  cent.,  the  ease  with 
which  the  starch  can  be  converted  into  fermentable  sugar  under  the  in- 
fluence of  diastase  or  dilute  acids,  and  the  cheapness  of  these  starchy 
products  of  nature  all  combine  to  make  them  for  most  countries  the 

*  Deuxi&me  Rapport  du  Laboratorie  Municipal,   p.  272. 


MANUFACTURE  OF  DISTILLED  LIQUORS.  241 

cheapest  and  best  materials  for  the  spirit  industry.  In  the  United  States, 
the  three  cereals  used  almost  exclusively  for  the  manufacture  of  distilled 
liquors  are  corn,  rye,  and  malted  barley;  in  England,  barley,  both  raw 
and  malted,  rye,  corn,  and  rice ;  in  Germany  the  potato  is  almost  the  only 
starchy  material  used.  The  composition  of  the  several  cereals  showing 
their  relative  percentage  of  starch  was  given  on  p.  186. 

n.  Processes  of  Manufacture. 

1.  PREPARATION  OF  THE  WORT. — In  England  and  the  United  States, 
where  grain  spirit  is  mainly  manufactured,  the  first  process  is  that  of 
saccharifying  the  starch  of  the  grain.  In  the  special  cases  where  malted 
grain  alone  is  used,  the  mash  process  somewhat  resembles  that  already 
described  under  beer-brewing.  Most  distillers,  however,  use  mixtures  of 
raw  and  malted  grain,  in  which  the  raw  largely  predominates,  being  often 
ten  to  one  or  even  more,  as  a  very  small  quantity  of  diastase  can  be  made 
to  convert  a  large  amount  of  starch  into  maltose  or  fermentable  sugar. 
It  is  stated,  moreover,  that  the  yield  of  spirit  is  larger  when  several  kinds 
of  grain  are  mixed  than  when  one  kind  is  used  singly.  The  mixture  of 
raw  and  malted  grain,  properly  ground,  is  put  into  the  mash-tub  (see 
Fig.  59,  p.  214)  with  water  at  150°  F.  and  agitated.  This  first  mashing 
requires  from  one  to  four  hours,  the  larger  the  quantity  of  raw  grain  used 
the  longer  being  the  time  required  for  mashing.  The  temperature  of  the 
mixture  is  kept  up  to  about  145°  F.  by  the  successive  additions  of  water 
at  a  somewhat  higher  temperature  (190°  to  200°  F.).  The  object  of  the 
distiller  in  this  is  somewhat  different  from  that  of  the  beer-brewer.  He 
wishes  to  convert  the  whole  of  the  starch,  if  possible,  into  maltose,  which 
is  directly  fermentable  by  the  action  of  yeast,  while  the  dextrine  is  not, 
so  he  must  mash  at  not  much  over  146°,  which  it  will  be  seen  from  Fig. 
58  (p.  207)  is  the  limit  above  which  the  maltose  production  begins  to 
decrease.  When  the  gelatinization  of  the  starch  is  complete,  the  tem- 
perature of  the  mash  may  go  slightly  higher.  By  keeping  within  this 
limit  of  temperature,  a  minimum  of  diastase  from  the  small  admixture 
of  malt  will  gradually  change  not  only  the  starch,  but  bring  about  a 
hydration  of  the  residual  dextrine,  converting  it  into  maltose.  When 
the  wort  has  acquired  its  maximum  density,  as  found  by  the  saccharo- 
meter,  it  is  drawn  off,  and  fresh  water  at  about  190°  F.  is  run  upon  the 
residue  in  the  mash-tub  and  allowed  to  infuse  with  it  for  one  or  two 
hours.  This  second  wort  is  then  added  to  the  first.  A  third  weak  wort 
is  often  obtained,  and  used  to  infuse  new  lots  of  grain.  The  mash  is  then 
cooled  down  promptly  to  the  temperature  required  for  fermentation  so 
that  the  acetous  fermentation  may  not  set  in. 

It  is  stated  that  in  this  method  of  open-tub  mashing  ten  per  cent,  of 
the  starch  escapes  decomposition,  even  although  the  grain  may  be  taken 
finely  ground.  Hence  a  preliminary  warming  with  water  to  which  a  little 
green  malt  is  sometimes  added,  followed  by  heating  with  water  under  a 
pressure  of  several  atmospheres,  now  often  precedes  the  addition  of  the 
main  quantity  of  the  malt,  which  is  to  complete  the  conversion  of  the 

16 


242  FERMENTATION  INDUSTRIES. 

starch  and  dextrine  into  maltose.  This  treatment  is  carried  out  in  so- 
called  "vacuum  cookers." 

In  Germany  potatoes  constitute  the  chief  raw  material  for  the  spirit 
manufacture.  They  contain  from  eighteen  to  twenty  per  cent,  of  starch 
only,  however,  while  the  cereals  contain  over  sixty  per  cent.  The  amount 
of  the  malt  needed  for  the  saccharification  of  the  starch  can  therefore  be 
correspondingly  reduced.  Instead  of  mashing  the  ground,  rasped,  or 
chipped  potatoes  in  open  mash-tubs  as  was  formerly  done,  they  are  now 
first  steamed  under  a  pressure  of  two  to  three  atmospheres,  whereby  the 
starch-containing  cells  are  thoroughly  ruptured  and  the  starch  put  in 
condition  to  be  easily  acted  upon  by  the  diastase.  Among  the  forms  of 
apparatus  based  upon  this  principle  may  be  mentioned  those  of  Holle- 
freund,  Bohm,  Henze,  and  Ellenberger.  In  that  of  Henze,  which  has 
been  largely  adopted,  the  potatoes,  after  steaming  under  a  pressure  of 
several  atmospheres,  are  so  disintegrated  that  on  opening  a  valve  in  the 
bottom  of  the  vessel  the  pulp  is  forced  out  through  a  grating  in  a  thin 
stream.  This  is  cooled,  mixed  with  the  requisite  quantity  of  malt,  and 
started  to  mashing.  In  the  Hollefreund  and  in  the  Bohm  cookers,  the 
steaming,  disintegrating,  and  mashing  all  take  place  in  the  same  closed 
vessel,  the  malt  being  added  after  the  disintegrated  mass  has  been  prop- 
erly cooled  down.  Green  malt  is  found  to  work  better  in  this  case  than 
air  malt,  and  produces  more  alcohol. 

2.  FERMENTATION  OP  THE  WORT,  OR  SACCHARINE  LIQUID. — In  the  case 
of  mashing,  as  described  above,  either  with  grain  or  with  potatoes,  the 
wort  must  first  be  cooled  down  before  adding  the  yeast  and  starting  the 
fermentation.  The  yeast  used  is  a  surface  yeast,  and  either  fresh 
brewer's  yeast  or  compressed  yeast  (previously  softened  in  warm  water) 
may  be  used.  The  procedure  is  now  somewhat  different,  according  as 
we  have  a  grain-mash  or  a  potato-mash  to  deal  with.  In  the  former  case, 
using  a  thin  wort  drained  from  the  exhausted  grain,  it  has  been  found 
that  the  best  results  are  obtained  when  the  temperature  during  fermen- 
tation rises  to  about  33°  or  34°  C.  (92°  to  94°  P.),  as  shown  in  Fig.  58 
(see  p.  207)  ;  in  the  latter  case,  where  the  entire  mash,  solid  matter  and 
all,  is  fermented,  the  fermentation  begins  at  a  much  lower  temperature, 
and  the  heat  evolved  in  the  fermentation  of  such  a  concentrated  wort 
ultimately  carries  the  temperature  to  the  same  maximum.  In  the  English 
plan,  considerable  lactic  acid  forms  because  of  the  higher  temperature, 
and  this  constitutes  a  sour  yeast  mash,  while  in  the  German  plan,  because 
of  the  low  initial  temperature  of  the  fermentation,  comparatively  little 
lactic  acid  is  produced,  and  when  the  higher  temperatures  are  reached 
the  mixture  already  contains  so  much  alcohol  that  the  lactic  acid  ferment 
grows  with  considerable  difficulty. 

For  one  thousand  litres  of  grain-mash,  eight  to  ten  litres  of  brewer's 
yeast  or  one-half  kilo,  of  compressed  yeast  are  used;  for  one  hundred 
litres  of  potato-mash,  one  to  two  litres  of  brewer's  yeast  or  three-fourths 
to  one  kilo,  of  compressed  yeast  are  needed. 

The  fermentation  is  sometimes  divided  into  several  stages:  the  pre- 
liminary fermentation,  in  which  the  yeast-cells  grow  without  much  alco- 


MANUFACTURE  OF  DISTILLED  LIQUORS.  243 

hoi  formation ;  the  main  fermentation,  in  which  the  maltose  is  fermented ; 
and  the  a/^er-treatment,  in  which  the  dextrine  is  gradually  changed  into 
maltose  and  this  into  alcohol. 

The  time  of  fermentation  varies  from  three  to  nine  days,  but  it  is  car- 
ried on  until  the  density  of  the  liquid  ceases  to  lessen  or  attenuate,  which 
is  determined  by  the  saccharometer. 

The  coefficient  of  purity  of  a  fermentation  is  a  term  used  to  designate 
what  percentage  of  the  available  starchy  material  in  a  substance  has 
actually  undergone  the  pure  alcoholic  fermentation.  Thus,  the  reaction 
C0H1005  -(-  H20  =  2C2H60  -f-  2C02  demands  from  one  kilogramme  of 
starch  a  percentage  of  alcohol  equal  to  71.7  litres,  and  such  a  yield  from 
one  kilogramme  of  fermented  material  would  indicate  a  purity  coefficient 
of  one  hundred  per  cent.  A  percentage  yield  equal  to  sixty  litres  of 
alcohol  from  one  kilo,  of  material  would  give  a  purity  coefficient  of  83.7 
per  cent. 

The  use  of  hydrofluoric  acid  or  ammonium  fluoride,  first  proposed  by 
Effront  as  an  antiseptic  and  indirect  aid  to  the  alcoholic  fermentation, 
has  become  quite  important  in  the  spirit  industry.  The  advantages 
claimed  for  its  use  are :  first,  by  preventing  the  losses  due  to  secondary 
fermentation,  the  alcohol  yield  is  increased;  second,  this  yield  is  espe- 
cially maintained  when  raw  materials  of  somewhat  inferior  quality  are 
used,  when  without  the  hydrofluoric  acid  the  yield  would  be  diminished ; 
third,  the  development  of  foaming  in  the  fermentation  is  in  large  degree 
prevented. 

In  France,  the  juice  from  inferior  beets  instead  of  being  worked  for 
the  extraction  of  sugar  is  often  fermented  and  distilled.  The  juice  is 
made  slightly  acid  with  sulphuric  acid  to  prevent  any  viscous  fermen- 
tation, and  a  small  quantity  of  brewer's  yeast  is  added.  The  tempera- 
ture of  the  fermentation  is  from  20°  to  22°  C.,  and  the  process  is  usually 
complete  in  from  twenty-four  to  thirty-six  hours. 

The  use  of  the  molasses  obtained  in  the  extraction  of  the  raw  sugar, 
whether  from  the  sugar-beet  or  the  sugar-cane,  is,  however,  much  more 
common.  In  France  and  Germany,  where  the  beet-sugar  molasses  is  pro- 
duced in  large  quantities,  the  molasses  originally  marking  40°  to  48° 
Beaume  is  diluted  to  8°  or  10°  Beaume,  and  sulphuric  acid  of  66°  is 
added  to  the  amount  of  1.5  per  cent,  of  the  molasses  taken.  This  neu- 
tralizes the  bases  of  the  beet-molasses  and  inverts  the  cane-sugar  present, 
bringing  it  into  fermentable  form.  Brewer's  yeast  is  then  added,  and 
the  fermentation  proceeds  rapidly.  The  temperature  ranges  from  22°  C., 
that  usually  chosen  in  France,  where  more  dilute  solutions  are  fermented, 
to  25°  to  30°  C.  in  Germany,  where  the  concentration  is  usually  as  much 
as  12°  B.  Two  hundredweight  of  molasses  at  42°  B.  will  furnish  about 
six  gallons  of  pure  spirit. 

In  the  West  Indies,  notably  in  Jamaica,  the  cane-sugar  molasses  is 
similarly  utilized,  but  the  procedure  is  somewhat  different.  In  this  case 
the  addition  of  yeast  is  unnecessary,  as  the  nitrogenous  matters  present 
suffice  to  start  spontaneous  fermentation.  The  best  rum  is  that  gotten 
from  the  molasses  alone ;  a  second  grade  is  obtained  from  the  skimmings 


244  FERMENTATION  INDUSTRIES. 

and  "sweet-waters  "  which  accumulate  in  the  extraction  of  the  sugar. 
To  these  is  added  some  "dunder  "  (fermented  wash,  deprived  by  dis- 
tillation of  its  alcohol  and  much  concentrated  by  boiling),  which  acts  as 
the  ferment  and  starts  the  action.  Molasses  is  then  added  in  the  pro- 
portion of  six  gallons  to  every  hundred  gallons  of  the  fermenting  liquid 
and  the  action  allowed  to  go  to  completion.  One  hundred  gallons  of  this 
mixture  when  distilled  should  yield  twenty-five  gallons  of  "low  wines  " 
or  one  gallon  of  proof  rum  for  each  gallon  of  molasses  employed. 

3:  DISTILLATION  OF  THE  FERMENTED  MASH,  OR  ALCOHOLIC  LIQUID. — 
Upon  the  construction  of  apparatus  for  the  distilling  from  the  fermented 
mash  of  the  alcohol  which  it  contains  much  skill  and  ingenuity  have  been 
displayed,  and  some  of  the  later  forms  of  stills  and  rectifying  apparatus 
employed  in  large  distilleries  are  wonderfully  adapted  for  obtaining  in 
a  continuous  operation  the  purest  and  strongest  alcohol  from  the  crude 
fermentation  products.  We  may  distinguish  some  five  main  classes  of 
distilling  apparatus,  of  which  the  minor  varieties  are  too  numerous  to  be 
specially  enumerated.  These  classes  are:  first,  simple  stills  with  worm 
condenser  heated  by  direct  firing ;  second,  simple  stills  with  closed  ' '  wash- 
warmer";  third,  stills  with  rectifying  "wash-warmer";  fourth,  stills 
with  "  wash- warmer, "  rectifying  and  dephlegmator  apparatus  for  inter- 
mittent working ;  and,  fifth,  similar  forms  of  construction  for  continuous 
working.  The  first  and  simplest  of  these  classes  hardly  needs  any  special 
description.  The  stills  are  usally  of  copper,  flat-bottomed,  and  often  of 
great  size,  especially  in  Irish  and  Scotch  whiskey  distilleries.  It  is  obvi- 
ous that  their  use  involves  a  great  waste  of  fuel.  Therefore  one  of  the 
earliest  devices  for  economizing  the  heat  of  distillation  consisted  in 
interposing  between  the  still  and  the  refrigerating  apparatus  a  "wash- 
warmer,  ' '  or  vessel  filled  with  the  liquid  ready  for  distillation.  Through 
this  vessel  the  pipe  conveying  the  hot  vapors  to  the  refrigerator  coil 
passed,  and  the  vapors  partly  condensing  there  heated  up  the  wash, 
which  then  went  into  the  still  quite  hot.  Dorn's  apparatus,  still  some- 
what used  in  smaller  establishments  in  Germany,  accomplished  the  same 
thing,  and  effected  a  partial  rectification  of  the  distillate  by  having  inter- 
posed between  the  still  and  the  refrigerator  a  vessel  divided  horizontally 
into  two  compartments  by  a  diaphragm  of  copper.  The  upper  and 
larger  compartment  served  as  a  wash-warmer,  and  through  it  the  tube 
conveying  the  vapors  from  the  still  passed  into  the  lower  compartment, 
where  at  first  the  distillate  condensed.  As  the  wash  becomes  warmed  up 
this  distillate  gives  off  alcoholic  vapors,  which  then  pass  on  and  are  con- 
densed in  the  worm,  while  the  watery  portion  is  allowed  to  flow  back  into 
the  still  by  a  side-connection.  It  is  obvious  that  this  rectifying 
action  can  be  increased  by  the  introduction  of  two  or  more  such  vessels 
between  the  still  and  the  final  condenser,  and  so  a  distillate  much  richer 
in  alcohol  be  obtained. 

Another  principle  was  now  brought  into  play  "in  effecting  a  fractional 
condensation,  that  of  dephlegmation,  or  chilling  the  vapor  coming  off  by 
contact  with  metallic  diaphragms  so  that  a  portion  of  it,  and  of  course 
the  most  watery,  is  condensed  and  separated  while  the  richly  alcoholic 


MANUFACTURE  OF  DISTILLED  LIQUORS. 


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246  FERMENTATION  INDUSTRIES. 

vapor  passes  on  into  the  rectifier  or  condenser.  Three  types  of  these 
most  elaborate  apparatus  may  be  briefly  referred  to :  the  Pistorius  appa- 
ratus, used  in  Germany  for  the  thick  potato-mashes  of  that  country, 
which  is  intermittent,  the  Coffey  still,  used  in  England  and  Scotland  for 
the  thinner  worts  from  grain,  and  the  column  apparatus,  first  introduced 
by  Savalle  and  improved  by  later  inventors,  which  is  used  ?n  Prance  for 
distilling  wines  and  in  Germany  to  follow  up  the  work  of  the  Pistorius 
or  similar  apparatus.  Both  the  Coffey  still  and  the  column  apparatus  are 
continuous  in  action.  In  the  Pistorius  apparatus,  two  boilers  and  a 
wash-warmer  are  used  for  the  fresh  mash,  and  are  connected  so  that 
the  vapors  from  the  first  boiler  pass  into  the  second  boiler,  heating  it  up 
and  in  time  driving  vapor  from  it,  which  then  passes  around  the  wash- 
warmer  and  goes  through  several  dephlegmators  placed  one  above  the 
other.  In  these  the  watery  alcohol  is  continually  being  condensed  and 
running  back  to  the  second  boiler,  while  the  uncondensed  vapor  which 
escapes  from  the  top  dephlegmator  goes  finally  to  the  refrigerating 
apparatus.  The  Pistorius  apparatus  has  been  improved  upon  by  Gall, 
Schwartz,  and  Siemens.  The  Coffey  still,  illustrated  in  Fig.  62,  consists 
of  two  columns  placed  side  by  side,  made  of  wood  and  lined  with  copper. 
The  analyzer,  A,  is  divided  into  twelve  small  compartments  by  four 
horizontal  plates  of  copper,  a,  perforated  with  numerous  holes  and  fur- 
nished with  valves  opening  upwards.  Dropping-pipes,  &  &,  are  also 
attached  to  each  plate,  the  upper  end  of  the  pipe  being  an  inch  or  two 
above  the  plate  and  the  lower  end  dipping  into  a  shallow  pan,  c,  placed 
on  the  lower  plate.  The  second  column  or  rectifier,  B,  receives  the  spirit- 
uous vapors  passing  from  the  column  A  through  the  pipe  g.  This  column 
is  also  divided  into  compartments  like  A,  but  there  are  fifteen  instead 
of  twelve.  The  ten  lower  diaphragms,  I,  are  pierced  with  small  holes  and 
furnished  with  drop-pipes,  while  the  upper  five  have  only  one  large 
opening  surrounded  by  a  ring  to  prevent  the  finished  spirit  from  return- 
ing. Between  each  of  these  compartments  passes  a  bend  of  a  long  zigzag 
pipe,  n  n',  one  end  of  which  is  attached  to  the  pump  m,  whilst  the  other 
end  discharges  the  contents  of  the  pipe  into  the  top  of  the  column  A, 
as  indicated  by  the  arrow.  The  following  is  the  working  of  the  appa- 
ratus. In  the  first  place,  the  fermented  liquor  or  wash  is  pumped  up  by 
the  pump  m  until  the  zigzag  pipe  is  filled  and  the  wort  flows  over  the 
compartments  a  a  a.  Steam  is  then  admitted  into  the  compartments  of 
the  analyzer  by  the  pipe  d  and  heats  the  wash,  which  is  deprived  of  all 
its  alcohol  by  the  time  it  reaches  the  bottom  of  the  clyinder  and  flows  off 
by  e  f  as  spent  wash.  The  strong  spirituous  vapor  passes  through  g  to 
the  rectifier,  and  at  last  through  the  worm  c  of  the  refrigerator  into  the 
receiver.  The  Coffey  still  is  recognized  as  the  best  and  most  economical 
device  for  preparing  a  highly-concentrated  spirit  in  a  single  operation. 
It  is  specially  adapted  for  preparing  from  grain-mashes  what  is  called 
"silent  spirit,"  which  is  almost  entirely  destitute  of  flavor,  and  of  a 
strength  ranging  from  fifty-five  to  seventy  over  proof.  It  is  not  so  well 
adapted  for  the  distillation  of  malt  whiskey  as  fire-heated  stills,  because 
the  peculiar  flavor  of  the  whiskey  depends  upon  the  retention  by  the 


MANUFACTURE  OF  DISTILLED  LIQUORS. 


247 


alcoholic  distillate  of  the  volatile  oils  produced  in  the  mash,  and  the 
Coffey  still  separates  the  alcohol  from  these  as  well  as  other  impurities. 
The  forms  of  apparatus  used  in  France  for  the  distillation  of  wines  are 
illustrated  in  that  of  Cellier-Blumenthal  as  improved  by  Derosne,  shown 


FIG.  63. 


in  Fig.  63.  The  alcoholic  vapors  from  A  pass  into  B,  and  thence  into  the 
rectifying  column  C,  which  contains  a  series  of  perforated  metal  cups 
over  which  wine  from  the  wine-warmer,  E,  is  trickling.  The  vapors  thus 
enriched  go  through  the  upper  rectifying  column,  D,  and  thence  to  the 
wine-warmer,  E,  M'hich  serves  as  a  first  condenser,  and  then  to  the  cold 


248 


FERMENTATION  INDUSTRIES. 


FIG.  64. 


FIG.  65. 


FIG.  66. 


MANUFACTURE  OF  DISTILLED  LIQUORS.  249 

condenser,  F,  and  so  to  the  collecting  vessel.  After  the  operation  is  well 
under  way  the  supply  of  wine  can  be  introduced  from  H  through  G,  k, 
and  E,  while  the  de-alcoholized  liquid  can  be  run  off  from  the  lower  side 
of  A. 

Another  form  of  still  very  largely  used  in  France  and  Belgium,  espe- 
cially for  thin  mashes  like  molasses  and  beet-mash,  is  that  of  Savalle, 
illustrated  in  Fig.  64.  It  is  a  continuous-working  apparatus.  B  is  the 
still  proper  heated  by  steam-pipes,  A  is  the  rectifying  column,  C  is  for 
catching  froth,  D  is  a  warm  tube  condenser  and  E  the  cold  condenser. 
The  elements  which  form  the  condensing  and  rectifying  parts  of  the 
column  A  are  shown  in  Figs.  65  and  66.  The  vapors  rising  pass  through 
the  holes  of  the  perforated  plates,  on  which  rests  a  layer  of  condensed 
liquid  which  can  only  drain  down  through  d  into  th'e  cup  c  placed  below 
it.  From  these  cups  it  overflows  upon  the  perforated  plate  and  is  again 
drained  off  by  the  next  connecting  tube,  d.  The  rising  vapors  are  there- 
fore washed  by  the  liquid  upon  each  perforated  plate. 

4.  RECTIFYING  AND  PURIFYING  OF  THE  DISTILLED  SPIRIT. — The 
products  from  the  preliminary  distillation  from  the  fermented  grain-  or 
potato-mash  are  not  at  first  sufficiently  strong,  but  must  be  strengthened 
by  rectifying.  In  England,  the  spirits  obtained  by  the  first  distillation 
from  grain-mash  are  generally  called  low  wines,  and  have  a  specific 
gravity  of  about  .975.  By  rectifying,  or  doubling,  a  crude  milky  spirit, 
abounding  in  oil,  at  first  comes  over,  followed  by  clear  spirit,  which  is 
then  caught  separately.  "When  the  alcoholic  strength  of  the  distilled 
liquid  has  considerably  diminished,  the  remaining  weak  spirit  that  distils 
over,  called  faints,  is  caught  separately  and  mixed  with  the  low  wines 
preparatory  to  another  distillation.  The  rectifying  is  most  rapidly  and 
effectually  done  in  the  several  forms  of  column  apparatus,  the  best  of 
which  will  yield  a  very  pure  alcohol  in  one  or  two  operations. 

An  improved  Savalle  rectifying  colunm  as  used  generally  in  French 
and  Belgian  distilleries  is  shown  in  Fig.  67.  It  consists  of  a  still,  A. 
heated  by  closed  steam-coils,  a  rectifying  column,  B,  two  tubular  con- 
densers, C  and  D,  from  the  upper  of  which  any  condensed  vapors  flow 
back  into  the  rectifying  column  as  "low  wines,"  while  the  lower  con- 
denser takes  the  more  volatile  product  and  passes  it  on  as  high-grade 
alcohol  to  the  receiving-vessel,  F. 

The  purifying  of  raw  spirit,  notably  that  from  grain  and  potatoes, 
from  what  is  called  fusel  oil  (propyl,  isobutyl,  and  amyl  alcohols)  is  also 
a  matter  of  great  importance  if  the  spirit  is  to  be  used  as  the  basis  of  any 
manufactured  liquors.  This  fusel  oil  sticks  persistently  to  the  alcoholic 
distillates,  and  alcohol  rectified  until  it  reaches  a  strength  of  ninety-five 
or  ninety-six  per  cent,  by  volume  contains  fusel  oil.  Some  acetaldehyde 
also  remains  dissolved  in  the  alcohol,  giving  the  raw  spirit  a  bitter  taste. 
The  rectifier's  method  is  to  dilute  the  alcohol  with  water  until  it  is  about 
fifty  per  cent,  strength,  by  which  means  the  fusel  oil  separates  out  in- 
soluble in  the  dilute  spirit,  and  then  to  filter  through  wood  charcoal. 
Another  method  which  has  been  experimented  upon  on  a  large  scale, 
known  as  the  Bang  and  Ruffin  process,  is  to  shake  up  the  diluted  spirit 


250 


FERMENTATION  INDUSTRIES. 


with  petroleum  oils,  which  have  the  power  of  absorbing  the  fusel  oil  and 
so  withdrawing  it  from  the  dilute  alcohol. 

In  this  country  the  storage  of  the  grain  spirit  in  charred  oaken 
barrels  in  warm  rooms  is  extensively  practised  as  a  method  of  improving 

FIG.  67. 


the  quality  of  the  spirit.  It  was  supposed  that  the  fusel  oil  disappeared 
during  this  storage,  but  Crampton  *  has  shown  that  it  does  not  and  is 
merely  masked  by  the  empyreumatic  extractive  matter  taken  up  from  the 
wood.  Esters,  however,  are  formed  and  the  rawness  disappears. 

5.  MANUFACTURE  OF  ALCOHOLIC  BEVERAGES  FROM  RECTIFIED  SPIRIT. — . 
Much  of  the  rectified  spirit,  from  whatever  source  derived,  is  used  in 

*  Journ.  Amer.  Chem.  Soc.,  Jan.,  1908,  p.  98. 


MANUFACTURE  OF  DISTILLED  LIQUORS.  251 

connection  with  the  manufacture  of  wines  for  fortifying  them  and  in 
arresting  fermentation  at  any  desired  stage.  The  so-called  "silent 
spirit  "  made  in  England  by  the  use  of  the  Coffey  still  from  grain- wort 
is  largely  utilized  in  the  manufacture  of  factitious  brandies  and  wines, 
and  the  same  thing  applies  to  the  spirit  manufactured  in  France  from 
beet-roots  and  beet-root  molasses,  where  it  is  made  to  supply  the  deficien- 
cies in  the  wine  and  Cognac  production.  The  composition  of  many  of 
these  factitious  or  imitation  liquors  will  be  spoken  of  in  the  next  section 
in  enumerating  the  products  of  this  industry. 

m.  Products. 

1.  RECTIFIED  AND  PROOF  SPIRIT. — "Rectified  spirit  "  is  the  name  often 
given  to  the  most  concentrated  alcohol  producible  by  ordinary  distilla- 
tion.   The  British  Pharmacopoeia  describes  rectified  spirit  as  containing 
ninety  per  cent,  by  volume  real  alcohol  and  having  a  specific  gravity  of 
.834.     The  United   States  Pharmacopoeia  under  the  name  "alcohol  " 
simply  calls  for  a  spirit  containing  94.9  per  cent,  by  volume  of  real 
alcohol  and  having  a  specific  gravity  of  .816  at  60°  F.    The  "spirit  "  of 
the  German  Pharmacopoeia  has  a  specific  gravity  of  .830  to  .834,  and 
hence  corresponds  more  nearly  to  the  British  ' '  rectified  spirit. ' ' 

' '  Proof  spirit  "  is  a  term  in  constant  use  in  England  for  the  purposes 
of  excise,  and  its  strength  was  defined  by  act  of  Parliament  to  be  such 
that  at  51°  F.  (10°  C.)  thirteen  volumes  shall  weigh  the  same  as  twelve 
volumes  of  distilled  water.  The  "proof  spirit  "  so  made  will  have  a 
specific  gravity  of  .91984  at  15.5°  C.  (60°  F.)  and  contain,  according  to 
Fownes,  49.24  per  cent,  by  weight  of  alcohol  and  50.76  per  cent,  of 
water.  Spirits  weaker  than  proof  are  described  as  U.  P.  (under  proof), 
stronger  than  proof  as  0.  P.  (over  proof)  ;  thus,  a  spirit  of  fifty  U.  P. 
means  fifty  water  and  fifty  proof  spirit,  while  fifty  0.  P.  means  that 
the  alcohol  is  of  such  strength  that  to  every  one  hundred  of  the  spirit 
fifty  of  water  would  have  to  be  added  to  reduce  it  to  proof  strength. 
Tables  are  in  use  which  give  for  alcohol  of  a  given  specific  gravity  at 
15.5°  C.  (60°  F.)  the  corresponding  percentage  by  weight,  percentage 
by  volume,  and  percentage  of  proof  spirit  contained.  (See  Wynter 
Blyth,  Foods,  Composition  and  Analysis,  5th  ed.,  p.  380.) 

2.  ALCOHOLIC  BEVERAGES  MADE  BY  DIRECT  DISTILLATION  OF  THE  FER- 
MENTATION PRODUCTS. — Arrack. — Any  alcoholic  liquor  is  called  ' '  arrack  ' ' 
in  the  East,  but  arrack  proper  is  a  liquor  distilled  either  from  toddy,  the 
fermented  juice  of  the  cocoa-nut  palm,  or  from  malted  rice.    The  arrack 
from  Goa  and  Columbo  is  considered  the  best,  and  is  made  from  toddy 
alone.    This  latter  is  gotten  by  the  incision  of  the  palm,  arid  is  collected 
in  pots  hung  to  the  tree  under  the  cuts.    It  is  then  fermented  and  dis- 
tilled.    In  preparing  the  other  variety,  as  carried  out  in  Batavia  and 
Jamaica,  the  rice  is  covered  with  water  and  allowed  to  germinate,  dried 
at  a  temperature  of  59°  F.,  which  arrests  germination,  and  then  a  wort 
is  made  from  the  malted  rice  in  the  same  manner  as  from  malted  grain, 
which  is  afterwards  distilled.     The  commonest  pariah  arrack  of  India  is 


252  FERMENTATION  INDUSTRIES. 

generally  narcotic,  very  intoxicating,  and  unwholesome.  It  is  prepared 
from  coarse  jaggery  sugar,  spoilt  toddy,  refuse  rice,  etc.,  and  rendered 
more  intoxicating  by  the  addition  of  hemp  leaves,  poppy-heads,  juice  of 
stramonium,  and  similar  deleterious  substances. 

Brandy  in  its  purest  form  (Cognac)  is  the  direct  product  of  the  dis- 
tillation of  French  wines.  Its  peculiar  flavor  and  aroma  are  due  to  the 
presence  of  ethyl  pelargonate  (osnanthic  ether).  The  better  qualities 
of  Cognac  are  distilled  from  white  wines,  the  inferior  varieties  from  the 
dark-red  Spanish  and  Portuguese  wines  or  from  the  marc  or  refuse  of 
the  wine-press,  and  called  eau  de  vie  de  marc.  A  great  deal  is  also  entirely 
factitious,  being  mixtures  of  grain  spirit  and  water  to  which  different 
coloring  and  aromatic  substances  have  been  added.  When  first  dis- 
tilled, brandy,  like  other  spirituous  liquors,  is  colorless,  when  it  is  known 
as  white  brandy,  and  continues  so  if  kept  in  glass-  or  stone-ware,  but  if 
stored  in  oak  casks,  as  is  usually  the  case,  it  gradually  acquires  a  yel- 
lowish tint  from  the  wood,  and  it  is  then  termed  pale  brandy.  The  still 
deeper  color  which  it  frequently  possesses  is  given  it  by  the  addition  of 
caramel-color,  which  was  originally  designed  to  simulate  the  appearance 
of  an  old  brandy  long  stored  in  casks.  The  coloring  matter  is  also  some- 
times prepared  from  catechu  and  similar  astringent  and  aromatic  sub- 
stances. 

Numerous  recipes  for  factitious  brandies  are  furnished  for  the  use 
of  rectifiers  in  making  up  imitations  of  Cognac.  Two  such  recipes  are 
given : 

No.  1. — Powdered  catechu,  100  grammes ;  sassafras-wood,  10  grammes ; 
balsam  of  tolu,  10  grammes;  vanilla,  5  grammes;  essence  of  bitter 
almonds,  1  gramme;  well-flavored  alcohol  (at  85°),  1  litre. 

No.  2. — Malt  spirit  (17  U.  P.),  100  gallons;  nitrous  ether,  2  quarts; 
ground  cassia-buds,  4  ounces ;  bitter  almond  meal,  5  ounces ;  sliced  orris- 
root,  6  ounces;  cloves  in  powder,  1  ounce;  capsicum,  iy2  ounces;  good 
vinegar,  3  gallons ;  brandy-coloring,  3  pints ;  powdered  catechu,  2  pounds ; 
full-flavored  Jamaica  rum,  2  gallons.  Mix  in  an  empty  Cognac-cask  and 
macerate  for  a  fortnight,  with  occasional  stirring.  Produces  106  gallons 
at  21  or  22  U.  P. 

Kirschwasser  is  a  spirituous  liquor  obtained  in  the  Black  Forest  and 
in  Switzerland  by  the  distillation  of  cherries.  These  are  picked  free  from 
the  stalks  and  only  the  sound  fruit  taken.  They  are  crushed  for  the 
extraction  of  the  juice,  and  a  portion  of  the  cherry-stones  are  then  sepa- 
rately crushed  so  as  to  bruise  the  kernels  and  returned  to  the  juice. 
These  bruised  kernels  impart  the  almond  flavor  to  the  product  and  give 
to  it  a  small  quantity  of  prussic  acid  (.15  gramme  per  litre  in  good 
kirsch  and  more  in  inferior  kinds).  After  fermentation  the  liquor  is 
drawn  off  and  distilled  by  steam.  The  kirsch  is  colorless,  of  agreeable 
odor  and  flavor,  which  improves  by  keeping,  and^equal  in  strength  to  the 
strongest  spirit. 

Rum  is  a  spirit  obtained  in  the  West  Indies,  notably  in  Jamaica,  Mar- 
tinique, and  Guadeloupe,  from  the  molasses  of  the  sugar-cane  by  fer- 
mentation and  distillation.  The  process  of  fermentation  of  the  molasses 


MANUFACTURE  OF  DISTILLED  LIQUORS.  253 

as  carried  out  in  Jamaica  has  already  been  described.  When  new,  rum 
is  white  and  transparent,  and  has  when  freshly  distilled  an  unpleasant 
odor,  due  to  oils  contained.  These  are  got  rid  of  by  treatment  with 
charcoal  and  lime.  It  owes  its  characteristic  flavor  to  butyric  ether, 
which  compound  is  also  prepared  artificially  on  a  large  scale,  and  as  rum 
essence  is  used  with  "silent  spirit  "  to  make  a  factitious  rum.  Rum  is 
always  colored  artificially  with  caramel-color. 

Whiskey  is  the  spirit  obtained  from  the  fermented  wort  of  corn,  rye, 
and  barley,  either  raw  or  malted.  In  Scotland  and  Ireland,  malted 
barley,  pure  or  mixed  with  other  grain,  is  chiefly  used ;  in  the  prepara- 
tion of  the  Bourbon  whiskey  of  Kentucky  partially-malted  corn  and  rye 
are  taken,  while  for  the  Monongahela  whiskey  of  Western  Pennsylvania 
only  rye  (with  ten  per  cent,  of  malt)  is  used. 

The  difference  between  the  Irish  and  the  Scotch  whiskeys  lies  mainly 
in  the  fact  that  the  latter  is  distilled  from  barley  malt  dried  by  peat 
fuel,  giving  a  characteristic  smoky  flavor  to  the  spirit,  while  the  malt 
of  the  Irish  whiskey  is  destitute  of  this  flavor.  Both  are  in  general 
pot-still  whiskies,  while  the  product  of  the  Coffey  still  with  less  flavor 
is  used  for  blending.  The  Irish  "poteen  "  whiskey,  however,  has  the 
smoky  flavor  and  this  is  imitated  by  the  addition  of  one  or  two  drops 
of  creosote  to  the  gallon  of  spirits. 

3.  ALCOHOLIC  BEVERAGES  MADE  FROM  GRAIN  SPIRIT  BY  DISTILLATION 
UNDER  SPECIAL  CONDITIONS. — Gin  is  common  grain  spirit  distilled  and 
aromatized  with  juniper-berries,  either  when  the  "low  wines  "  are  con- 
centrated or  later,  using  full-strength  spirit.     The  proportion  employed 
is  variable,  depending  upon  the  nature  of  the  spirit ;  usually  one  kilo- 
gramme of  berries  is  enough  to  flavor  one  hectolitre  of  raw  grain  spirit. 
The  finest  gin,  known  as  ' '  Hollands, ' '  is  made  in  the  distilleries  of  Schie- 
dam, whence  also  the  name  "Schiedam  Schnapps."    Strassburg  turpen- 
tine, oil  of  fennel,  coriander  and  cardamom  seeds  are  frequently  sub- 
stituted either  wholly  or  in  part  for  the  juniper-berries,  particularly  in 
the  English-made  gin.    The  quality  and  healthfulness  of  the  gin  depend 
largely  upon  the  purity  of  the  spirit  used  in  the  distillation,  whether 
raw  or  rectified. 

It  is  obvious  that  many  factitious  brandies  belong  also  in  this  class, 
being  made  by  distillation  of  mixtures  of  which  grain  spirit  is  the  basis 
and  not  by  distillation  of  wine.  These  have  already  been  described. 

4.  LIQUEURS  AND  CORDIALS. — Liqueurs  is  the  name  now  given  to  such 
spirituous  drinks  as  are  obtained  by  mixing  various  aromatic  substances, 
such  as  anise,  absinthe,  essence  of  orange-peel,  etc.,  with  brandy  or  alco- 
hol.    Most  are  obtained  by  steeping  in  pure  brandy  or  spirit  different 
fruits  or  aromatic  herbs  and  submitting  the  resulting  liquid  to  distilla- 
tion.   They  are  then  colored,  and  are  usually  sweetened  with  sugar.    The 
best  known  of  them,  absinthe,  contains  a  characteristic  ingredient,  oil  of 
wormwood,  to  which  its  deleterious  effects  on  the  nervous  system  are 
supposed  to  be  due.    At  the  same  time  the  amount  of  total  essential  oils 
held  dissolved  in  the  strongly  alcoholic  liquid  is  such  that  when  diluted 
with  water  the  solution  becomes  milky  and  turbid. 


254 


FERMENTATION  INDUSTRIES. 


Among  the  liqueurs  may  be  enumerated  Absinthe  (consumed  chiefly 
in  Paris),  Anisette  (made  in  the  south  of  France),  Chartreuse  (made  by 
the  monks  of  the  Grande  Chartreuse  Monastery  near  Grenoble),  Curaqoa 
(originally  made  in  Plolland  of  Curacoa  oranges),  Maraschino  (made  in 
Italy  of  Dalmatian  cherries),  Ratafia  (made  in  France  from  a  great 
variety  of  fruits),  and  Usquebaugh  (a  strong  cordial  made  in  Ireland. 
It  furnishes  the  name  from  which  the  word  whiskey  is  derived). 

The  composition  of  the  several  alcoholic  liquors  enumerated  cannot 
be  given  in  great  detail,  as  their  differences  depend  so  largely  upon  the 
flavoring  and  aromatic  ethers  and  essential  oils,  which  are  present  in 
very  minute  quantities.  Their  general  differences  in  alcoholic  strength 
and  the  extract  and  ash  of  several  are,  however,  given  on  the  authority 
of  Konig :  * 


Alcohol 

Alcohol 

Alcohol 

Alcohol 

by 

by 

by 

by 

volume. 

weight. 

volume. 

weight. 

Russian  Dobry  wutky 

620 

54.2 

Gin  ...       

47.8 

40.3 

Scotch  whiskey  .     .    . 

50.3 

42.8 

Ordinary  German  schnapps 

45.0 

37.9 

49  9 

42  3 

Rum   .        

49.7 

42.2 

English  whiskey     .    . 

49.4 

41.9 

French  Cognac  brandy  .    . 

55.0 

47.3 

American  whiskey  .    . 

60.0 

52.2 

And  in  one  hundred  cubic  centimetres  of  the  following: 


Specific 
gravity. 

Alcohol  by 
volume. 

Alcohol  by 
weight. 

Extract. 

Ash. 

0.9158 

60.5 

52.7 

0.082 

0.024 

Cognac    

0.8987 

69.5 

61.7 

0.645 

0.009 

Rum     

0.9378 

51.4 

34.7 

1.260 

0.059 

The  composition  of  some  of  the  well-known  liqueurs  is  also  given  on 
the  same  authority :  f 


Specific 
gravity. 

Alcohol 
by 
volume. 

Alcohol 
by 

weight. 

Extract. 

Cane- 
sugar. 

Other  ex- 
tractions. 

Ash. 

Absinthe  

0.9116 

58  93 

0  181 

032 

Bonekamp  of  Maag  bitters 
Benedictine  bitters  .  .  . 
Ginger  

0.9426 
1.0709 
1.0481 

50.0 

52.0 
47  5 

42.5 
44.4 
40  2 

2.05 
36.00 
27  79 

32.57 
2592 

3.43 

1  87 

0.106 
0.043 
0.141 

Creme  de  menthe  .... 
Anisette  of  Bordeaux  .  . 
Curaqoa  

1.0447 
1.0847 
1.0300 

48.0 
42.0 
550 

40.7 
35.2 
47  3 

28.28 
34.82 
28  60 

27.63 
3444 
28  50 

0.65 
0.38 
0  10 

0.068 
0.040 
0040 

Kummel  liqueur  .... 
Peppermint  liqueur  .  .  . 
Swedish  punch  

1.0830 
1.1429 
1.1030 

33.9 
34.5 
26.3 

28.0 
28.6 
21  6 

32.02 
48.25 
36  61 

31.18 
47.35 

0.84 
0.90 

0.058 
0.068 

*  Konig,  Nahrungs-  und  Genussmittel,  3te  Auf.,  vol.  i,  p.  992. 
f  Ibid.,  p.  997.  $  Oil  of  wormwood. 


MANUFACTURE  OF  DISTILLED  LIQUORS. 


255 


5.  SIDE-PRODUCTS. — The  distiller's  residue  (Schlempe,  vinasse)  forms 
a  side-product  of  considerable  value  as  a  cattle  food  because  of  its  com- 
position. It  is  especially  rich  in  protein  matter,  fat,  and  non-nitrogen- 
ous extractive,  or  carbohydrates.  The  residues  from  the  beet-  and  cane- 
molasses  distillation,  moreover,  yield  an  ash  very  rich  in  potash  salts,  so 
that  they  constitute,  especially  in  France,  a  very  important  source  of 
potashes.  The  constituents  of  several  of  these  distillery  residues  in  the 
moist  state  are  here  given  on  the  authority  of  Konig :  * 


Nitro- 

Non-nitro- 

Water. 

Fat. 

genous 

genous 

Cellulose. 

Ash. 

matter. 

extract. 

Kye-mash  residues  (ten 

analyses)  .            ... 

93.48 

0.22 

1.40 

4.05 

0.52 

0.33 

Potato-mash        residues 

(six  analyses)  .... 

95.10 

0.17 

1.17 

2.17 

0.92 

0.47 

Molasses  residues    .    .   . 

91.86 

2.04 

4.56 

•    • 

1.54 

Two  complete  analyses  of  distillery  residues  dried  by  centrifugating 
and  heating  in  kilns  are  given  on  the  authority  of  Rosenbaum :  f 

Water     11.62  7.83 

Ash    6.50  16.40 

Crude  proteid  matter   21.44  23.08 

Crude    fibre     10.54  8.60 

Non-nitrogenous  extractives    38.96  40.54 

Crude    fat    11.44  3.55 

100.00  100.00 

Of  these  constituents  the  following  were  assimilable  as  food: 


Albuminoids    17.20 

Carbohydrates    37.40 

Fat  9.10 


18.50 

39.40 

2.85 


IV.  Analytical  Tests  and  Methods. 

The  most  important  determination  in  this  class  of  beverages  is  the 
alcoholic  strength.  In  the  case  of  rectified  or  proof  spirit,  a  simple 
specific  gravity  determination  is  all  that  is  necessary,  and  then  the  per- 
centage strength  can  be  found  from  the  alcohol  tables  that  have  been 
prepared.  The  determination  should  be  made  at  15.5°  C.  (60°  F.),  or 
if  at  another  temperature,  a  correction  in  the  reading  must  be  made. 
By  multiplying  the  number  of  degrees  above  or  below  15°  by  .4  and 
adding  the  product  to  the  percentage  given  by  the  table  when  the  tem- 
perature is  lower  than  15°,  or  deducting  it  when  the  temperature  is 
above,  we  get  a  correct  result.  In  freshly-distilled  and  colorless  whiskeys 
and  brandies,  in  which  the  amount  of  extract  is  trifling,  the  alcoholic 


*  Konig,  Nahrungs-  und  Genussmittel,  2te  Auf.,  vol.  ii,  p.  468. 
tJahresber.  der  Chem.  Technol.,  1887,  p.  1058. 


256  FERMENTATION  INDUSTRIES. 

percentage  can  also  be  determined  with  sufficient  accuracy  by  the  specific 
gravity  method.  In  such  liquors  as  contain  more  extractive  matter,  like 
rum  and  the  liqueurs  and  cordials,  the  alcohol  must  first  be  distilled  off, 
and  then  made  up  to  original  volume  with  distilled  water,  as  described 
on  p.  235. 

The  detection  and  determination  of  fusel  oil,  which  is  a  persistent 
impurity  in  potato  and  grain  spirit,  is  one  of  the  most  important  tests 
to  be  made.  To  detect  it,  the  greater  part  of  the  alcohol  is  distilled  off 
at  as  low  a  temperature  as  possible,  the  residual  liquid  mixed  with  an 
equal  amount  of  ether  and  well  shaken.  The  ethereal  layer  is  then  sepa- 
rated and  allowed  to  evaporate  spontaneously,  when  amyl  alcohol,  if 
present,  will  be  recognized  in  the  residue  by  its  smell  and  chemical 
characters.  Petroleum-ether  may  be  advantageously  substituted  for  the 
ether  in  this  test. 

Two  quantitative  methods  are  now  in  use,  the  Roese  method  in  which 
the  increase  in  volume  of  a  measured  amount  of  chloroform  when  shaken 
with  a  distillate  from  the  sample  in  question  is  compared  with  that 
obtained  in  a  blank  experiment  with  fusel-free  alcohol,  and  the  Allen- 
Marquandt  method  in  which  the  fusel  oil  extracted  with  a  solvent  (pref- 
erably carbon  tetrachloride)  is  oxidized  by  bichromate  of  potash  and 
sulphuric  acid,  the  volatile  acids  produced  distilled  off  and  titrated  with 
one-tenth  normal  sodium  hydroxide  solution.  For  full  working  direc- 
tions for  the  use  of  these  processes  see  "Official  and  Provisional  Methods 
of  Analysis,"  Bulletin  No.  107  (Revised)  Bureau  of  Chemistry,  Depart- 
ment of  Agriculture. 

Caramel  (burnt  sugar)  is  used  for  coloring  and  flavoring  spirits,  and 
may  be  detected  by  the  Crampton  and  Simons  test.  Evaporate  fifty 
cubic  centimetres  of  the  sample  nearly  to  dryness  on  the  water-bath,  wash 
into  a  fifty  cubic  centimetre  flask,  add  twenty-five  cubic  centimetres  of 
absolute  alcohol,  cool  to  a  definite  temperature  and  dilute  to  mark  with 
water.  Transfer  twenty-five  cubic  centimetres  to  an  apparatus  such  as 
is  used  in  the  Roese  fusel  oil  determination,  add  ether  (fifty  cubic  cen- 
timetres) and  shake  at  intervals  for  half  an  hour  and  allow  to  settle. 
After  withdrawing  the  water,  the  aqueous  layer  is  compared  with  twenty- 
five  cubic  centimetres  of  the  solution  which  have  not  been  treated  with 
ether.  The  amount  of  color  removed  is  expressed  on  the  percentage 
basis. 

The  Amthor  test,  as  modified  by  Lasche,  is  based  upon  the  action 
of  paraldehyde  solution  upon  a  sample  of  the  liquor.  A  permanent  tur- 
bidity after  ten  minutes  indicates  caramel. 

Tannin  is  often  present  in  brandy  and  whiskey,  being  chiefly  extracted 
from  the  casks  used  in  storing.  Sometimes,  as  in  factitious  brandies,  it 
is  purposely  added  in  the  form  of  tincture  of  oak-bark.  It  may  be 
detected  by  the  darkening  produced  on  adding  ferric  chloride  to  the 
spirit,  and  any  reaction  thus  obtained  may  be  'confirmed  by  boiling  off 
the  alcohol  from  another  portion  of  the  spirit  and  adding  solution  of 
gelatine  to  the  residual  liquid,  when  a  precipitate  will  be  produced  if 
tannin  be  present. 


BREAD-MAKING.  257 

E.  BREAD-MAKING. 

Bread-making  as  ordinarily  conducted  is  to  be  classed  as  one  of  the 
fermentation  industries,  as  the  swelling  of  the  dough  which  must  precede 
the  baking  is  generally  accomplished  by  the  aid  of  the  alcoholic  fermen- 
tation brought  about  by  the  addition  of  ''leaven  "  or  yeast.  For  every 
kilogramme  of  bread,  on  the  average,  2.5  grammes  of  alcohol  and  2.7 
grammes  of  carbon  dioxide  gas  are  produced.  Both  are  lost  in  the 
baking,  but  the  carbon  dioxide  gas  when  first  generated  is  caught  in  the 
thick  and  viscid  dough  and  causes  it  to  swell  up  and  become  spongy  in 
structure.  This  not  only  gives  to  the  bread  when  baked  a  porous  and 
cellular  structure,  but  allows  the  chemical  changes  to  take  place  through- 
out its  entire  substance,  whereby  it  is  made  more  readily  digestible. 

As  the  only  effective  result  of  the  alcoholic  fermentation  is  per- 
formed by  the  carbon  dioxide,  of  course  the  addition  of  chemical  mix- 
tures liberating  carbon  dioxide  gas  in  the  dough  may  be  made  to  obviate 
the  necessity  of  using  leaven  or  yeast,  and  similarly  aerated  breads  may 
be  made  by  simply  forcing  carbon  dioxide  under  pressure  into  the  dough. 

A  few  varieties  of  bread  are  made  from  dough,  baked  without  any 
aeration  either  natural  or  artificial,  such  as  hard  crackers,  the  unleavened 
bread  of  the  Jews,  the  Scotch  oat-cake,  and  the  corn-cake  of  the  Southern 
States.  These  exceptions  are  of  relatively  minor  importance,  and  by  far 
the  largest  amount  of  bread  is  prepared  by  the  aid  of  a  fermentation 
process. 

I.  Raw  Materials. 

1.  FLOTJK. — This  may  be  from  either  wheat,  rye,  barley,  oats,  maize, 
— Indian  corn, — or  rice,  although  wheat  flour  is  used  in  far  the  largest 
amount. 

The  average  composition  of  the  several  cereals  has  already  been  given. 
(See  page  186.)  Wheat  flour  contains  the  following  substances:  starch, 
dextrine,  cellulose,  sugar,  albumen,  gliadin,  or  gluten,  mucin,  fibrin, 
cerealin,  fat,  mineral  matters,  and  water.  The  first  four  are  carbohy- 
drates, or  non-nitrogenous  substances,  and  they  form  nearly  three-fourths 
of  the  entire  weight  of  the  flour.  The  nitrogenous  matter  consists  of  at 
least  five  principles,  three  of  which,  gluten  (or  gliadin),  mucin  (or 
mucedin),  and  fibrin,  constitute  the  bulk  of  the  material  known  as  crude 
gluten,  which  is  the  substance  left  when  flour  is  kneaded  with  water  and 
afterwards  washed  to  remove  the  starch  and  any  soluble  substance.  The 
remaining  two  nitrogenous  principles,  albumen  and  cerealin,  are  soluble 
in  water,  and  are  carried  away  with  the  starch  in  the  process  of  washing. 
Crude  gluten  possesses  a  peculiar  adhesiveness,  arising  from  the  presence 
of  gliadin,  which  is  a  highly  tenacious  body,  and  which  is  not  present  in 
the  same  form  in  other  cereal  flours.  It  is  this  adhesive  property  which 
gliadin  imparts  to  gluten  that  renders  wheaten  flour  so  well  adapted  for 
bread-making  purposes. 

The  vegetable  albumen  mentioned  above  as  soluble  in  cold  water  is 
accompanied  also  by  small  amounts  of  legumin,  or  vegetable  casein, 

17 


258 


FERMENTATION  INDUSTRIES. 


which  is  also  soluble  in  water.  The  cerealin  is  a  soluble  nitrogenized  fer- 
ment occurring  especially  in  the  husk  or  bran  of  wheat  and  other 
cereals.  It  has  a  powerful  fermentative  action  on  starch,  rapidly  con- 
verting it  into  dextrine  and  other  soluble  bodies.  The  presence  of  cere- 
alin in  bran  renders  "whole  meal  "  unsuitable  for  making  bread  by  fer- 
mentation with  yeast,  though  it  can  be  used  with  baking-powders,  and 
"aerated  bread  "  can  be  made  from  it.  The  cerealin  acts  like  malt 
extract,  causing  a  too  rapid  conversion  of  the  starch  into  dextrine  and 
sugar,  and  hence,  although  the  bran  is  rich  in  nitrogenous  food  con- 
stituents and  salts  like  phosphates,  it  is  ordinarily  separated  from  tho 
flour.  The  difference  in  the  composition  of  the  several  parts  of  the 
wheat-grain  is  seen  in  the  following  table  given  by  Church :  * 


FINE  WHITE  FLOUR. 

COARSE  WHE.VT  BRAN. 

In  100 
parts. 

In  1  pound. 

In  100 
parts. 

In  1  pound. 

Water      

13.0 
10.5 
74.3 
0.8 
0.7 
0.7 

2  ounces    35  grains. 
1               297       " 
11               388      " 
0                 57      " 
0                49      " 
0                49   " 

14.0 
15.0 
44.0 
4.0 
17.0 
6.0 

2  ounces  105  grains. 
2               175       < 
7                 17       < 
0               280       ' 
2               316 
0               422 

Fibrin,  etc  

Starch,  etc  

Fat              

Cellulose     

Mineral  matter  

Of  course,  milling  processes  have  to  be  specially  adapted  to  the  sepa- 
ration of  these  quite  different  parts  of  the  wheat-grain,  the  white  flour 
free  from  bran  being  sought.  By  the  old-fashioned  "low-milling  " 
process,  or  grinding  between  stones  placed  very  close  together  and  bolt- 
ing, it  was  impossible  to  obtain  a  flour  entirely  free  from  contamination. 
The  advance  to  "high-milling  "  with  stones  far  apart,  allowing  the  mid- 
dlings which  were  produced  to  be  purified  before  grinding  to  flour,  was 
a  step  which  made  it  possible  to  make  from  winter  wheat  an  excellent 
and  pure  flour.  When,  however,  spring  wheat  with  its  hard  and  brittle 
outer  coats  became  important  commercially,  it  was  necessary  to  resort 
to  the  roller  methods  of  milling,  which,  in  conjunction  with  peculiar 
purifying  machinery,  would  furnish  a  flour  free  from  all  undesirable 
impurities.  This  latter  process  has  now  almost  universally  replaced  the 
other  in  the  newer  mills. 

While  most  of  the  other  cereals  before  mentioned  may  be  found  occa- 
sionally in  admixture  with  wheat  flour,  very  few  are  used  alone  as  sub- 
stitutes for  it.  Rye  flour  is  probably  the  only  one.  It  makes  a  dark- 
colored,  heavy  and  sourish  bread,  which,  however,  keeps  moist  a  long 
time.  It  is  much  used  in  Germany  and  Northern  Europe  under  the  name 
of  "black  bread."  A  more  palatable  bread  may  be  made  from  a  mixture 
of  two  parts  wheat  flour  and  one  part  rye  flour.  This  latter  flour  con- 
tains a  slightly  larger  amount  of  fat  and  of  mineral  matter  than  wheat 
flour.  It  is  never  so  white  as  wheat  flour  and  the  gluten  has  very  little 
adhesive  character.  Ritthausen  states  that  the  gluten  of  rye  flour  con- 

*  A.  H.  Church,  Foods,  etc.,  South  Kensington  Hand-book,  pp.  63  and  64. 


BREAD-MAIQNG.  259 

sists  chiefly  of  mucin  (mucedin)  and  vegetable  casein,  and  that  gliadin 
is  absent  entirely. 

2.  YEAST,  OR  FERMENT. — The  yeast  is  at  present  almost  always  added, 
either  as  brewer's  yeast  or  compressed  yeast.  In  former  times  (and  to  a 
considerable  extent  still  in  France)  wheat  bread  was  made  by  the  use  of 
leaven,  which  consists  of  a  portion  of  dough  left  over  from  a  previous 
baking,  charged  with  the  ferment  and  in  part  changed  by  its  action.  The 
leaven  is  originally  gotten  by  allowing  flour  and  water  to  start  into 
spontaneous  fermentation,  the  nitrogenous  matters  becoming  soluble  and 
attacking  the  starch  and  sugar.  The  leaven  tends,  however,  to  continue 
its  decomposition  and  to  pass  from  the  alcoholic  into  the  lactic  fermen- 
tation. Hence,  if  the  leaven  is  in  the  proper  stage  of  decomposition,  it 
will  induce  the  alcoholic  fermentation  and  generate  carbon  dioxide  gas, 
raising  the  dough ;  if  it  be,  however,  in  a  more  advanced  state  of  decom- 
position, lactic  fermentation  will  be  induced  and  the  bread  will  not  rise, 
but  become  heavy  and  sour.  In  domestic  practice,  to  avoid  this  latter 
result,  saleratus  (bicarbonate  of  potash  or  soda)  is  added  to  the  dough. 
This  neutralizes  the  lactic  acid  as  fast  as  formed,  and  at  the  same  time 
liberates  carbon  dioxide  gas  to  innate  the  dough.  An  excess  of  this  salt, 
however,  makes  the  bread  alkaline  to  the  taste  and  yellow  in  color. 

The  black  rye  bread  of  Gfermany  is  also  made  with  the  aid  of  a  leaven 
known  as  ''sour  dough."  In  this  both  the  alcoholic  and  the  lactic  fer- 
mentations are  in  progress,  the  latter,  however,  preponderating.  Four 
parts  of  such  sour  dough  are  used  for  one  hundred  parts  of  flour. 

The  brewer's  yeast  for  bread-raising  purposes  must  be  a  fresh  and 
vigorous  yeast-growth,  as  its  value  here  depends  largely  upon  the  energy 
of  the  fermentation  set  up  and  the  amount  of  gas  given  off.  Its  appear- 
ance and  characters  have  been  described  before.  (See  p.  207.)  Unless 
of  the  best  quality,  compressed  yeast  is  to  be  preferred  because  of  its 
reliability.  The  manufacture  of  this  latter  is  carried  out  chiefly  in  con- 
nection with  the  spirit  distilleries.  At  the  time  when  the  fermentation 
is  most  energetic,  the  yeast  is  skimmed  off  the  surface  and  conveyed  by 
wooden  shoots  to  steam  sieves,  by  which  the  husks  are  eliminated,  the 
strained  liquid  passing  on  to  the  settling  cisterns.  When  settled  the 
surface  liquid  is  drained  off  and  sent  for  distilling  purposes,  and  the 
yeasty  sediment  mixed  with  starch  and  put  into  the  filter -presses,  which 
squeeze  out  all  the  liquid,  leaving  a  dough-like  paste,  which,  when  suffi- 
ciently dry,  is  packed  into  bags  and  packets  and  is  ready  for  distribu- 
tion. Yeast  from  its  peculiar  slimy  nature  cannot  be  pressed  well,  hence 
the  addition  of  starch,  which  permits  the  removal  of  more  of  the  liquid 
from  the  yeast.  Absolutely  pure  yeasts  do  not  keep  so  well  as  the  same 
yeasts  with  an  addition  of  from  five  to  ten  per  cent,  of  starch.  In  high- 
class  yeasts  the  quantity  added  is  about  five  or  six  per  cent. ;  it  is  often 
added  in  quantity  beyond  this  as  an  adulterant.  A  good  sample  of  com- 
pressed yeast  has  the  following  characteristics:  It  should  be  only  very 
slightly  moist,  not  sloppy  to  the  touch;  the  color  should  be  a  creamy 
white ;  when  broken  it  should  show  a  fine  fracture ;  when  placed  upon  the 
tongue  it  should  melt  readily  in  the  mouth;  it  should  have  an  odor  of 


260  FERMENTATION  INDUSTRIES. 

apples,  not  like  that  of  cheese;  neither  should  it  have  an  acid  taste  or 
odor.  Any  cheesy  odor  shows  that  the  yeast  is  stale  and  that  incipient 
decomposition  has  set  in. 

3.  BAKING  POWDERS. — To  obviate  the  necessity  of  using  yeast  and 
waiting  until  the  dough  should  rise  sufficiently  under  the  influence  of  fer- 
mentation, it  was  early  sought  to  supply  the  necessary  carbon  dioxide  to 
the  dough  by  chemical  reactions.  The  earliest  proposal  was  that  of 
Liebig  to  use  sodium  bicarbonate  and  hydrochloric  acid,  which  should 
evolve  carbon  dioxide  and  leave  sodium  chloride  (common  salt)  in  the 
dough.  Next  was  proposed  sodium  bicarbonate  and  tartaric  acid,  or  acid 
potassium  tartrate  (cream  of  tartar).  More  generally  satisfactory  than 
either  of  these  was  acid  calcium  phosphate  (either  alone  or  with  acid 
magnesium  phosphate),  which  with,  bicarbonate  of  soda  formed  Hors- 
ford's  baking-powder.  More  objectionable  was  the  introduction  of  alum 
with  the  sodium  bicarbonate.  Most  of  these  baking-powder  mixtures, 
then,  have  starch  or  flour  added  as  "filling,"  and  in  amount  varying 
from  twenty  to  sixty  per  cent.  Sesquicarbonate  of  ammonia  is  also  used 
in  many  of  the  mixtures,  replacing  part  of  the  bicarbonate  of  soda. 
Self-raising  flours  have  these  baking-powders  already  added  to  the  flour 
in  such  proportions  as  will  insure  a  spongy  dough  upon  the  simple  addi- 
tion of  water  and  kneading  into  loaves. 

n.  Processes  of  Manufacture. 

1.  THE  MIXING  OF  THE  DOUGH  AND  ITS  FERMENTATION. — The  mixing 
of  the  flour  with  water  is  not  only  for  the  purpose  of  bringing  into  solu- 
tion the  dextrine,  the  sugar,  and  the  soluble  albuminoids,  and  of  allowing 
these  latter  as  peptones  to  act  upon  the  insoluble  consituents  of  the  flour, 
such  as  the  gluten,  but  also  to  penetrate  and  soften  the  starchy  material. 

The  yeast  may  be  added  directly  along  with  the  water  to  some  of  the 
flour  to  prepare  a  "sponge,"  from  which  the  whole  batch  of  dough  is 
afterwards  made,  or  a  "ferment  "  may -be  made  from  the  yeast  with 
potatoes,  which  then  is  used  to  prepare  the  "sponge."  In  the  latter 
case,  potatoes  are  boiled  and  mashed  with  water  into  a  moderately  thin 
liquor,  to  which  the  yeast  is  added,  and  the  fermentation  is  allowed  to 
proceed  for  some  time.  In  either  case,  whether  the  yeast  is  used  direct 
or  a  potato  ferment  is  first  made,  it  is  worked  up  with  a  portion  of  the 
flour  into  a  slack  dough,  which  constitutes  the  sponge,  and  is  set  to  rise 
in  a  warm  place.  When  the  sponge  has  risen  sufficiently  the  remainder 
of  the  flour  is  worked  in  with  sufficient  water  to  which  some  salt  has 
been  added,  and  the  dough  is  made,  kneaded,  allowed  to  stand  again  to 
rise,  and  then  prepared  for  baking. 

The  use  of  potato  ferment  is  based  upon  the  belief  that  the  yeast-cells 
are  strengthened  by  the  soluble  nitrogenous  matter  of  the  potato,  which 
acts  as  a  yeast  stimulant  and  enables  a  smaller  quantity  of  yeast  to 
hydrolyze  a  larger  amount  of  starch.  The  yeast-cells  then  act  very 
rapidly  upon  the  glucose  so  produced  and  develop  the  alcoholic  fermen- 
tation. The  albuminoids  of  the  flour  are  also  softened  and  partially  pep- 
tonized,  and  these  changed  albuminoids  in  turn  assist  in  the  hydrolysis 
of  the  starch. 


BREAD-MAKING.  261 

2.  BAKING. — For  baking,  the  oven  should  have  a  temperature  of  400° 
to  450°  F.  (2006  to  230°  C.).    Before  putting  the  loaves  in,  they  are 
often  wetted  on  the  surface  so  as  to  assist  in  the  prompt  formation  of  a 
crust  that  shall  prevent  the  dough  from  expanding  too  rapidly.     The 
heat  expands  the  gases  throughout  the  loaf  and  so  swells  it  and  vaporizes; 
a  portion  of  the  moisture.    The  action  of  the  heat  and  steam  soon  con- 
verts the  starch  on  the  surface  of  the  loaf  into  dextrine  and  maltose, 
and  these  at  the  high  temperature  are  slighly  caramelized,  thus  giving; 
the  crust  its  brownish  color.    At  the  temperature  of  the  interior  of  the 
loaf   (212°  F.  or  slightly  above)   the  starch-cells  will  have  burst,  the 
coagulable  albuminoids  will  have  been  coagulated,  and  their  diastatic 
power  entirely  destroyed. 

Steam  is  often  injected  into  the  oven  during  the  baking.  The  effect 
is  to  produce  a  glazed  surface  on  the  outside  of  the  crust.  It  not  only 
dextrinizes  and  glazes  the  crust,  but  keeps  the  interior  of  the  loaf  moist 
by  preventing  too  rapid  evaporation.  Of  course,  in  perfectly  tight  ovens 
the  steam  resulting  from  the  evaporation  of  the  moisture  of  the  bread 
is  kept  in,  and  soon  acts  in  the  same  manner  though  in  a  lesser  degree. 

One  hundred  kilogrammes  of  flour  will  yield,  according  to  its  quality, 
from  one  hundred  and  twenty-five  to  one  hundred  and  thirty-five  kilos, 
of  bread. 

3.  USE  OF  CHEMICALS  FOREIGN  TO  THE  BREAD. — Both  alum  and  sul- 
phate of  copper   (and  notably  the  former)   have  been  used  in  baking 
bread  from  inferior  or  unsound  flours  in  order  to  improve  the  appear- 
ance of  the  bread.     This  form  of  adulteration  is  rarely  practised  at 
present.    Much  more  important  in  recent  years  is  the  practice  of  bleach- 
ing flour  with  nitrogen  peroxide.     If  not  used  in  excess  this  promptly 
whitens  the  gray  or  slightly  yellowish  flour  and  increases  the  whiteness 
of  the  bread  baked  from  the  same.    In  the  Alsop  process  most  generally 
employed  the  nitrogen  peroxide  is  formed  by  a  flaming  electric  discharge 
which  causes  nitrogen  and  oxygen  of  the  air  to  combine.    Other  processes 
use  chlorine  or  bromine  or  nitrosyl  chloride. 

Liebig  suggested  the  use  of  lime-water  as  a  means  of  retarding  too 
rapid  decomposition  of  the  starch  during  the  fermentation  of  bread- 
making.  The  bread  made  with  the  proper  amount  of  lime-water  is  said 
by  Jago  *  to  be  more  spongy  in  texture,  pleasant  in  taste,  and  quite  free 
from  sourness.  In  the  bread  the  lime  exists  as  calcium  carbonate,  but 
in  such  quantities  as  to  be  perfectly  harmless. 

in.  Products. 

1.  BREAD. — The  nature  of  the  change  which  the  flour  undergoes  in 
the  bread-baking  process  has  already  been  indicated  in  part.  The  com- 
position of  the  finished  bread  can  now  be  noted.  A  loaf  of  wheaten  bread 
consists  of  two  parts,  the  crumb  and  the  crust,  which  differ  somewhat  in 
both  physical  and  chemical  character.  The  crumb  is  white  in  color, 
more  or  less  vesicular  in  structure,  soft  when  fresh,  and  of  agreeable 
taste  and  sweet  odor ;  the  crust  is  harder,  more  easily  broken,  of  a  chest- 

*  Chemistry  of  Wheat,  Flour,  and  Bread,  etc.,   1886,  p.  326. 


262 


FERMENTATION  INDUSTRIES. 


nut-brown  color,  and  nearly  destitute  of  all  porous  character,  is  sweeter 
in  taste,  because  of  the  greater  change  of  the  starch  into  dextrine  and 
maltose.  The  chemical  differences  between  well-known  forms  of  bread 
are  shown  in  the  following  analyses  from  the  U.  S.  Bureau  of  Chemistry, 
Bulletin  13,  Part  9 : 


Number  of 
analyses. 

Moisture. 

Proteids, 
N  x  6.25. 

Proteids, 
N  x  5.70. 

Ether 
extract. 

Vienna  bread   

10 

38.71 

887 

8.09 

1.06 

Home-made  bread  

2 

33.02 

794 

7.24 

1.95 

Graham  bread  

9 

34.80 

8.93 

8.15 

2.03 

Rye  bread     

7 

33.42 

8.63 

7.88 

0.66 

Miscellaneous  bread  

9 

3441 

760 

693 

1.48 

48 

'     7.13 

10.34 

9.43 

8.67 

Rolls   

11 

2798 

8.20 

7.48 

3.41 

Crude 
fibre. 

Salt. 

Ash. 

Carbohy- 
drates, 
excluding 
fibre. 

Calculated 
calories 
of  com- 
bustion. 

Vienna  bread    

062 

0.57 

1.19 

5372 

4435 

0.24 

0.56 

1.05 

56.75 

4467 

Graham  bread  

1.13 

0.69 

1.59 

53.40 

4473 

Rye  bread     

0.62 

1.00 

1.84 

56.21 

4338 

Miscellaneous  bread  

0.30 

0.49 

1.00 

56.18 

4429 

Biscuits  or  crackers    

047 

099 

1  57 

73.17 

4755 

Rolls    

060 

069 

131 

5982 

4538 

The  differences  between  wheat  bread  made  by  the  usual  fermentation 
process  and  wheat  bread  aerated  by  carbon  dioxide  under  pressure 
(Dauglish  system)  are  shown  also  in  the  following  analyses  by  Dr.  Bell:* 


CONSTITUENTS  OP  THE  BREAD 
KEDUCED  TO  DBY  STATE. 

AERATED  BREAD. 

HOME-MADE  BREAD. 

Tin  loaf. 

Cob  loaf  (Paris 
bread). 

Tin  loaf. 

Cob  loaf  (Paris 
bread). 

Crumb. 

Crust. 

Crumb. 

Crust. 

Crumb. 

Crust. 

Crumb. 

Crust. 

Starch,  dextrine,  cellulose,  etc. 

78.93 
640 

10.30 

1.96 
0.18 
2.23 

78.96 
5.61 

11.28 

1.75 
0.16 
2.24 

82.75 
4.66 

8.58 

1.80 
0  13 
2.08 

82.82 
3.94 

9.09 

1.85 
0.17 
2.13 

78.12 
6.87 

11.65 

1.74 
0.22 
1.40 

77.62 
6.68 

11.17 

2.00 
1.22 
1.31 

82.05 
4.85 

10.59 

1.28 
0.15 
1.08 

83.42 
4.11 

8.68 

2.37 
0.39 
1.03 

Nitrogenous    matter,    insolu- 
ble in  alcohol     

Nitrogenous  matter,  soluble  in 

Fat  

Inorganic  matter  or  ash  .    .    . 

Percentage    of    moisture     in 
bread  when  new    

44.09 

19.19 

41.52 

16.48 

42.02 

22.92 

41.98 

20.02 

Analyses  and  Adulteration  of  Foods,  p.  131. 


BREAD-MAKING.  263 

2.  CRACKERS  AND  HARD  BISCUIT  are  made  from  a  dough  composed 
of  flour  and  water,  with  the  addition  in  special  cases  of  a  great  variety 
of  sweetening  and  flavoring  ingredients,  such  as  milk,  eggs,  sugar,  butter 
or  lard,  spices,  and  flavoring  essences.  The  dough  prepared  in  large 
masses  is  passed  between  rollers,  and  from  the  sheet  of  dough  so  obtained 
by  other  machines  are  cut  out  the  various  forms  desired.  Sheets  or  trays 
of  these  dough-forms  pass  by  automatic  machinery  into  and  through 
long  ovens  at  a  regulated  rate  of  speed,  which  can  be  so  controlled  as  to 
give  them  exactly  the  requisite  exposure  to  the  heat  needed  for  baking. 

IV.  Analytical  Tests  and  Methods 

1.  FOR  THE  FLOUR. — The  moisture  is  determined  by  drying  five 
grammes  of  the  flour  in  a  water-oven  until  constant  weight  is  obtained. 

The  starch  is  estimated  from  the  amount  of  glucose  which  is  pro'duced 
from  it  by  the  action  of  dilute  acid.  Two  grammes  of  the  flour  are  boiled 
in  a  flask  with  inverted  condenser  for  several  hours  with  some  twenty 
cubic  centimetres  of  sulphuric  acid  suitably  diluted.  When  the  conver- 
sion of  the  starch  is  completed  the  solution  is  neutralized  with  soda,  made 
up  to  definite  volume  with  water,  and  the  glucose  determined  with  Feh- 
ling's  solution  either  gravimetrically  or  volumetrically,  as  described 
under  glucose.  (See  p.  175.)  After  deduction  of  the  sugar  found  in  a 
previous  test  to  be  contained  in  the  sample,  the  difference  is  the  amount 
produced  from  the  starch,  together  with  a  small  quantity  from  the  dex- 
trine and  traces  of  fibre.  One  hundred  parts  of  glucose  correspond  to 
ninety  of  the  starch. 

To  determine  the  cellulose,  a  weighed  quantity  of  the  flour  is  boiled 
with  rather  dilute  sulphuric  acid  for  ten  minutes  to  dissolve  the  starch. 
A  large  quantity  of  water  is  then  added,  and  the  undissolved  part  allowed 
to  settle.  The  residue  is  thrown  upon  a  filter,  well  washed  with  boiling 
water,  and  then  digested  with  dilute  potash  solution  to  dissolve  the 
albuminous  matter.  It  is  then  washed  upon  a  tared  filter,  dried,  and 
weighed.  It  is  now  incinerated  and  the  ash  determined.  This  subtracted 
from  the  weight  of  material  on  the  tared  filter  gives  the  cellulose  or  fibre. 

To  determine  the  sugar,  ten  grammes  of  the  flour  or  powdered  grain 
are  repeatedly  digested  in  alcohol  of  seventy  per  cent,  and  the  filtrate 
made  up  to  a  bulk  of  three  hundred  cubic  centimetres.  This  solution  is 
first  tested  directly  for  glucose,  but  generally  with  negative  results.  A 
known  portion  of  the  filtrate  is  then  boiled  for  four  minutes  with  five 
cubic  centimetres  of  normal  sulphuric  acid,  neutralized  with  soda  and. 
tested  with  Fehling's  solution,  and  the  sugar  present  reckoned  as  cane  is 
calculated  from  the  result. 

The  total  nitrogenous  compounds,  and  the  portions  soluble  or  in- 
soluble in  alcohol,  are  generally  determined.  The  total  nitrogen  is  deter- 
mined by  the  Gunning  or  Kjeldahl  method  and  the  nitrogen  figure  mul- 
tiplied by  5.70  for  wheat  flour.  For  the  alcohol  soluble  proteid  ten 
grammes  of  the  flour  are  completely  exhausted  with  eighty  per  cent, 
alcohol  at  a  temperature  of  140°  F.  (60°  C.)  and  an  aliquot  portion  of 


264 


FERMENTATION  INDUSTRIES. 


FIG.  68. 


150 


iflo 


the  total  filtrate  evaporated  to  dryness  and  weighed.  A  known  quantity 
of  this  residue  is  then  analyzed  for  nitrogen  by  the  Kjeldahl  or  Gunning 
process,  using  the  same  factor  5.70  as  before.  The  flour  left  after  treat- 
ment with  alcohol  is  dried,  and  a  weighed  portion  analyzed  for  nitrogen 
and  similarly  calculated  for  albuminoids  (albumen  and  fibrin). 

The  gluten  is  best  determined  as  recommended  by  Wanklyn  and 
Cooper.*  Ten  grammes  of  the  flour  are  mixed  on  a  porcelain  plate  with 
four  cubic  centimetres  of  water  so  as  to  form  a  compact  dough.  This 
is  placed  in  a  conical  test-glass  or  measure,  fifty  cubic  centimetres  of 
water  added,  and  the  dough  manipulated  with  a  spatula  so  as  to  free  it 
from  starch.  The  water  is  decanted  off,  a  fresh  quantity  added,  and  the 
kneading  continued  until  the  water  remains  colorless.  The  gluten  mass 

is  then  removed,  kneaded  in  a 
little  ether,  and  spread  out  in  a 
thin  layer  on  a  platinum  dish, 
where  it  is  dried  by  the  aid  of 
a  water-oven  until  the  weight  is 
constant.  The  crude  gluten 
contains  ash  equal  to  about  .3 
per  cent,  of  the  flour  and  fat 
equivalent  to  1.00  of  the  flour. 

An  examination  of  the  crude 
gluten  as  to  its  power  of  dis- 
tending under  the  influence  of 
heat  is  often  made  as  a  means 
of  judging  of  the  value  of  a 
flour  for  bread-making.  This 
is  done  by  the  aid  of  the  aleur- 
ometer  of  Boland,  shown  in  Fig. 
68.  Some  thirty  grammes  of  the 
flour  are  kneaded  as  just  de- 
scribed, and  seven  grammes  of 

the  freshly-separated  crude  gluten  obtained  is  placed  in  the  inner  vessel 
as  shown  at  a  b.  In  the  mean  time,  while  the  gluten  is  being  prepared, 
the  tube  D  is  heated  by  means  of  an  oil-bath  until  the  thermometer  T, 
which  is  at  first  sunk  in  the  tube  J>,  registers  150°  C.  The  thermometer 
is  then  withdrawn,  and  the  aleurometer  E,  containing  the  gluten,  put 
in  its  place.  The  spirit  lamp  under  the  oil-bath  is  allowed  to  burn  for 
ten  minutes  longer  and  then  extinguished.  The  piston  G  is  graduated 
so  that  when  pushed  down  it  registers  25°.  When  the  gluten  swells  and 
fills  the  space  from  a  &  to  c  d  it  touches  the  bottom  of  the  piston  and  is 
at  25°.  If  it  continues  to  swell  the  reading  may  be  30°  or  35°,  as  shown 
on  the  scale  when  the  piston  is  pushed  up.  If  the  gluten  does  not  indi- 
cate at  least  25°  on  the  aleurometer  it  may  be  considered  unfit  for  bread- 
making.  A  similar  instrument,  termed  an  aleuroscope,  has  been  invented 
by  Sellnick. 

To  determine  the  fat  of  the  flour,  four  grammes  are  dried  and  re- 

*  Bread   Analysis,   London,    1880,   p.    43. 


BREAD-MAKING.  265 

peatedly  digested  with  ether  until  exhausted.  The  filtrates  are  evap- 
orated in  a  tared  vessel  and  weighed. 

To  determine  the  ash,  ten  grammes  of  the  flour  are  incinerated  in  a 
platinum  capsule  to  a  white  ash,  which  is  then  weighed. 

Among  the  adulterations  of  flour,  besides  the  admixture  of  other 
starchy  material  of  lesser  value,  which  must  be  looked  for  with  the  micro- 
scope (see  starches,  p.  185),  the  most  frequently  occurring  is  alum.  For 
the  detection  of  this,  one  of  the  best  known  tests  is  based  upon  the  prop- 
erty of  alumina  of  forming  a  violet-  or  lavender-colored  lake  with  the 
coloring  matter  of  logwood.  Ten  grammes  of  the  flour  should  be  mixed 
in  a  wide  beaker  with  ten  cubic  centimetres  of  water,  one  cubic  centi- 
metre of  the  logwood  tincture  (five  grammes  of  logwood-chips  digested 
with  one  hundred  cubic  centimetres  of  strong  alcohol)  and  an  equal 
measure  of  a  saturated  aqueous  solution  of  ammonium  carbonate  are 
then  added,  and  the  whole  mixed  together  thorough^.  If  the  flour  is 
pure,  a  pinkish  color,  gradually  fading  to  a  dirty  brown,  is  obtained; 
whereas  if  alum  be  present,  the  pink  is  changed  to  a  lavender  or  actual 
blue.  As  a  precaution,  it  is  desirable  to  set  the  mixture  aside  for  a  few 
hours  or  to  warm  the  paste  in  the  water-oven  for  an  hour  or  two  and  note 
whether  the  blue  color  remains. 

To  determine  whether  flour  has  been  bleached  with  nitrogen  peroxide 
or  not,  two  tests  have  been  employed.  The  first  is  to  shake  up  twenty- 
five  grammes  of  the  flour  in  a  four-ounce  wide-mouthed  glass-stoppered 
bottle  with  gasoline.  After  the  latter  has  settled,  if  the  flour  had  been 
unbleached  the  gasoline  will  show  distinctly  yellow;  if  bleached,  it  will 
remain  nearly  colorless. 

The  second  test  is  with  the  reagents,  sulphanilic  acid  and  alpha-naph- 
thylamine  chloride  solutions,  used  to  detect  nitrites  in  water  analysis. 
Ten  grammes  of  the  flour,  one  hundred  cubic  centimetres  of  distilled 
nitrite-free  water,  and  four  cubic  centimetres  of  each  of  the  reagents  are 
shaken  up  in  a  wide-mouthed,  glass-stoppered  bottle.  With  bleached 
flour  a  pink  or  red  tint  will  be  developed.  For  the  quantitative  deter- 
mination of  nitrites  in  flour,  this  latter  test,  known  as  the  Griess-Ilosvay 
reaction,  is  carried  out  with  special  precaution,  and  the  results  compared 
with  those  obtained  from  a  standard  sodium  nitrite  solution.  (See 
Leach,  Food  Inspection  and  Analysis,  2d  ed.,  p.  321). 

2.  FOE  BREAD. — The  methods  just  described  under  flour  are  almost 
all  equally  applicable  to  the  baked  bread.  To  test  bread  for  adulteration 
from  alum  a  slightly  different  procedure  is  to  be  followed.  To  about  a 
wineglassful  of  water  in  a  porcelain  capsule  five  cubic  centimetres  of 
freshly-prepared  tincture  of  logwood  and  the  same  quantity  of  the 
carbonate  of  ammonia  solution  are  added.  A  piece  of  the  crumb  of  the 
bread,  say  about  ten  grammes,  is  then  soaked  therein  for  about  five 
minutes,  after  which  the  liquid  is  poured  away  and  the  bread  is  dried 
at  a  gentle  heat.  If  alum  be  present  the  bread  will  acquire  a  lavender 
color  or  more  or  less  approaching  dark  blue,  according  to  the  quantity  of 
the  alum  which  has  been  added;  whereas  if  the  color  be  a  dirty  brown, 
the  bread  may  be  regarded  as  pure. 


266  FERMENTATION  INDUSTRIES. 

F.  THE  MANUFACTURE  OF  VINEGAR. 

Under  the  general  heading  of  fermentation  mention  was  made  of  the 
acetic  fermentation,  which  frequently  follows  the  alcoholic  fermentation. 
It  is  produced,  it  is  true,  by  other  species  of  ferments,  but  largely  upon 
materials  susceptible  to  the  alcoholic  fermentation  or  already  changed 
by  it  into  alcohol-containing  products.  The  close  association  in  nature 
of  these  two  changes  is  readily  understood  when  the  chemical  relation- 
ship of  alcohol  and  acetic  acid  is  looked  at.  The  latter  is  the  simple 
oxidation  product  of  the  former,  and  the  processes  for  developing  the 
alcoholic  change  in  any  sugary  liquid,  such  as  a  beer-wort  or  a  grape- 
must,  have  to  be  controlled  carefully  that  they  do  not  allow  of  this  sup- 
plementary change  whereby  the  alcohol  goes  over  into  acetic  acid.  The 
conditions  under  which  the  acetic  fermentation  sets  in  may  be  sum- 
marized as  follows : 

1.  A  liquid  weak  in  alcohol,  containing  not  more  than  twelve  per 
cent,  by  weight  of  this  compound. 

2.  Abundant  access  of  air. 

3.  A  temperature  of  from  20°  to  35°  C.  (OS0  to  95°  F.). 

4.  Acetic  ferments   (Mycoderma  aceti,  etc.),  together  with  the  food 
necessary  for  these  organisms.     Under  this  heading  of  acetic  ferments 
Nageli  distinguishes  besides  the  Mycoderma  aceti,  the  Mycoderma  cere- 
visi(B  and  Mycoderma  vini,  although  the  latter  of  these  is  said  by  De 
Seynes  to  arrest  the  growth  of  the  acetic  ferment  proper.     Hansen  also 
mentions  a  second  ferment  as  found  at  times  in  beer  along  with  the 
Mycoderma,  or,  as  it  is  often  termed  now,  Bacterium  aceti,  to  which  he 
gives  the  name  Bacterium  Pasteurianum. 

The  acetic  ferment,  as  before  stated  (see  p.  203),  develops  not  by  the 
budding  process  characteristic  of  the  yeast  ferment,  but  by  splitting  or 
fissure  of  the  elongated  cell.  When  these  germs,  which  originally  drop 
from  the  air,  like  the  yeast-cells,  into  the  fermenting  or  sugary  liquids, 
find  a  liquid  specially  suited  for  their  growth,  as,  for  example,  a  mixture 
of  wine  and  vinegar,  they  develop  rapidly  over  the  surface  of  the  liquid, 
where  they  have  the  necessary  oxygen  supply,  and  form  a  gelatinous 
skin,  which  thickens  and  falls  to  the  bottom  of  the  vessel  because  of  its 
increasing  weight.  Another  skin  forms  at  once  again,  and  this  in  turn 
is  replaced  by  a  third,  and  so  on  until  the  liquid  is  completely  exhausted 
of  assimilable  material.  This  skin,  called  the  "mother  of  vinegar,"  con- 
sists of  a  multitude  of  these  minute  fissure  ferments. 

I.  Raw  Materials. 

Only  such  materials  will  be  considered  here  as  give  rise  to  a  vinegar 
by  the  normal  acetic  fermentation.  The  manufacture  of  acetic  acid  and 
technically  important  acetates  will  be  spoken  of  later  under  pyroligneous 
acid  as  derived  from  the  destructive  distillation " of  wood. 

The  materials  referred  to  as  furnishing  vinegar  under  the  influence 
of  the  acetic  fermentation  are,  first,  wine;  second,  spirits;  third,  malt- 
wort  or  beer;  fourth,  fermented  fruit  juices  other  than  wine;  and,  fifth, 
sugar-beets. 


THE    MANUFACTURE    OF   VINEGAR.  267 

The  wines  used  are  both  red  and  white  wines,  and  are  such  as  are  of 
inferior  vintages,  and  considered  unfit  for  drinking  as  wine.  Such  wines 
are  gathered  together  from  all  sections  and  are  made  into  vinegar  largely 
in  France  at  Orleans  and  at  Paris.  The  wines  do  not  exceed  ten  per 
cent,  alcoholic  strength.  Wines  about  a  year  old  are  the  best  for  vinegar- 
making,  as  the  new  wines  are  prone  to  undergo  putrid  or  ropy  fermenta- 
tion, and  older  wines  do  not  contain  sufficient  extractive  matter. 

The  spirits  used  are  chiefly  the  potato  brandy  of  Germany  and  whiskey 
in  this  country,  the  vinegar  in  either  case  being  made  by  the  "quick- 
vinegar  "  process.  These  spirits,  when  used  for  vinegar-making,  are  so 
diluted  with  water  and  vinegar  already  formed  that  the  alcoholic 
strength  ranges  between  three  and  ten  per  cent. 

The  malt-wort  used  for  vinegar-making  is  exactly  like  that  prepared 
for  grain  spirit  manufacture,  unmalted  grain  and  malt  being  used  ad- 
mixed, and  the  alcoholic  fermentation  being  pushed  so  as  to  produce  the 
maximum  amount  of  alcohol  from  the  converted  starch  of  the  grain. 
When  the  alcoholic  fermentation  is  completed  it  is  allowed  to  stand  for 
some  days  in  the  fining- vats,  where  all  dead  yeast  and  cloudiness  subside, 
and  it  is  then  made  to  pass  through  a  filter-bed  of  wood-chips  into  the 
acetifier.  The  unmalted  grain  used  in  the  preparation  of  the  wort  must 
be  thoroughly  dried  in  a  kiln  previous  to  crushing  in  order  that  many 
of  the  glutinous  and  albuminoid  matters  may  be  destroyed.  These  would 
otherwise  interfere  with  the  keeping  qualities  of  the  vinegar.  Sour  ale 
or  beer  is  said  not  to  yield  good  vinegar,  but  a  product  very  liable  to 
undergo  putrid  fermentation,  a  very  disagreeable  smell  being  imparted 
to  the  vinegar  in  consequence. 

Cider  from  apples  and  Perry  from  pears  are  about  the  only  fruit 
juices  besides  wine  fermented  for  the  production  of  vinegar.  Cider  from 
good,  sweet,  and  ripe  apples  serves  for  the  manufacture  of  cider  vinegar 
in  this  country.  The  cider  is  the  product  of  a  spontaneous  alcoholic  fer- 
mentation of  the  apple  juice,  and  the  vinegar  formation  may  be  merely 
a  continuation  of  this  spontaneous  change,  but  much  is  now  made  by  the 
quick-vinegar  process,  using  casks  containing  beechwood  shavings. 

Sugar-beets  are  used  somewhat  in  France  for  vinegar-making.  The 
beets  are  rasped  to  a  fine  pulp  and  pressed.  The  juice  is  diluted  with 
water  and  boiled.  After  cooling,  yeast  is  added  and  the  alcoholic  fer- 
mentation developed,  and  this  product  mixed  with  vinegar  and  treated 
as  the  other  alcoholic  liquids  before  mentioned  for  the  development  of 
the  acetic  fermentation. 

Artificial  glucose,  cane-sugar,  and  molasses  have  also  been  used  in 
England  for  the  production  of  vinegars  which  are  used  to  adulterate 
malt  vinegar. 

n.  Processes  of  Manufacture. 

1.  THE  ORLEANS  PROCESS. — This  is  the  process  by  which  wine  vine- 
gar is  made  in  France  and  Germany,  and  is  the  oldest  in  practical  use 
of  the  several  methods  now  employed.  The  wine  which  is  to  be  acetified 
is  allowed  to  stand  for  a  time  over  wine-lees,  and  then  clarified  by  being 
passed  through  vats  containing  beech-shavings.  The  oaken  acetifying 


268  FERMENTATION  INDUSTRIES. 

vessels,  holding  from  fifty  to  one  hundred  gallons,  known  as  "mother- 
casks,  ' '  are  first  steamed  out  and  then  soured  with  boiling  vinegar,  which 
is  made  to  fill  one-third  of  the  cask.  The  wine  is  now  added  in  instal- 
ments of  ten  litres  every  eight  days  until  the  cask  has  become  more  than 
half-full,  when  one-third  of  its  contents  are  siphoned  off  into  storage- 
vats  and  the  periodical  addition  of  wine  continued  as  before.  The 
"mother-casks,"  or  acetifiers,  can  be  used  in  this  way  continuously  for 
years  until  the  sediment  of  yeast,  argols,  and  impurities  makes  it  neces- 
sary to  give  them  a  thorough  cleaning.  The  vinegar  obtained  in  this  way 
has  a  very  agreeable  aroma,  that  made  from  white  wines  being  most 
esteemed.  When  the  wines  employed  in  the  Orleans  process  are  too 
weak  it  often  happens  that  the  vinegar  is  ropy  and  wanting  in  trans- 
parency. In  such  case  it  must  undergo  the  firing  process.  The  progress 
of  the  acetification  is  judged  of  by  plunging  in  a  rod  and  examining  the 
froth  upon  it  when  withdrawn.  This  should  be  white  and  copious.  The 
temperature  that  is  found  to  answer  best  is  between  24°  and  26.6°  C. 
(75°  and  80°  F.) 

Hengstenberg  has  proposed  a  modification  of  the  Orleans  process, 
whereby  a  series  of  the  "mother-casks  "  are  connected  together  at  the 
base  by  short  pieces  of  glass  tubing.  After  the  acetification  of  the  first 
addition  of  wine  in  each  cask  the  new  wine  is  added  only  to  the  first 
cask,  into  which  it  runs  slowly,  while  from  the  last  cask  of  the  series, 
by  means  of  a  siphon-tube  fixed  in  the  side,  the  excess  flows  off  as  finished 
vinegar.  The  increase  of  yield  by  this  modification  is,  however,  only 
slight. 

2.  THE  QUICK-VINEGAR  PROCESS. — This  process  was  first  introduced 
by  Schutzenbach  in  1823,  and  has  been  considerably  improved  since.  It 
is  used  exclusively  in  the  case  of  spirit  vinegar  in  Germany  and  in  this 
country,  and,  with  slight  modifications,  in  England  for  malt  vinegar. 
The  vinegar-formers  are  upright  casks  from  six  to  twelve  feet  in  height 
and  three  to  five  feet  in  diameter.  About  a  foot  above  the  true  bottom 
of  the  cask  it  has  a  false  bottom  perforated  like  a  sieve.  Upon  this 
beech-wood  shavings  are  heaped,  extending  nearly  to  the  top  of  the  cask. 
Between  the  true  and  false  bottoms  and  just  under  the  latter  a  series  of 
holes  is  bored  in  the  cask  in  a  direction  slanting  downward  and  extend- 
ing around  the  entire  cask.  The  beech-shavings  are  first  boiled  in  water 
and  dried.  They  are  then  soured  or  soaked  in  warm  vinegar  for  twenty- 
four  hours,  filled  into  place  and  covered  by  a  wooden  disk  perforated 
by  fine  holes  in  which  pack-thread  is  loosely  filled.  This  disk  also  is 
perforated  by  four  larger  glass  tubes  open  at  both  ends,  which  serve  as 
air- vents.  The  cask  is  then  closed  on  top  by  a  wooden  cover  with  a  single 
hole  in  the  centre,  through  which  the  alcoholic  liquid  is  to  be  poured  and 
from  which  air  may  escape.  The  entire  arrangement  may  be  understood 
from  Fig.  69.  During  the  oxidation  of  the  alcoholic  liquid  considerable 
heat  is  developed,  and  a  current  of  air  is  thus  made  to  enter  through 
the  circle  of  holes  under  the  false  bottom  and  rise  through  the  wet  shav- 
ings, escaping  through  the  opening  at  the  top.  The  diluted  spirits  or 
mixture  to  be  acetified  are  poured  into  the  top  of  each  vat,  and  as  they 


THE  MANUFACTURE  OF    VINEGAR. 


269 


flow  off,  by  the  aid  of  a  siphon  arrangement  from  the  base  they  are  intro- 
duced into  the  top  of  the  second  vat.  If  not  over  four  per  cent,  of  alco- 
hol were  contained  in  the  original  liquid,  that  drawn  off  from  the  second 
vat  will  be  converted  into  good  vinegar.  The  temperature  of  the  vinegar- 
forming  casks  should  be  about  35°  C.  (95°  F.).  Above  this  there  is  too 
much  loss  of  alcohol  and  aldehyde  by  evaporation;  below  it,  the  oxida- 
tion goes  too  slowly.  If  the  minute  organisms  known  as  "vinegar  eels  " 
show  themselves,  hot  vinegar  is  poured  in  on  top  until  it  shows  a  temper- 
ature of  50°  C.  (122°  F.)  on  running  off,  which  kills  them. 

FIG.  69. 


Whiskey,  brandy,  and  grain  spirit  properly  diluted  are  all  acetified 
by  the  aid  of  this  quick-vinegar  process.  To  these  diluted  spirits  a 
small  amount  of  malt  infusion  is  generally  added  to  furnish  nutritive 
matter  for  the  development  of  the  acetic  ferment,  which  in  this  process 
as  in  the  preceding  is  the  agency  whereby  the  atmospheric  oxidation 
becomes  effective  in  changing  alcohol  into  acetic  acid. 

3.  MANUFACTURE  OF  MALT  VINEGAR. — This  is  effected  by  a  process 
much  resembling  the  quick-vinegar  process.  The  acetifiers  are,  however, 
much  larger,  holding  from  eight  thousand  to  ten  thousand  gallons.  Their 
construction  is  shown  in  Fig.  70.  Bundles  of  birch-twigs,  B,  are  sup- 
ported upon  a  perforated  bottom,  from  which  the  liquid  trickles  in  fine 
streams.  The  malt-wort  fed  in  below  is  warmed  by  a  closed  steam-coil 
of  block-tin,  and  pumped  to  the  top  of  the  casks,  where  it  is  sparged,  or 


270  FERMENTATION  INDUSTRIES. 

sprinkled,  in  fine  streams  over  the  birch-twigs,  and  the  process  repeated 
until  the  vinegar  shows  the  requisite  strength.  These  birch-twigs  have 
been  previously  freed  from  all  juice  and  coloring  matter  by  repeated 
boiling  with  water,  and  are  soured  before  starting  the  sparging.  The 
entire  process  of  making  malt  vinegar  requires  about  two  months.  The 
temperature  at  the  beginning  of  the  process  is  about  43°  C.  (110°  F.), 
and  later  is  kept  at  38°  C.  (100°  F.). 

4.  THE  MANUFACTURE  OF  CIDER  VINEGAR. — As  before  stated,  this  is 
largely  a  spontaneous  fermentation.     The  fresh  cider  is  allowed  to  fer- 
ment in  barrels  having  the  bung-hole  open,  which  are  exposed  to  the 
sun  or  placed  in  a  warm  cellar.     The  acetification  is  often  made  a  pro- 
gressive change  by  adding  fresh  quantities  of  cider  to  the  barrel  every 
few  weeks;  the  addition  of  "mother  of  vinegar  "  also  is  made  to  accel- 
erate the  change. 

5.  PASTEUR'S  PROCESS  FOR  VINEGAR-MAKING  BY  DIRECT  USE  OF  THE 
VINEGAR  FUNGUS. — Pasteur  takes  an  aqueous  liquid  containing  two  per 
cent,  of  alcohol  and  one  per  cent,  of  vinegar  and  small  amounts  of  phos- 
phates of  potassium,  magnesium,  and  lime,  and  in  this  propagates  the 
acetic  ferment    (Mycoderma  aceti).     The  plant  soon  spreads  out  and 
covers  the  whole  surface  of  the  liquid,  at  the  same  time  acetifying  the 
alcohol.    When  one-half  of  the  alcohol  has  been  changed  small  quantities 
of  wine  or  alcohol  mixed  with  beer  are  added  daily  until  the  acetification 
slackens,  when  the  vinegar  is  drawn  off  and  the  "mother  of  vinegar  " 
collected,   washed,    and   used   again   with   a   freshly-prepared   mixture. 
When  wine  or  beer  is  used,  the  addition  of  the  phosphate  salts  as  food 
for  the  plant  is  unnecessary,  but  when  pure  alcohol  is  used  they  are 
needed.     Vinegar  prepared  by  this  process  is  said  to  possess  the  agree- 
able aroma  of  wine  vinegar. 

m.  Products. 

Wine  Vinegar  varies  in  color  from  light  yellowish  to  red,  according 
as  it  has  been  derived  from  white  or  red  wines,  that  from  the  former 
being  the  most  highly  esteemed.  The  vinegar  from  red  wines,  however, 
can  be  decolorized  by  filtration  through  purified  bone-black.  Skimmed 
milk  is  also  used  for  the  same  purpose.  When  thoroughly  agitated  with 
the  vinegar  the  casein  coagulates  and  carries  down  with  it  the  greater 
part  of  the  coloring  matter  of  the  vinegar,  besides  clarifying  it.  It  is 
not  used,  however,  so  much  as  the  filtration  through  charcoal.  Wine 
vinegar  has  a  specific  gravity  1.014  to  1.022,  and  contains  from  six  to 
nine  per  cent,  (rarely  twelve)  of  absolute  acetic  acid.  When  freshly 
made,  it  contains  traces  of  alcohol  and  aldehyde.  The  amount  of  acid 
potassium  tartrate  (tartar)  contained  in  wine  vinegar  averages  .25  per 
cent.  Its  presence  is  peculiar  to  this  variety  of  vinegar. 

Malt  and  Beer  Vinegars  have  a  higher  specific  gravity  (1.021  to 
1.025)  and  contain  dissolved  dextrine,  maltose,  soluble  albuminoids,  and 
similar  constituents  of  the  malt  extract.  This  kind  of  vinegar  on  evap- 
oration leaves  a  glutinous  residue  only  sparingly  soluble  in  alcohol.  It 
contains  from  three  to  six  per  cent,  of  acetic  acid. 


THE  MANUFACTURE  OF    VINEGAR.  271 

Spirit  Vinegar  is  colorless  as  produced,  but  is  frequently  colored  with 
caramel-color  to  imitate  the  appearance  of  wine  or  cider  vinegar.  It 
contains  from  three  to  eight  per  cent,  of  acetic  acid,  although  the  so- 
called  "vinegar  essence  "  (double  vinegar)  may  contain  as  much  as 
fourteen  per  cent. 

Cider  Vinegar  is  yellowish-brown,  has  an  odor  of  apples,  a  density 
of  1.013  to  1.015,  and  contains  from  three  and  a  half  to  six  per  cent,  of 
acetic  acid.  It  is  distinguished  from  the  other  varieties  by  yielding  on 
evaporation  a  mucilaginous  extract  smelling  and  tasting  of  baked  apples 
and  containing  malic  acid,  which  replaces  the  tartaric  acid  of  the  wine 
vinegar.  The  differences  between  cider  vinegar  and  whiskey  vinegar  as 
manufactured  in  this  country  are  shown  in  the  accompanying  analyses 
by  Battershall :  * 

Cider  vinegar.  Whiskey  vinegar. 

Specific  gravity    1.0168  1.0107 

Specific  gravity  of  the  distillate  from 

neutralized  sample    0.9985  0.9973 

Acetic  acid    4.66  7.36 

Total  solids   2.70  0.15 

Total  ash   0.20  0.038 

Potassa  and  phosphoric  acid  in  ash .  .        Considerable.  None. 

Heated  with  Fehling's  solution Copious  reduction.  No  reduction. 

Treated  with  basic  lead  acetate Flocculent  precipitate.  No  precipitate. 

Glucose,  or  Sugar,  Vinegar,  prepared  from  different  saccharine  and 
amylaceous  materials  by  conversion  with  dilute  acid,  followed  by  fermen- 
tation and  acetification,  contains  dextrose,  dextrine,  and  often  calcium 
sulphate  (from  commercial  glucose).  It  is  said  to  be  employed  in  France 
and  England  for  adulterating  wine  or  malt  vinegars. 

Factitious  Vinegars  are  often  made  from  pyroligneous  acid  flavored 
with  acetic  ether  and  colored  with  caramel-color.  Such  a  product  differs 
from  malt  vinegar  in  containing  no  phosphates,  and  from  wine  or  cider 
vinegar  in  the  absence  of  tartaric  or  malic  acids  respectively. 

IV.  Analytical  Tests  and  Methods. 

The  determination  of  the  acetic  acid  is  usually  done  by  titration  with 
standard  alkali,  using  phenolphthalei'n  as  indicator.  In  the  presence  of 
free  sulphuric  acid,  it  is  necessary  to  distil  a  measured  quantity  of  the 
sample  almost  to  dryness  and  titrate  the  distillate,  it  being  assumed 
that  eighty  per  cent,  of  the  total  acetic  acid  present  passes  over. 

The  determination  of  the  extract  or  solid  residue  in  vinegar  is  exe- 
cuted in  the  same  manner  as  described  under  beer  or  wine. 

The  test  for  sulphuric  acid  is  an  important  one.  In  England,  the 
manufacturers  were  allowed  by  law  to  add  one  part  of  sulphuric  acid  by 
volume  to  one  thousand  of  vinegar  in  order  to  protect  weak  vinegar  from 
the  putrid  fermentation.  This  addition  is  not  necessary  in  good  vinegar 
and  is  not  generally  followed  at  present.  Still,  it  may  be  present,  and 
is  to  be  looked  for  in  all  vinegars.  The  usual  test  with  basic  chloride  is 

*  Food  Adulteration  and  Detection,  New  York,  1887,  p.  230. 


272  FERMENTATION  INDUSTRIES. 

inoperative  here,  as  sulphates  may  be  present  in  the  vinegar  from  the 
water  used,  etc.  Hehner's  test  for  free  mineral  acids  (sulphuric  and 
hydrochloric),  now  regarded  as  satisfactory  in  this  case,  is  based  on  the 
fact  that  acetates  and  most  other  salts  of  organic  acids  are  decomposed 
by  ignition  into  carbonates,  having  an  alkaline  reaction  to  litmus,  while 
sulphates  and  chlorides  of  the  light  metals  are  unchanged  on  ignition 
and  possess  a  neutral  reaction.  To  determine  the  amount  of  free  mineral 
acid  it  is  sufficient  therefore  to  carefully  neutralize  the  vinegar  with 
standard  solution  of  soda  before  evaporation  to  dryness  (the  same  process 
serving  for  a  determination  of  the  total  free  acid),  ignite  the  residue, 
and  titrate  the  aqueous  solution  of  the  ash  with  standard  acid.  If  the 
free  acid  originally  present  were  wholly  organic,  the  ash  will  contain  an 
equivalent  amount  of  alkaline  carbonate,  which  will  require  an  amount 
of  standard  acid  for  its  neutralization  exactly  equivalent  to  the  amount 
of  standard  alkali  originally  added  to  the  vinegar.  Any  deficiency  in 
the  amount  of  standard  acid  required  for  neutralization  is  due  to  the 
free  mineral  acid  originally  present  in  the  vinegar. 

The  tartaric  acid,  a  normal  constituent  of  wine  vinegar,  may  be  tested 
for  by  evaporating  to  dryness  and  treating  the  extract  with  alcohol, 
which  dissolves  nearly  everything  but  the  tartar  or  acid  potassium  tar- 
trate.  On  pouring  off  the  alcohol  and  dissolving  this  in  a  little  hot  water 
its  nature  can  be  easily  shown  by  the  usual  tests  for  tartaric  acid. 

Caramel  is  recognized  by  extracting  the  solid  residue  with  alcohol  and 
evaporating  the  solution  to  dryness;  in  its  presence  the  residue  now 
obtained  will  possess  a  decidedly  dark  color  and  a  bitter  taste. 

Metallic  impurities,  such  as  lead,  copper,  and  zinc,  are  at  times  to  be 
found  arising  from  the  use  of  metallic  vessels  for  storing  the  vinegar. 
Arsenic  has  also  been  found  as  an  impurity  through  the  use  of  impure 
sulphuric  or  hydrochloric  acid.  They  are  all  detected  by  the  usual 
qualitative  tests. 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

OF   FERMENTATION    AND    ITS    INDUSTRIES    IN    GENERAL. 

1879. — Studies  on   Fermentation,  M.   Pasteur,   translated  by  Faulkner  and   Robb, 

London. 
Theorie  der  Giihrurig,  C.  von  Nageli,  Miinchen. 

1883. — The  Brewer,  Distiller,  and  Wine  Manufacturer,  J.  Gardner,  Philadelphia. 

1884. — Falsifications  des  Mati&res  alimentaires,  Laboratoire  Municipal,  2e  Rapport, 
Paris. 

1887. — United  States  Department  of  Agriculture,  Bulletin  No.   13,  Part  iii.    (Fer- 
mented Alcoholic  Beverages),  C.  A.  Crampton,  Washington. 
Fermentation,  P.  Schiitzenberger    (Inter.  Science  Series),  New  York. 

1889. — Les  Fermentations,  E.  Bourguelot,  Paris. 

Chemie  der  menschlichen  Nahrungsmittel,  J.  Konig,  3te  Auf.,  Berlin. 

1892. — Untersuchungen  aus  der  Praxis  der  Gahrungs-Industrie,  E.  Ch.  Hansen,  zwei 
Hefte,   Miinchen. 

1893. — Micro-organisms  and  Fermentation,  A.  Jorgensen,  translated  by  A.  K.  Miller 
and  E.  A.  Lennholm,  London. 

1896. — Practical  Studies  in  Fermentation,  E.  Ch.  Hansen,  translated  by  A.  K.  Miller, 
New  York. 


BIBLIOGRAPHY  AND  STATISTICS.  273 

1898. — Technical  Mycology,  the  Utilization  of  Micro-organisms,  etc.,  F.  Lafar,  trans- 
lated by  Chas.  T.  C.  Salter,  vol.  i.,  Philadelphia. 

1899. — Les  Enzymes  et  leurs  applications,  J.  Effront,  Paris. 

The   Soluble   Ferments   and    Fermentation,   J.    Reynolds    Green,    Cambridge, 
England. 

1000. — Die  Diastasen  und   ihre   rolle   in  der   Praxis,   J.   Effront,   iibersetzt  bei   M. 
Biicheler,  Band  i.,  Leipzig. 

1905. — Abriss  der  mykologischen  Analyze,  etc.,  Bauer,  Braunschweig. 

1907. — Handbuch  der  technischen  Mykologie,  F.  Lafar,  2te  Auf.,  5  Bde.,  Jena. 

1908. — Die  Hefepilze,  Kohl,  Leipzig. 

1910. — Die  Fermente  und  ihre  Wirkungen,  C.  Oppenheimer,  3rd  Auf.,  Berlin. 

ON  MALTING  AND  BREWING  AND  THEIR  PRODUCTS. 

1876. — fitudes  sur  la  Bi&res,  ses  Maladies,  etc.,  M.  Pasteur,  Paris. 

1877. — Hops:    their  Cultivation,  Commerce,  and  Uses,  P.  L.  Simmonds,  London. 

1878. — Lehrbuch   der   Bierbrauerei,   C.   Lintner,   Braunschweig. 

1880. — Die  Fabrikation  von  Malz,  Malzextract,  and  Dextrin,  J.  Bersch,  Berlin. 

1882. — Preparation  of  Malt  and  Fabrication  of  Beer,  Thaussing,  edited  by  Schwarz 
and  Bauer,  Philadelphia  and  London. 

1884. — Handbuch  der  Bierbrauerei,  L.  von  Wagner,  6te  Auf.,  2  Bde.,  Braunschweig. 

1886.— Die  Malz-Fabrikation,  K.   Weber. 

1888. — The  Theory  and  Practice  of  Modern  Brewing,  F.  Faulkner,  2d  ed.,  London. 

1889. — Manuel  pratique  de  la  Fabrication  de  la  Biere,  P.  Boulin,  Paris. 
The  Microscope  in  the  Brewery,  Matthews  and  Lott,  London. 

1891. — Handbuch  der  Bierbrauerei,  E.  Ehrich,  5te  Auf.,  Halle. 

Text-Book  of  the  Science  of  Brewing,  edited  by  Morritz  and  G.  H.  Morris, 
London. 

1892. — Untersuchung  des  Maizes,  Windisch,  Berlin. 

1893. — La  Biere,  H.  Boucheron,  Paris. 

1894. — Die  Bierbrauerei,  Dr.  B.  von  Posanner,  Wien. 

1895. — Systematic  Book  of  Practical  Brewing,  E.  R.  Southby,  3d  ed.,  London. 

Handy-Book   for   Brewers   and   Practical   Guide  to  Malting,   H.   E.   Wright, 
2d  ed.,  London. 

1897. — The  Principles  and  Practice  of  Brewing,  W.  J.  Sykes,  London. 

1898. — The  Laboratory  Text-Book  for  Brewers,  L.  Briant,  2d  ed.,  London. 

1907. — Theorie  und  praxis  der  malzbereitung  und  bierfabrikation,  Thausing,  Leip- 
zig. 
The   Brewer's    Analyst — A    systematic   hand-book    of    analysis    of    materials 

used  for  brewing  and  malting,  R.  D.  Bailey,  London. 
Das  Chemische  Laboratorium  des  Brauers,  Wilh.  Windisch,  5th  Auf.,  Berlin. 

1908. — Hopfenbau  und  hopfenbehandlung,  Fruwirth,  Berlin. 

ON  WINKS. 

1872. — Treatise   on   the   Origin,   Nature,   and  Varieties   of  Wine,    Thudichum   and 

Dupre",  London. 
1873. — fetudes  sur  le  Vin,  ses  Maladies,  etc.,  M.  Pasteur,  2me  e"d.,  Paris. 

Die  Kiinstliche  Weinbereitung,  F.  J.  Dochnahl,  3te  Auf.,  Frankfort. 
1878. — Die  Bereitung  des  Schaumweines,  etc.,  A.  von  Regner,  Wien. 
1879. — Die  Bereitung  des  Schaumweines,  etc.,  A.  von  Regner,  Wien. 

Ueber  die  Chemie  des  Weines,  C.  Neubauer,  Wiesbaden. 

1881. — Handbuch  des  Weinbaues,  etc.,  A.  von  Babo,  2   Bde.,  Braunschweig. 
1884. — Die  Weinanalyze,  Max  Earth,  Leipzig. 

Anleitung  zur  chemischen  Analyse  des  Weines,  Eug.  Borgmann,  Wiesbaden. 

Die  Chemie  der  Rothweine,  E.  Roth,  2te  Auf.,  Heidelberg. 

A  History  of  Champagne,  H.  Vizetelly,  London. 
1888. — Die  Praxis  der  Weinbereitung,  J.  Bartsch. 

18 


274  FERMENTATION  INDUSTRIES. 

1889. — 'Manuel  de  1'Analyze  des  Vins,  E.  Barillot,  Paris. 

Chimie  des  Vins,  A.  de  Saporta,  Paris. 

Wines  and  Vines  of  California,  F.  E.  Wait,  San  Francisco. 

Practische   Anleitung    feinste   Desertweine,    etc.,    darzustellen,    L.    Gall,    4te 

Auf.,  Wien. 

1890. — Trait6    theorique   et   pratique   du   Travail    des    Vins,    2    vols.,    3me    ed.     E. 
Maumene",  Paris. 

The  Cider-Maker's  Handbook,  J.  M.   Trowbridge,  New  York. 
1891. — Sophistication  et  Analyse  des  Vins,  A.  Gautier,  4me  6d.,  Paris. 
1892. — Le  Vin  et  1'Art  de  la  Vinification,  Victor  Cambon,  Paris. 

Analyse  des  Vins,  M.  de  la  Source,  Paris. 

Die   Champagne-Fabrikation,  Adal   Piaz,   Wien. 

L'Essai  commercial  des  Vins  et  des  Vinaigres,  Dujardin,  Paris. 
1896. — Manuel  g§n6ral  des  Vins,  E.  Robinet,  5me  e"d.,  3  vols.,  Paris. 
1899. — Proce"de"s  modernes  de  Vinification,  2me  6d.,  Coste-Floret,  Montpellier. 

Trait6  pratique  d'Analyse   chimixrue  des  Vins,  J.  Roussel,  Paris. 
1905. — Lehrbuch    der    chemischen    technologie    der    landwirthchaftlichen    gewerbe, 

Ahrens,   Berlin. 
1908. — Die  Bereitung,   Pflege  und  Untersuchung  des  weines,  J.  Nessler,  8th  Auf., 

von  Carl  Windisch,  Stuttgart. 
1909. — Die  Wein  bereitung  und  Kellerwirthschaft,  by  A.  Dal  Piaz,  Wien. 

ON    SPIRITS   AND   DISTILLED    LIQUORS. 

1879. — Treatise  on  the  Manufacture  of  Alcoholic  Liquors,  P.  Duplais,  translated  by 

M.  McKennie,  Philadelphia. 

1885. — Practical  Treatise  on  the  Distillation,  etc.,  of  Alcohol,  Win.  T.  Brannt,  Phila- 
delphia. 

1886. — Die  Fabrikation  von  Rum,  Arrak,  Cognac,  etc.,  A.  Gaber,  Leipzig. 
1889. — Ueber  Branntwein,  seine  Darstellung,  etc.,  Dr.  Eugen  Sell,  Berlin. 
1890. — Ueber  Cognac,  Rum  and  Arrak,  etc.,  Dr.  Eugen  Sell,  Berlin. 

La  Fabrication  de  1'Alcool,  7  Fascicules,  J.  P.  Roux,  Paris. 
1891. — Die  Cognac  und  Weinspirit  Fabrikation,  A.  del  Piaz,  Wien. 

Untersuchungs-Methoden  der  Spiritus  Industrie,  E.  Bauer,  Braunschweig. 
1892. — Nouveau  traite"  de  la  Fabrication  des  Liqueurs,  etc.,  Fritsch  et  Fesq,  Paris. 
1893. — Les  Eaux-de-Vie  et  la  Fabrication  du  Cognac,  A.  Baudoin,  Paris. 

Manufacture  of  Liquors  and  Preserves,  J.  de  Brevans,  New  York. 

The  Manufacture  of  Spirit,  J.  A.  Nettleton,  London. 
1894. — Manuel   des   Fabricants   d'Alcools,    Barbet   et   Aracheguesne,   Paris. 

Handbuch  der  Spiritus-Fabrikation,  M.  Maercher,  6te  Auf.,  P.  Parey,  Berlin. 

Die    Spiritus-Fabrikation,    Essigerzeugung   und   Weinbereitung,    Dr.    B.    von 

Posanner,  Wien. 

1895. — La  Chimie  du  Distillateur,  M.  P.  Guichard,  Paris. 
1899. — Trait6  complet  de  la  Fabrication  de  PAlcool,  etc.,  G.  Dejaghe,  Lille. 

Les  Eaux-de-Vie  et  Liqueurs,  X.  Rocques,  Paris. 

Manuel    pratique    de    1'Analyse,  des    Alcools    et    des    Spiritueux,    Girard    et 

Cuniasse,  Paris. 
1900. — Trait6  de  la  Fabrication  des  Liqueurs  et  de  la  Distillation,  P.  Duplais,  7me 

6d.,   Paris. 
1907. — Industrial  Alcohol,  its  Manufacture  and  Uses,  J.  K.  Brachvogel,  New  York. 

Denatured  or  Industrial  Alcohol,  R.  F.  Herrick,  New  York. 

Industrial  Alcohol,  Production  and  Use,  J.  G.  Mclntosh,  London. 
1908. — Handbuch  der  spiritus-fabrikation,  M.   Maercker,   9th  Auf.,   Herausgegeben 
von  Dr.  M.  Delbruck,  Berlin. 

ON    THE   MANUFACTURE   OF   VINEGAR. 

,  1868. — fitudes  sur  le  Vinaigre,  M.  Pasteur,  Paris. 
1876. — Lehrbuch  der  Essigfabrikation,  P.   Bronner,  Braunschweig. 
1877. — Die  Essigfabrikation,  J.  C.  Leuchs,  7te  Auf. 


BIBLIOGRAPHY  AND  STATISTICS.  275 

1880. — Fabrication  industrielle  des  Vinaigres,  Claudon,  Paris. 
1885. — Acetic  Acid  and  Vinegar,  John  Gardner,  Philadelphia. 
1890. — Vinegar:  a  Treatise  on  the  Manufacture  of  Vinegar,  etc.,  Wm.  T.  Brannt, 

Philadelphia. 

1892. — L'Essai  commercial  des  Vins  et  des  Vinaigre^  Dujardin,  Paris. 
1895. — Die  Essigfabrikation,  Dr.  J.  Bersch,  4te  Auf.,  Wien. 
1907. — Die  Untersuchungs  methoden,  etc.,  des  gab. rung-ess igs,  Dr.  Fritz  Rothenbach, 

Berlin. 


ON  FLOUR  AND  BREAD. 

1878. — Das  Brodbacken,  K.  Birnbaum,  Braunschweig. 

1880. — The  Chemistry  of  Bread-Making    (Lectures  before  Society  of  Arts),  Chas. 

Graham,  London. 
1884. — Die  Fabrikation  des  Mehls  und  seine  neben  Producte,  H.  Meyer,  2  Theile, 

Leipzig. 
1886. — Bread  Analysis,  Wanklyn  and  Cooper,  2d  ed.,  London. 

United  States  Department  of  Agriculture,  Bulletins  Nos.  1,  4,  9    (American 

Cereals),  C.  Richardson,  Washington. 

The  Chemistry  of  Wheat,  Flour,  and  Bread,  W.  Jago,  Brighton. 
1889. — Handbuch  der  Presshefe-Fabrikation,  Otto  Durst,  Berlin. 

United  States  Department  of  Agriculture,  Bulletin  No.   13,  Part  v.    (Bak- 
ing-Powders ) ,  C.  A.  Crampton,  Washington. 

1890. — Presshefe,  Kunsthefe  und  Backpulver,  A.  Wilfert,  2te  Auf.,  Wien. 
1892. — Le  Pain  et  la  Viande,  J.  de  Brevans,  Paris. 

The  Dietetic  Value  of  Bread,  J.  Goodfellow,  London. 

1895. — Text-Book  of  Science  and  Art  of  Bread-Making,  W.  Jago,  London. 
1897. — Modern  Flour-Milling,  W.  R.  Voller,  3d  ed.,  Gloucester,  Eng. 

STATISTICS. 

I.      PRODUCTION  OF  HOPS  THROUGHOUT  THE  WORLD. 

From  the  U.  S.  Consular  Keports  the  total  crop  of  hops  throughout 
the  world  for  the  last  three  years  is  given  as  follows: 

TOTAL  CROP  IN  CWT.  OF   110  LBS. 

Countries                                                   1909                      1910  1911 

Germany     119,000  384,000  222,000 

Austria-Hungary     164,000  297,000  178,000 

France     27,000               54,000  45,000 

Belgium  and  Holland 29,000               58,000  52,000 

Russia     60,000               58,000  62,000 

England     205,000  296,000  354,000 

America     310,000  400,000  400,000 

Australia     10,000               10,000  15,000 


924,000          1,557,000          1,328,000 

The  United  States  imports  a  limited  quantity  of  hops,  but  exports  a 
much  larger  amount.    The  figures  for  recent  years  were : 

1906.                     1907.                  1908.                   1909.  1910. 

Imports  in  pounds    9,630,206       5,733,386       8,636,192       7,383,907  3,185,991 

Valued  at    $2,266,333     $1,813,306     $1,911,602     $1,335,300  $1,492,779 

Exports   in  pounds    ..    .    13,026,904     16,809.534     22,920,480     10,446,884  10,589,254 

Value;!  at    $3,125,843     $3,531,972     $2,963,167     §1.271.62:)  $2,002,140 


276 


FERMENTATION  INDUSTRIES. 


II.   tt.   BEEE  PRODUCTION   IN   THE   UNITED   STATES. 

According  to  the  reports  of  the  Commissioner  of  Internal  Revenue, 
there  were  brewed  in  the  United  States  the  following  amounts  of  malt 
liquors : 

Bbls.  (31  gallons 
or  117.3  litres). 

1905  49,459,540 

1906  54,724,553 

1907  58,546,111 

1908  58,747,680 

1909  56,364,360 

1910  ' 59,544,775 

II.   6.   PRODUCTION  OF  DISTILLED  SPIRITS  IN  THE  UNITED   STATES    (IN  GALLONS). 


From  grain  and 

cereals.  •         From  fruit. 

1906  145,666,125  4,444,072 

1907  168,573,913  6,138,305 

1908  126,989,740  6,899,823 

1909  133,450,755  6,440,859 

1910  156,237,526  7,656,433 


Totals. 
150,110,197 
174,712,218 
133,889,563 
139,891,613 
163,893,960 


II.   C.   BEER  PRODUCTION  AND   CONSUMPTION   OF  THE  WORLD   FOR    1904   AND    1905. 


Production 
1904. 

Great   Britain    56,395,360 

Russia     6,560,140 

Norway    295,020 

Sweden    2,751,210 

Denmark    2,451,460 

Germany     69,538,590 

Belgium     15,163,830 

France    14,125,320 

Switzerland    2,093,850 

Italy    227,700 

Austria     19,621,800 

Hungary    1,500,840 

Bulgaria     64,340 

Servia    75,240 

United    States    57,546,310 


in  hectolitres. 

1905. 
54,842,670 

307,890 

2,415,010 
72,027,450 
15,592,500 
13,283,820 

235,620 

10,908,010 

1,485,990 

88,110 

63,591,840 


Consumption  per 
capita  in  litres. 

1904. 

1905. 

129.60 

124.65 

4.54 

13.05 

13.50 

52.20 

92.25 

92.25 

115.65 

118.35 

216.90 

219.60 

34.45 

33.75 

64.35 

0.90 

0.99 

68.40 

64.35 

8.10 

8.10 

1.67 

2.21 

2.97 

68.80 

75.60 

248,410,000       245,778,910  58.25           68.48 
(English  Parliamentary  Report  on  Alcoholic  Beverages,  1905. ) 

III.   WINE  PRODUCTION  OF  THE  WORLD  FOR  1897  AND   1898. 

1S<»7.  1898. 

Hectolitres.  Hectolitres. 

France    32,350,700  32,282,300 

Algeria  and  Tunis    4,457,758  5,341,000 

Italy     25,958,500  31,500,000 

Spain    18,900,000  24,750,000 

Portugal     2,500,000  2,100,000 

Austria-Hungary     3,000,000  2,800,000 

Russia     2,500,000  3,120,000 

Switzerland    1,250,000  1,160,000 

Germany    2,775,576  1,406,818 

Roumania    3,200,000  3,900,000 

United  States   1,147,000  1,300,000 

Other  countries    10,261,000  9,975,000 

108,300,534  119,635,818 


BIBLIOGRAPHY  AND  STATISTICS.  277 

IV.   a.   CONSUMPTION   OF   SPIRITS,   WINES,   AND   MALT   LIQUORS   IN    THE   UNITED    STATES. 

Distilled  spirits 

(proof  gallons).  Wine  (gallons).  Malt  liquors  (gallons). 

Per  cap.  Per  cap.  Per  cap. 

1905 120,869,649  (1.45)        35,059,717  (0.42)        1,538,526,610  (18.50) 

1906 127,851,583  (1.52)        46,485,223  (0.55)        1,700,421,221  (20.19) 

1907 140,084,436  (1.63)        57,738,848  (0.67)        1,823,313,525  (21.24) 

1908 125,379,314  (1.44)        52,121,646  (0.60)        1,828,732,448  (20.98) 

1009 121,130,036(1.37)        61,779,549(0.70)         1,752,634,426(19.79) 

(Statistical  Abstract  of  United  States.) 

IV.   6.   CONSUMPTION   OF   SPIRITS,    WINES,    AND   BEER   DURING    1901-1908    PER   CAPITA   IN 
DIFFERENT  COUNTRIES    (IN   IMPERIAL  GALLONS). 

Spirits.  Wine.  Beer. 

Australia    0.89  1.29  11.88 

Belgium     1.06  1.02  47.75 

Canada    0.86  0.09  5.01 

Denmark    2.54                 20.58 

France    1.35  30.67  7.92 

Germany    1.55  1.45  26.25 

Holland   1.50  0.37  6.50 

Italy     0.25  25.04  0.14 

Norway     0.62               3.45 

Russia    0.94               0.98 

Sweden     1.46               12.60 

Switzerland    0.97  13.65  13.88 

United  Kingdom   1.00  0.32  29.45 

United  States    1.45  0.52  18.50 

(Webb,  Dictionary  of  Statistics,  1910.) 


278 


MILK  INDUSTRIES. 


CHAPTER    VII. 

MILK   INDUSTRIES. 

I.  Raw  Materials. 

MILK  is  the  fluid  secreted  by  the  females  of  the  mammalia  for  the 
nourishment  of  their  young,  and  is  therefore  a  food  specially  adapted  for 
the  needs  of  the  animal  organism  at  this  stage,  furnishing  all  the  nutrients 
required  and  furnishing  them  in  the  proper  proportion.  As  will  be  seen 
from  its  analysis,  it  occupies  an  intermediate  position  between  the  cereal 
and  the  strictly  animal  foods,  approximating,  of  course,  more  nearly  the 
latter,  but  showing  in  one  important  constituent,  milk-sugar,  its  rela- 
tionship to  the  former. 

Milk  is  a  secretion  of  the  mammary  glands,  in  which  it  is  produced 
proximately  by  certain  processes  of  diffusion  from  the  blood  and  imme- 
diately by  the  breaking  down  of  the  gland-cells  themselves,  so  that  milk 
is  described  as  cell-material  liquefied.  The  milk  of  all  mammalia  is 
essentially  the  same  in  its  constituents,  although  these  vary  somewhat  iu 
their  relative  proportions. 

The  essential  constituents  of  milk  are  water,  fat,  casein,  albumen, 
milk-sugar,  and  salts.  The  relative  proportion  of  these  constituents  in 
the  milk  of  different  animals  may  be  seen  from  the  following  table  of 
analyses  from  Wynter  Blyth :  * 


Fat. 

Casein. 

Albu- 
men, 

Milk- 
sugar. 

Ash. 

Total 
solids. 

Water. 

Human  milk  

2.90 

2.40 

0.57 

5.87 

0.16 

12.00 

88.00 

Cow's  milk     

3.50 

3.98 

0.77 

4.00 

0.17 

13.13 

86.87 

Camel's  milk  

2.90 

f—~ 
3. 

1  —  , 
84 

5.66 

0.66 

13.06 

86.94 

Goat's  milk        

420 

v— 

300 

,  —  •* 
062 

400 

056 

12.46 

87  54 

Ass's  milk  

1  02 

1.09 

0.70 

650 

0.42 

8-83 

91.17 

Mare's  milk  

2  50 

2.19 

0.42 

5  50 

0.50 

11.20 

88.80 

Sheep's  milk  

530 

6.10 

1  00 

420 

1.00 

17.73 

82.27 

In  taking  up  milk  as  a  raw  material  for  industrial  utilization,  we 
shall  refer  to  cow's  milk  exclusively  unless  otherwise  specified. 

The  fat  exists  in  the  milk  in  the  form  of  minute  globules  suspended 
in  a  thin  liquid,  forming  for  the  time  a  perfect  emulsion  with  the  aqueous 
solution  of  the  -other  constituents.  The  fat  is  essentially  an  intimate 


*  Foods,  Composition  and  Analysis,  1882,  pp.  214,  etc. 


RAW  MATERIALS.  279 

mixture  of  the  glycerides  of  the  fatty  acids,  palmitic,  stearic,  and  oleic, 
not  soluble  in  water,  and  of  the  glycerides  of  certain  soluble  volatile 
acids,  such  as  butyric,  caproic,  caprylic,  and  capric. 

The  casein  of  milk  exists  in  the  fresh  milk  as  a  diffused  colloidal 
compound  of  albumen  and  calcium  phosphate,  which  by  the  action  of 
rennet  (a  ferment  from  the  calf's  stomach)  is  converted  into  the  in- 
soluble one  known  as  casein.  The  casein  precipitated  by  rennet  con- 
tains five  to  eight  per  cent,  of  ash,  consisting  almost  entirely  of  calcium 
phosphate.  If,  however,  this  calcium  phosphate  compound  of  albumen 
is  decomposed  by  mineral  acids  or  acetic  acid,  the  casein  precipitated 
contains  only  traces  of  ash.  Lactic  acid  gives  the  same  result,  so  that 
the  casein  coagulated  by  the  souring  of  the  milk  shows  less  ash  than 
that  precipitated  by  rennet  from  sweet  milk.  On  the  other  hand,  carbon 
dioxide  will  act  like  rennet.  The  soluble  compound  existing  in  the  fresh 
milk  is  considered  to  be  that  of  the  tricalcium  phosphate  with-  albumen, 
while  the  insoluble  one  precipitated  by  rennet  is  the  acid  calcium  phos- 
phate with  albumen.  Pure  casein  is  a  perfectly  white  brittle  crumbling 
substance,  insoluble  in  water,  but  soluble  in  very  dilute  acids  or  very 
dilute  alkalies.  In  the  action  of  rennet  and  acids  upon  casein  a  portion 
is  apparently  altered  into  what  are  called  peptones  (lacto-protein  or 
lacto-peptone)  and  remains  dissolved  in  the  whey  of  the  milk.  The 
albumen  (or  soluble  nitrogenous  matter)  of  milk  seems  to  be  analogous 
to  the  albumen  of  blood.  It  may  be  obtained  by  precipitation  with  basic 
acetate  of  lead  or  by  dialysis  as  a  yellowish  flaky  mass.  The  proportion 
of  albumen  in  milk  is  always,  according  to  Wynter  Blyth,  about  one- 
fifth  of  the  casein. 

Two  additional  nitrogenous  compounds  have  been  found  by  Blyth  to 
exist  in  small  amounts  in  milk,  to  which  the  names  galactine  and  lacto- 
chrome  have  been  given. 

Milk-sugar,  which  is  an  important  and  characteristic  constituent  of 
the  milk,  is  obtained  from  the  serum,  or  ' '  whey. ' '  After  the  separation 
of  the  curd  has  been  effected  by  the  addition  of  rennet  the  whey  is 
evaporated  on  the  water-bath,  and  yields  the  milk-sugar  in  hard  crys- 
tals. These  when  purified  by  animal  charcoal  and  recrystallized  show 
the  composition  C^H^O^  -f-  H2O.  It  is  easily  distinguished  from 
other  sugars  of  the  same  formula.  It  is  converted  by  boiling  with 
dilute  acids  into  dextrose  and  galactose,  which  latter  has  one-fifth  less 
copper-reducing  power  than  dextrose.  It  undergoes  the  lactic  fermen- 
tation readily  but  the  alcoholic  with  some  difficulty. 

The  ash  of  milk  consists  of  calcium  citrate  and  the  phosphates  and 
chlorides  of  potassium,  sodium,  calcium,  and  magnesium,  the  salts  that 
are  specially  needed  for  the  growth  of  the  bone-material  in  the  young 
nourished  by  the  milk. 

Cow's  milk  is  a  white  or  yellowish- white  liquid  nearly  opaque,  ex- 
cept in  very  thin  layers,  when  it  has  a  bluish  opalescent  appearance,  and 
a  specific  gravity  of  from  1.029  to  1.035.  It  has  a  mild  sweetish  taste 
and  a  slight  but  characteristic  odor,  stronger  when  still  warm  from  the 


280 


MILK  INDUSTRIES. 


cow.  Upon  allowing  milk  to  remain  at  rest  for  some  time  it  undergoes 
two  changes :  First,  a  yellowish- white  layer  forms  on  the  surface  known 
as  ' '  cream, ' '  due  to  the  rising  of  the  specifically  lighter  fat-globules  from 
the  body  of  the  liquid  where  they  were  held  back  in  emulsion  with  the 
aqueous  liquid;  and,  second,  the  aqueous  liquid  after  a  time  undergoes 
further  separation  into  a  thick  coagulum  or  "curd  "  of  casein  and  a 
thinner  liquid  or  "whey,"  holding  the  sugar  of  milk,  any  lactic  acid 
formed  from  it,  and  the  salts  in  solution.  Both  of  the  changes  are  of 
the  greatest  importance,  as  upon  them  are  based  the  great  milk  indus- 
tries, butter-making  and  cheese-making  respectively. 

The  rising  of  the  cream  is  largely  dependent  ordinarily  upon  two 
conditions:  First,  the  temperature, — a  low  temperature  being  favorable 
to  the  separation;  and,  second,  complete  freedom  from  agitation.  These 
conditions  are  not,  however,  indispensable,  as  will  be  seen  later  (p.  282) 
in  speaking  of  the  use  of  centrifugals  for  the  separation  of  cream. 

The  rising  of  the  cream  is  generally  allowed  to  be  an  entirely  spon- 
taneous change  on  the  part  of  the  milk  and  the  first  one  which  it  under- 
goes, but  in  some  creameries  a  little  sour  milk  (containing  lactic  acid) 
is  added  to  the  fresh  milk,  when  first  put  in  the  cream-rising  pans,  so 
that  the  curdling  of  the  casein  may  facilitate  the  escape  of  the  fat- 
globules  and  the  rising  of  the  cream.  In  such  a  case  what  remains  on 
removal  of  the  cream  is  not  ordinary  skimmed  milk,  but  a  sour  curdled 
milk.  The  second  change  mentioned,  that  of  curdling,  is  really  preceded 
by  a  change  of  some  of  the  milk-sugar  into  lactic  acid  (due  to  lactic 
fermentation,  which  sets  in  very  quickly  in  hot  weather  or  if  the  milk 
has  not  been  kept  in  clean  vessels).  This  souring  of  the  milk  may  be 
retarded  by  the  addition  of  a  little  carbonate  of  soda  or  boric  acid.  The 
lactic  acid  as  soon  as  liberated  decomposes  the  soluble  casein  compound, 
before  referred  to  (see  p.  279),  and  the  casein  is  thrown  out  or  coagulated 
as  ' '  curd. ' '  The  separation  of  the  curd  is  aided  by  heat.  The  liquor  in 
which  this  coagulated  casein  floats,  the  serum  of  milk,  or  ".whey,"  con- 
tains about  one-fourth  of  the  nitrogenous  matter  of  the  milk,  all  of  its 
sugar,  and  most  of  its  mineral  matter.  The  whey  is  "sour  whey  "  in 
case  lactic  acid  has  formed  as  the  antecedent  of  the  coagulation,  or  "sweet 
whey  "  in  case  the  casein  is  thrown  out  by  the  action  of  rennet  without 
the  formation  of  lactic  acid. 

The  composition  of  the  several  parts  into  which  the  milk  is  divided 
by  these  changes  is  thus  given  by  Fleischmann: 


Water. 

Fat. 

Casein. 

Albumen. 

Milk-sugar. 

Ash. 

Whole  milk  

87.60 

3.98 

3.02 

0.40 

4.30 

0.70 

Cream  

77  30 

15.45 

3.20 

020 

3.15 

0.70 

Skim-milk  ........ 

9034 

1  00 

2  87 

*     0  45 

4.63 

0.71 

Butter  

14  89 

8202 

1  97 

028 

028 

056 

Buttermilk     

91.00 

0.80 

3.50 

0.20 

3.80 

0.70 

Curd    

59.30 

6  43 

2422 

3.53 

5.01 

1.51 

"Whey  

9400 

035 

040 

0.40 

4.55 

0.60 

PROCESSES  OF  MANUFACTURE.  281 

And  the  relative  yield  of  these  several  constituents  from  one  hundred 
parts  of  milk  is  thus  given  by  the  same  author : . 

100  parts  of  sweet  milk  will  yield  (by  natural  cream-raising  or  by  centrifugal 
cream-separating) 

• ' T 1 

20  parts  of  cream,  which  79.70  parts  of  skimmed  milk,  which  0.30  parts 

(churned  into  butter)  (coagulated  by  rennet  or  acids)  loss, 

will  yield  will  yield 


3.56  parts  16.30  parts  7.93  parts  71.45  parts 

butter.  buttermilk.  curd.  whey. 

0.14  loss.  0.32  loss.        0.30  loss 

n.  Processes  of  Manufacture. 

1.  MANUFACTURE  OF  CONDENSED  AND  PRESERVED  MILK. — Condensed 
milk  is  milk  from  which  a  large  portion  of  the  water  originally  present 
has  been  driven  off,  increasing,  of  course,  in  a  proportionate  degree  the 
percentage  of  the  other  constituents.     This  condensed  product  may  or 
may  not  have  cane-sugar  added  to  it  as  a  preservative.    That  to  be  pre- 
served with  cane-sugar  is  made  much  more  concentrated,  and  is  that 
which  is  manufactured  for  export  and  preservation  in  sealed  tin  cans. 
In  its  preparation,  the  milk  is  first  heated  to  65.6°  to  80°  C.  (150°  to 
175°  F.)  by  placing  the  cans  containing  the  milk  in  hot  water,  and  is 

.then  strained  and  conveyed  to  the  evaporating  vessels,  which  are  usually 
vacuum-pans.  Refined  sugar  is  added  during  the  boiling  to  the  amount 
of  one  to  one  and  a  half  pounds  for  every  quart  of  the  condensed  milk 
produced.  The  product  is  drawn  off  into  cans,  cooled  to  about  70°  F., 
and  then  weighed  into  tins,  which  are  at  once  soldered  down. 

Condensed  milk  free  from  cane-sugar  is  only  concentrated  to  about 
one-half  the  degree  attained  in  the  other  product,  and  is  then  cooled  and 
filled  into  stone  or  glass  flasks  provided  with  ordinary  air-tight  stoppers. 
It  will  remain  fresh  for  from  one  to  two  weeks,  and  requires  only  to  be 
diluted  with  its  own  bulk  of  water  in  order  to  yield  the  counterpart  of 
the  original  milk. 

Preserved  milk  is  either  prepared  by  Appert's  process,  which  con- 
sists in  boiling  the  milk  to  destroy  ferments  and  keeping  it  then  in  her- 
metically-sealed vessels,  or  by  Scherff's  improved  process,  whereby  the 
milk  is  filled  into  glass  bottles  which  are  stopped  with  corks  previously 
steamed  and  then  fastened  in  by  clamps,  and  then  heated  in  closed 
boilers  under  a  pressure  of  from  two  to  four  atmospheres  to  about  120°  C. 
The  bottles  are  then  taken  out  of  the  pressure-vessel  and  cooled  down, 
with  the  corks  covered  with  flannel  soaked  in  paraffin,  so  that  as  they 
cool  the  air  entering  through  the  pores  of  the  corks  shall  be  filtered. 
"When  cooled  down,  the  cork,  which  has  been  drawn  into  the  neck  of  the 
bottle  considerably,  is  covered  with  a  layer  of  paraffin.  This  kind  of 
preserved  milk  is  used  largely  in  Germany  for  invalids  and  children. 

2.  OF  BUTTER. — The  first  operation  in  this  connection  is  the  separa- 
tion as  completely  as  possible  of  the  cream  from  the  rest  of  the  milk. 
This  is  generally  a  spontaneous  process,  it  is  true,  but  its  completeness 
is  dependent  largely  upon  the  conditions  before  referred  to.    There  are 


282 


MILK  INDUSTRIES. 


various  ways  in  which,  the  raising  of  the  cream  is  allowed  to  take  place. 
We  may  mention  the  Holstein  process,  in  which  the  fresh  milk  is  at  once 
set  to  raise  cream  in  wide  shallow  pans  at  a  temperature  of  12°  to  15°  C. 
(53.6°  to  59°  P.),  the  Dutch  process,  in  which  it  is  first  rapidly  cooled 
down  in  large  vessels  immersed  in  cold  water  to  about  15°  C.  (59°  P.) 
and  then  transferred  to  the  shallow  pans  for  the  raising  of  the  cream, 
and  the  Schwartz  process,  largely  used  in  Northern  Europe,  which 
differs  from  the  Dutch  process  chiefly  in  using  much  deeper  pans  at  a 

lower  temperature,  4.4°  to  10° 

FIG.  71.  C.     (40°    to    50°    P.).      Very 

similar  to  this  last  mentioned 
are  the  Hardin  and  the  Cooley 
methods,  which  also  use  deep 
cream-raising  pans.  In  the 
former  of  these,  ice  and  not 
ice-water  is  used  to  effect  the 
cooling,  the  pans  being  exposed 
to  the  influence  of  air  cooled 
by  ice,  the  claim  being  made 
that  the  cream  is  obtained  in 
more  solid  condition.  In  the 

FIG.  72. 


Cooley  method,  used  largely  in  this  country,  the  water  not  only  sur- 
rounds the  can  outside  as  high  as  the  milk  inside,  but  is  made  to  rise  an 
inch  or  two  above  the  lid,  so  that  the  can  is  completely  submerged  and 
all  contamination  from  external  sources  prevented. 

The  processes  which  use  shallow  pans  give  a  larger  yield  of  cream  but 
take  a  longer  time  (thirty-six  to  forty-eight  hours  as  against  eighteen  to 
twenty-four  for  those  using  deep  pans).  Within  twenty  years  past  the 
principle  of  the  centrifugal  has  been  applied  to  the  separation  of  the 
cream  from  the  milk,  and  this  has  proven  itself  so  successful  that  in 
most  large  creameries  it  is  now  utilized.  The  milk  is  placed  in  a  hori- 
zontal rotating  vessel  driven  at  a  high  rate  of  speed,  which  causes  the 
heavier  milk  fluid  to  gravitate  towards  the  circumference  of  the  vessel, 


PROCESSES  OF  MANUFACTURE. 


283 


whilst  the  cream  remains  nearer  the  centre  and  rises  towards  the  upper 
part  of  the  rotating  bowl,  whence  it  is  removed  by  a  conveniently-placed 
aperture  on  the  side  of  the  vessel.  An  exit  is  also  provided  for  the 
gradual  removal  of  the  skimmed  milk,  thus  making  room  for  fresh  milk 
to  be  added  to  the  apparatus  and  allowing  the  process  to  be  carried  on 
continuously.  Figs.  71  and  72  show  the  Laval  cream  separator  in  gen- 
eral view  and  in  section.  The  fresh  milk  is  admitted  through  a  funnel, 
the  tube  of  which  is  prolonged  so  as  to  deliver  the  milk  near  the  bottom 
of  the  revolving  drum.  The  skim-milk  flows  out  through  an  opening,  t, 
and  the  cream  through  a  higher  opening,  the  relative  position  of  which 
can  be  changed  by  an  adjustable  screw  above.  The  cream  obtained  by 
these  centrifugal  separators  seems  to  be  freer  from  mechanically- 
enclosed  casein  than  that  gotten  in  any  of  the  old  separation  processes, 
as  is  seen  in  the  appended  cream  analyses  by  Bell,*  where  samples  2  and 
6  were  separated  by  the  centrifugal  separator: 


Water. 

Fat. 

Milk- 
sugar. 

Casein. 

Ash. 

I. 

Raw  cream     

54.02 

39.40 

1.85 

3.76 

0.57 

2 

Raw  cream     

60.66 

33.60 

2.43 

2.90 

0.41 

8, 

67.93 

24.44 

2.96 

4.04 

0.63 

4 

Raw  cream     

5807 

35  67 

220 

3.55 

0.51 

5 

Raw  cream     

63.07 

30.74 

2.61 

3.04 

0.54 

6 

Thick  cream  

37.62 

58.77 

1.46 

1.83 

0.32 

7 

Devonshire  clotted  cream    

33  76 

59.79 

1.01 

4.97 

0.47 

! 

The  composition  of  the  skimmed  milk  of  course  varies  according  to 
the  extent  to  which  the  cream  has  been  removed.  The  following  analyses 
by  Voelcker  represent  its  average  composition  as  obtained  in  the  ordinary 
way  and  as  obtained  by  the  Laval  separator : 


Water. 

Butter- 
fat. 

Casein. 

Milk- 
sugar. 

Ash. 

Ordinary  skimmed  milk     

89.25 

1.12 

3.69 

5.17 

0  78 

Skimmed  milk  by  Laval  separator  

90.82 

0.31 

3.31 

4.77 

0.79 

The  coalescence  of  the  fat-globules  separated  in  the  cream  layer  is 
now  to  be  effected  to  form  the  compact  butter.  This  is  almost  univer- 
sally accomplished  by  mechanical  agitation  in  the  process  called  churn- 
ing. The  churns  may  be  of  very  diverse  construction,  either  for  hand 
or  power.  The  cream  may  be  taken  as  ' '  sweet  cream  ' '  freshly  separated 
in  the  centrifugal  or  raised  from  deep  pans  where  the  skim-milk  is  still 
sweet,  or  it  may  be  "sour  cream,"  which  has  stood  longer  and  has 
separated  slowly  in  shallow  pans.  The  sour  cream  is  more  easily  churned, 
but  the  butter  will  contain  more  casein,  while  sweet  cream  yields  a  butter 
with  pleasanter  taste  and  better  keeping  qualities  because  containing  less 

*  Analysis  and  Adulteration  of  Food,  p.  35. 


284 


MILK  INDUSTRIES. 


casein.  The  temperature  most  favorable  for  churning  is  about  15.5°  C. 
(60°  F.).  Sometimes  cream  is  heated  to  a  much  higher  temperature 
first,  and  then  cooled  down  to  60°  F.  before  being  churned.  Butter  thus 
made  keeps  well. 

Butter  has  almost  invariably  some  salt  added  to  it  even  when  for 
immediate  consumption;  the  quantity  in  this  case  need  not  be  large 
(five-tenths  to  two  per  cent.),  but  when  it  is  to  be  packed  for  preser- 
vation or  for  export  considerably  more  is  added,  so  that  it  is  known  as 
"salt  butter."  Export  butter  has  also  a  small  addition  of  sugar,  and 
sometimes  saltpetre,  added,  as  well  as  salt,  to  preserve  it.  Genuine 

FIG.  73. 


butter  will  always  have  a  yellowish  color,  which,  however,  becomes  deeper 
in  summer  when  the  cows  have  an  abundance  of  fresh  pasture.  Most 
butter  manufacturers  now  add  a  little  vegetable  coloring  matter  like 
annotto,  «arrot-color,  or  saffron,  to  give  the  butter  this  desired  yellow 
tint  in  winter,  when  the  butter  would  otherwise  be  very  much  lighter 
in  color.  All  butter  will  in  time  become  rancid  and  take  a  strong  dis- 
agreeable odor.  This  is  due  to  the  gradual  spontaneous  decomposition 
of  the  butyric  ether  under  the  influence  of  air  and  light  whereby  free 
butyric  acid  is  liberated. 

The  composition  of  butter  will  be  more  fully  spoken  of  later  on  in 
discussing  the  products  of  these  industries. 

3.  OF  ARTIFICIAL  BUTTER  (Butterine,  Oleomargarine}. — The  manu- 
facture of  substitutes  for  normal  dairy  butter  began  with  the  experiments 
of  the  Frenchman  Mege-Mouries  in  1870.  He  found  that  carefully- 


PROCESSES  OF  MANUFACTURE. 


285 


washed  beef-suet  furnished  a  basis  for  the  manufacture  of  an  excellent 
substitute  for  natural  butter.  The  thoroughly- washed  and  finely-chopped 
suet  was  rendered  in  a  steam-heated  tank,  taking  for  one  thousand  parts 
of  fat,  three  hundred  parts  of  water,  one  part  of  carbonate  of  potash, 
and  two  stomachs  of  pigs  or  sheep.  The  temperature  of  the  mixture  was 
raised  to  45°  C.  After  two  hours,  under  the  influence  of  the  pepsin  in 
the  stomachs,  the  membranes  are  dissolved  and  the  fat  melted  and  risen 
to  the  top  of  the  mixture.  After  adding  a  little  salt,  the  melted  fat  is 
drawn  off,  stood  to  cool  so  as  to  allow  the  stearin  and  palmitin  to  crys- 
tallize out,  and  then  pressed  in  bags  in  a  hydraulic  press.  Forty  to  fifty 
per  cent. .of  solid  stearin  remains,  while  fifty  to  sixty  per  cent,  of  fluid 

FIG.  74. 


oleopalmitin  (so-called  "oleomargarine  ")  is  pressed  out.  Mege  then 
mixed  the  ' '  oleo  oil  ' '  with  ten  per  cent,  of  its  weight  of  milk  and  a  little 
butter-color  and  churned  it.  The  fat-cutting  process  of  Mege-Mouries 
is  shown  in  Fig.  73  and  the  churning  of  the  "oleo  oil  "  in  Fig.  74.  The 
product  was  then  worked,  salted,  and  constituted  the  "oleomargarine," 
or  butter  substitute.  Various  improvements  have  been  made  in  the 
process  of  Mege,  and  it  has  been  found  that  leaf-lard  can  be  worked  in 
the  same  way  as  beef-suet,  and  will  yield  an  oleopalmitin  suitable  for 
churning  up  into  a  butter  substitute. 

The  processes  now  followed  are  given  substantially  as  described  by 
Mr.  Phil.  D.  Armour  in  his  testimony  before  a  committee  of  Congress  :* 
"The  fat  is  taken  from  the  cattle  in  the  process  of  slaughtering,  and 
after  thorough  washing  is  placed  in  clean  water  and  surrounded  with 

*  Department  of  Agriculture,  Bulletin  No.  13,  Part  i.  p.  16. 


286  MILK  INDUSTRIES. 

ice,  where  it  is  allowed  to  remain  until  all  animal  heat  has  been  removed. 
It  is  then  cut  into  small  pieces  by  machinery  and  cooked  at  a  tempera- 
aure  of  about  150°  F.  (65.6°  C.)  until  the  fat  in  liquid  form  has  sepa- 
rated from  the  fibrin  or  tissue,  then  settled  until  it  is  perfectly  clear. 
Then  it  is  drawn  into  graining-vats  and  allowed  to  stand  for  a  day,  when 
it  is  ready  for  the  presses.  The  pressing  extracts  the  stearin,  leaving  a 
product  commercially  known  as  'oleo  oil,'  which  when  churned  with 
cream  or  milk,  or  both,  and  writh  usually  a  proportion  of  creamery  butter, 
the  whole  being  properly  salted,  gives  the  new  food  product,  oleomar- 
garine. In  making  butterine  we  use  'neutral  lard,'  which  is  made  from 
selected  leaf-lard  in  a  very  similar  manner  to  oleo  oil,  excepting  that 
no  stearin  is  extracted.  This  neutral  lard  is  cured  in  salt  brine  for 
forty-eight  to  seventy  hours  at  an  ice-water  temperature.  It  is  then 
taken  and  with  the  desired  proportion  of  oleo  oil  and  fine  butter  is 
churned  with  cream  and  milk,  producing  an  article  which  when  properly 
salted  and  packed  is  ready  for  the  market. 

"In  both  cases  coloring  matter  is  used,  which  is  the  same  as  that 
used  by  dairymen  to  color  their  butter.  At  certain  seasons  of  the  year — 
viz.,  in  cold  weather — a  small  quantity  of  sesame  oil  or  salad  oil  made 
from  cotton-seed  oil  is  used  to  soften  the  texture  of  the  product," 

It  will  be  seen  that  in  this  process  a  higher  temperature  is  used  in 
rendering  the  fat  than  wras  used  originally  by  Mege.  He  obtained  about 
fifty  per  cent,  of  oleo  oil.  The  manufacturers  now  obtain  sixty-two  per 
cent,  or  more.  The  oleo  oil  from  beef -suet  and  the  neutral  lard  from 
leaf-lard  are  frequently  mixed,  the  proportions  varying  according  to  the 
destination  of  the  product;  a  warm  climate  calling  for  more  "oleo,"  a 
cold  one  for  more  "neutral."  In  ordinary  practice  about  forty-eight 
gallons  of  milk  are  used  for  churning  with  the  oil  per  two  thousand 
pounds  of  product.  Plain  oleomargarine  is  the  cheapest  product  made. 
By  adding  to  the  material  in  the  agitator  or  churn  more  or  less  pure 
butter  what  is  known  as  butterine  is  produced,  two  grades  of  which  are 
commonly  sold, — viz.,  "creamery  butterine,"  containing  more,  and 
"dairy  butterine,"  containing  less,  butter. 

Large  quantities  of  oleo  oil  are  now  manufactured  and  exported  as 
such  from  the  United  States  to  Europe,  notably  to  Holland,  where  it  is 
made  up  into  oleomargarine  butter.  There  are  said  to  be  seventy  manu- 
factories of  this  kind  in  Holland  which  work  up  oleo  oil  from  all  parts 
of  the  world. 

4.  CHEESE-MAKING. — The  manufacture  of  cheese  depends  upon  the 
property  possessed  by  casein  of  being  curdled  by  acids  or  ferments.  In 
the  case  of  sour  milk,  the  milk-sugar  has  developed  by  the  lactic  fermen- 
tation some  lactic  acid,  and  this,  as  before  stated,  promptly  throws  out 
the  casein  in  the  insoluble  form.  In  the  case  of  sweet  milk  we  usually 
accomplish  the  curdling  of  the  casein  not  by  the  use  of  an  acid,  but 
with  a  ferment  contained  in  the  preparation  called  rennet.  This  is  pre- 
pared from  the  fourth  stomach  of  the  calf  by  first  cleansing  the  stomach, 
cutting  and  drying  it,  and  then  leaving  some  brine  in  contact  with  its 
lining  membrane  for  a  few  days.  The  salt  liquid  will  thus  acquire  very 


PROCESSES  OF  MANUFACTURE.  287 

active  properties,  so  that  a  small  quantity  will  curdle  a  large  quantity 
of  milk.  We  would  have  then,  according  as  one  or  the  other  method  is 
followed,  a  sour-milk  cheese  or  a  sweet-milk  cheese.  The  former  have  a 
very  minor  value  commercially,  being  made  mainly  for  immediate 
domestic  consumption.  The  latter  class  include  all  the  more  valuable 
commercial  varieties.  Of  these  we  may  distinguish  fat,  half-fat  (or 
medium),  and  lean  cheeses,  or  as  they  are  also  designated  to  indicate 
their  origin,  cream  cheeses,  whole  milk  cheeses,  and  skim-milk  cheeses. 
As  these  last  names  indicate,  the  material  may  differ.  "We  may  have, 
moreover,  all  gradations  or  mixtures  of  cream,  whole  milk,  and  skim- 
milk  used  for  the  various  grades  manufactured. 

In  cheese-making  from  sweet  milk,  the  milk,  whether  whole,  mixed 
with  cream,  or  skimmed,  is  heated  to  about  30°  C.  (86°  F.)  and  the 
rennet  added.  It  curdles  usually  in  from  thirty  to  forty  minutes.  After 
the  curd  has  formed  and  been  cut,  or  "broken  down,"  the  heat  is  raised 
to  98°  F.  (36°  C.)  to  insure  the  souring  of  the  whey  and  its  more  com- 
plete separation  from  the  curd.  Or  the  curd  produced  at  not  over  86°  F. 
(30°  C.)  is  after  being  cut  collected  in  a  heap,  covered  with  a  cloth  to 
preserve  the  heat,  and  allowed  to  stand  an  hour  to  develop  the  acidity 
which  serves  to  harden  the  curd  and  promote  its  separation  from  the 
whey.  The  curd  is  now  cut  up,  worked  to  free  it  from  the  whey,  salted 
and  pressed.  After  it  has  acquired  sufficient  coherence  (which  requires 
from  twelve  to  fourteen  hours)  it  is  taken  from  the  press  and  placed 
in  the  curing-room  to  "ripen."  This  ripening  process  is  essentially  a 
fermentative  one,  and  during  its  progress  the  curd  loses  its  insipidity 
and  acquires  the  characteristic  taste  and  flavor  of  cheese. 

In  this  process  of  ripening,  the  milk-sugar  remaining  in  the  cheese 
becomes  transformed  partly  into  lactic  acid  and  partly  into  alcohol  and 
carbon  dioxide.  In  some  varieties  the  carbon  dioxide  swells  up  ("huffs  ") 
the  cheese-mass  and  gives  it  the  porous  character  so  noticeable  in  the 
ripened  cheese. 

Fresh  cheese  has  an  acid  reaction,  but  this  diminshes  more  and  more 
in  the  ripening,  as  the  casein  is  gradually  altered,  soluble  albuminoids, 
peptone-like  bodies,  and  organic  bases  like  leucine,  tyrosine,  and  amines 
being  formed. 

Some  cheeses,  especially  the  cream  cheeses,  are  not  pressed,  but  come 
on  the  market  as  soft  cheeses.  In  these  the  curdling  by  rennet  has  also 
been  effected  at  a  lower  temperature  than  in  the  case  of  the  hard  cheeses. 

Cheese  has  also  been  manufactured  extensively  in  this  country  from 
skimmed  milk  to  which  oleomargarine  or  "oleo  oil  "  has  been  added  so  as 
to  give  the  finished  product  the  character  of  a  whole-milk  cheese.  This 
product  is  now  quite  supplanted,  however,  by  the  "lard  cheese,"  which, 
according  to  Caldwell,*  was  made  in  1882  at  over  twenty  factories  in 
the  State  of  New  York.  In  this  process  an  emulsion  of  lard  is  made  by 
bringing  together  in  a  "disintegrator  "  lard  and  skimmed  milk  both 
previously  heated  to  140°  F.  in  steam-jacketed  tanks;  the  "disintegrator  " 

*  Second  Annual  Report  New  York  State  Board  of  Health,  p.  529. 


288 


MILK  INDUSTRIES. 


consists  of  a  cylinder  revolving  within  a  cylindrical  shell :  the  surface  of 
the  cylinder  is  covered  with  fine  serrated  projections,  each  one  of  which 
is  a  tooth  with  a  sharp  point;  as  this  cylinder  revolves  rapidly  within 
its  shell  the  mixture  of  melted  lard  and  hot  skimmed  milk  is  forced  up 
into  the  narrow  interspace ;  and  the  lard  becomes  very  finely  divided  and 
most  intimately  mixed,  or  ' '  emulsionized, ' '  with  the  milk.  This  emulsion 
consists  of  from  two  to  three  parts  of  milk  to  one  of  lard.  In  making  the 
cheese,  a  quantity  of  this  emulsion,  containing  about  eighty  pounds  of 
lard,  is  added  to  six  thousand  pounds  of  skimmed  milk  and  about  six 
hundred  pounds  of  butter-milk  in  the  cheese-vat,  and  the  lard  that  does 
not  remain  incorporated  with  the  milk  or  curd,  usually  about  ten  pounds, 
is  carefully  skimmed  off.  These  quantities  of  the  materials  yield  from 
five  hundred  to  six  hundred  pounds. of  cheese  containing  about  seventy 
pounds  of  lard,  or  about  fourteen  per  cent.  About  one-half  of  the  fat 
removed  as  cream  in  the  skimming  of  the  milk  is  thus  replaced  by  lard. 
It  is  claimed  that  no  alkali  or  antiseptic  is  used,  and  that  only  the  best 
kettle-rendered  lard  can  be  employed,  because  of  the  injurious  effect  of 
any  inferior  article  on  the  quality  of  the  cheese,  and  that  before  even 
this  lard  is  used  it  is  deodorized  by  blowing  steam  under  eighty  pounds 
pressure  through  it  for  an  hour.  According  to  many  witnesses  the  imi- 
tation is  excellent,  for  experts  have  been  unable  to  pick  out  lard  cheeses 
from  a  lot  of  these  and  full-cream  cheeses  of  good  quality  together. 

m.  Products. 

1.  CONDENSED  AND  PRESERVED  MILK. — The  distinction  between  con- 
densed milk  prepared  with  the  addition  of  cane-sugar  and  that  prepared 
without  sugar  has  already  been  referred  to  in  speaking  of  the  manu- 
facture of  this  class  of  products.  The  first  of  these  classes  forms  a  white 
or  yellowish-white  product  of  about  the  consistency  of  honey  and  rang- 
ing in  specific  gravity  from  1.25  to  1.41.  It  should  be  completely  soluble 
in  from  four  to  five  times  its  bulk  of  water  without  separation  of  any 
flocculent  residue,  and  then  possess  the  taste  of  perfectly  fresh  sweetened 
milk. 

The  second  class  of  condensed  milk  preparations,  those  without  addi- 
tion of  cane-sugar,  are  not  boiled  down  to  the  same  degree  and  remain 
perfectly  liquid,  and  are  put  up  therefore  in  glass  bottles  instead  of 
being  sealed  in  cans.  Analyses  of  both  classes  are  given  on  the  authority 
of  Battershall.* 

Condensed  Milk  with  Addition  of  Sugar. 


BRAND. 

Water. 

Fat. 

Cane-  and 
milk-sugar. 

Casein. 

Salts. 

Alderney     

30.05 

10.08 

46.01 

12.04 

1  82 

Anglo-Swiss  (American)  .... 
Anglo-Swiss  (English)     .... 
Anglo-Swiss  (Swiss)  

29.46 
27.80 
25  51 

8.11 
8.24 
8  51 

50.41 
51.07 
53  27 

10.22 
10.80 
10  71 

1.80 
2.09 
200 

Eagle   

27.30 

6.60 

44.47 

10.77 

1.86 

Crown  

29.44 

9.27 

49.26 

10.11 

1.92 

*  Food  Adulteration  and  its  Detection,  p.  53. 


PRODUCTS. 


289 


Condensed  Milk  without  Cane-sugar. 


BRAND. 

Water. 

Fat 

Milk-sugar. 

Casein. 

Salts. 

American     

52.07 

15.06 

16.97 

14.26 

2.80 

New  York  

56.71 

14.13 

13.98 

13.18 

2.00 

Granulated  Milk  Company     .   . 
Ea^le  . 

55.43 
56.01 

13.16 
14.02 

14.84 
14.06 

14.04 
13.90 

2.53 
2.01 

2.  BUTTER  AND  BUTTER  SUBSTITUTES. — Commercial  butter  is  more 
or  less  granular,  and  the  more  perfect  the  granular  condition  the  higher 
is  its  quality  considered.  Special  effort  has  been  made  in  the  case  of 
oleomargarine  or  butterine  to  imitate  this  granulation,  as  the  artificial 
product  does  not  naturally  tend  to  show  such  appearance.  A  good  butter 
when  fresh  has  a  pleasant  fragrant  odor  and  agreeable  taste,  but  the 
flavor,  like  the  color,  varies  with  the  food  of  the  cow,  certain  plants,  like 
garlic,  giving  a  quite  pronounced  flavor  to  both  milk  and  butter.  At 
ordinary  temperatures  butter  is  easily  cut  or  moulded,  and  it  readily 
melts  to  a  transparent,  light-colored  oil.  It  always  contains,  according  to 
the  thoroughness  with  which  it  has  been  kneaded  and  washed,  more  or 
less  casein,  which  is  very  liable  to  undergo  decomposition,  and  hence  the 
necessity  for  the  addition  of  larger  or  smaller  amounts  of  salt,  which 
acts  as  a  preservative.  When  the  butter-fat  is  freed  from  curd  and  water 
by  melting  the  butter  and  drawing  off  the  oily  layer  it  may  be  kept  for 
a  long  time  without  change. 

This  butter-fat  is  made  up,  as  was  stated  in  speaking  of  the  fat  of 
milk,  of  the  glycerides  of  oleic,  palmitic,  and  stearic  acids  (the  so-called 
insoluble  acids)  and  the  glycerides  of  butyric,  caproic,  caprylic,  and 
capric  acids  (the  so-called  soluble  acids).  The  proportion  in  which  they 
exist  in  butter-fat  varies  within  very  slight  limits  only,  so  that  five  to 
six  per  cent,  may  be  called  the  average  percentage  of  the  soluble  acids, 
and  eighty-eight  per  cent,  the  average  percentage  of  the  insoluble  acids 
present  in  butter-fat.  This  gives  a  very  important  means  of  distinguishing 
between  a  natural  butter  and  oleomargarine  or  natural  butter  adulterated 
with  the  imitations.  In  such  butter  the  glycerides  of  the  soluble  acids 
(butyric,  etc.),  are  either  wanting  entirely  or,  if  a  little  cream  was  used 
in  the  churning  with  "oleo  oil,"  present  in  very  much  smaller  amount 
than  the  normal.  This  distinction  will  be  evident  from  the  analyses  of  nor- 
mal butter  and  oleomargine  butters,  given  on  the  authority  of  Dr.  Bell.  * 

Genuine  Butter,  showing  Range  of  Variation  in  Composition  of  the  Fat. 


Water. 

Salt 

Curd. 

Butter- 
fat. 

Specific 
gravity  at 
100°  F. 

Percentage  of 
fixed  acids  in 
fat. 

Percentage  of 
soluble  acids 
as  butyric. 

Melting 
point, 
Fahren- 
heit. 

1. 

7.55 

1.03 

1.15 

90.27 

913.89 

85.56 

7.41 

85°  F. 

2. 

11.71 

3.60 

0.95 

83.74 

911.45 

88.24 

5.41 

90°  F. 

3. 

11.42 

1.29 

1.12 

86.17 

910.47 

88.53 

4.84 

90°  F. 

4. 

1255 

0.89 

0.74 

85.82 

910.20 

89.00 

4.57 

90°  F. 

5. 

14.62 

1.48 

1.88 

82.02 

910.70 

89.00 

4.50 

91°  F. 

Analysis  and  Adulteration  of  Foods,  pp.  68  and  70. 
19 


290  MILK  INDUSTRIES. 

Analyses  of  Oleomargarine  Butter  or  Butterme. 


Specific 

Percentage 

.Percentage 

Melting 

Water. 

Salt. 

Curd. 

Fat. 

gravity  at 
100°  F. 

of  fixed 
acids. 

of  soluble 
acids. 

point.  Fah- 
renheit. 

14.30 

3.81 

0.48 

81.41 

903.84 

94.34 

82°  F. 

11.21 

1.70 

1.73 

85.36 

902.34 

94.83 

0.66 

78°  F. 

12.33 

400 

1.09 

82.58 

903.15 

95.04 

0.47 

79°  F. 

5.32 

1.09 

0.67 

9292 

903  79 

96.29 

0.23 

81°  F. 

13.21 

3.99 

1.07 

81.73 

901.36 

95.60 

0.16 

78°  F. 

The  best  grades  of  artificial  butter  do  not  differ  in  appearance  from 
ordinary  butter.  To  induce  the  proper  granulation  of  the  oleomargarine, 
it  is  chilled  thoroughly  with  fragments  of  ice  immediately  after  it  is 
taken  from  the  churn  and  before  kneading  or  salting  it.  In  color,  con- 
sistence, and  taste  it  may  be  made  to  imitate  the  natural  butter  so  as  to 
deceive  most  persons.  A  distinction,  it  is  said,  however,  can  always  be 
noted  in  the  taste  when  it  is  melted  upon  hot  boiled  potatoes,  to  which  it 
imparts  a  peculiar  taste  recognizable  as  distinct  from  that  of  a  true 
butter, 

3.  CHEESE. — The  general  classification  of  the  cheeses  has  been  given 
in  speaking  of  the  methods  of  manufacture,  and  the  distinctions  between 
the  fat  and  lean  cheeses,  between  cream  cheese,  whole-milk  and  skimmed- 
milk  cheeses  given.  The  terms  hard  and  soft  cheeses  are  applied  accord- 
ing as  the  curd  has  or  has  not  been  pressed  in  the  process  of  manufac- 
turing. Most  of  the  names  which  have  been  attached  to  the  different 
varieties  of  cheese  are  those  of  localities.  We  will  indicate  the  character 
of  a  few  of  these. 

Neufchatel  cheese  is  a  Swiss  cream  cheese. 

Limburger  cheese  is  a  soft  fat  cheese. 

Fromage  de  Brie  is  a  soft  French  cheese  rapidly  ripening  and  devel- 
oping ammoniacal  compounds. 

Camembert  cheese  is  also  a  cream  cheese. 

Roquefort  cheese  is  a  cheese  made  from  the  milk  of  the  ewe. 

Gruyere  cheese  is  a  peculiarly  flavored  Swiss  cheese. 

Cheddar  cheese  is  a  hard  cheese  made  with  whole  milk. 

Single  and  double  Gloucester  are  made,  the  first  from  a  mixture  of 
skimmed  and  entire  milk,  and  the  second  from  the  entire  milk. 

Parmesan  cheese  is  a  very  dry  cheese,  with  a  large  amount  of  casein 
and  only  a  moderate  percentage  of  fat. 

Eidam  cheese  is  a  Dutch  cheese,  also  relatively  dry,  and  covered  with 
red  coloring. 

In  illustration  of  the  chemical  composition  of  these  different  varieties 
of  cheese  we  will  append  three  tables,  the  first  of  analyses  from  miscel- 
laneous sources,  and  the  second  and  third  from  Bell,*  giving  a  fuller 
study  of  the  composition  of  the  cheeses  andr  showing  the  difference 
between  the  fat  normally  belonging  to  the  cheese  and  the  fat  added  in 
the  shape  of  lard  or  "oleo  oil"  in  adulterated  cheeses. 

*  Analysis  and  Adulteration  of  Foods,  pp.  79  and  82. 


PRODUCTS. 


291 


Water. 

Fat 

Casein. 

Non-nitro- 
genous 
and  loss. 

Ash. 

Neufchatel  (Fleischmann)    

34.50 

41.90 

13.00 

700 

360 

Emmenthaler  (Fleischmann)  

36.10 

2950 

28.00 

330 

810 

Limburger  (Fleischmann)  

35.70 

3420 

2420 

300 

290 

Brie  (Wvnter  Blyth)     

51.87 

24.83 

18.30 

500 

Camembert  (Wynter  Blyth)  

51.30 

21  50 

19.00 

350 

4  70 

Parmesan  (Wynter  Blyth)  

27.56 

15.95 

44.08 

669 

572 

100  PARTS  CONTAIN 

Proportion  of  fat  in 
100  parts  of  dry 
cheese. 

Proportion  of  fat 
in  100  parts  of 
casein  and  fat. 

Salt  percentage  in 
cheese. 

PERCENTAGE 
COMPOSITION 
OF  THE  FAT. 

Water. 

«J 

03 

a 

Free  acid 
as  lactic. 

4 

si 
ia 

Insoluble 
acid. 

Stilton      

23.57 
28.63 
31.55 
32.26 
31.85 

35.60 
33.66 
37.11 
35.75 
41.30 

39.13 
38.24 
35.93 
34.38 
34.34 

31.57 
30.69 
30.68 
28.35 
22.78 

32.55 
29.64 
28.83 
27.16 

27.88 

28.16 
30.67 
26.93 
31.10 
28.25 

1.24 

6.27 
1.32 
1.35 

0.45 
0.27 
0.86 
0.31 
0.57 

3.51 
3.49 
3.42 

4.88 
4.58 

4.22 
4.71 
4.42 
4.49 
7.10 

5119 
53.57 
52.49 
50.75 
49.02 

46.26 
48.78 
48.78 
44.12 
38.80 

52.50 
54.12 
53.34 
54.24 
53.08 

50.49 
47.02 
50.84 
45.24 
42.41 

0.67 
0.72 
0.82 
3.04 
2.11 

1.43 

0.81 
1.69 
1.28 
4.45 

4.42 
4.26 
4.81 
4.91 
4.40 

4.55 
4.41 
5.55 
6.68 
5.84 

88.96 
89.06 
88.49 
88.70 
89.18 

8875 
88.97 
87.76 
86.89 
87.58 

American  (red) 
American  (pale) 
Roquefort   .  .  . 
Gorgonzola    .  . 
Cheddar     (medi 
um)   

Gruyere  

Cheshire  

Single  Gloucester 
Dutch  (Eidam)  .  . 

Analyses  of  Oleomargarine  and  Lard  Cheeses. 


100  PARTS  CONTAIN 

Per 
cent,  of 
salt. 

100  PARTS  OF 
FAT  CONTAIN 

Melting  point 
of  fat. 

Water. 

Fat. 

Casein 
and 
free 
acids. 

Ash. 

Insol- 
uble 
acids. 

Soluble 
acids. 

Oleomargarine  cheese  .  . 
Lard  cheese    

30.95 
31.30 

28.80 
24.66 

36.27 
38.87 

3.98 
5.17 

1.14 
1.55 

92.43 
92.88 

2.16 
1.55 

77°  F.  (25°  C.). 
92°  F.  (33.3°  C.). 

4.  MILK-SUGAR. — The  manufacture  of  crystallized  milk-sugar    (lac- 
tose) has  developed  greatly  in  recent  years,  and  a  perfectly  white,  well- 
crystallized  product  is  now  obtained.     For  its  preparation,  the  sweet 
skim-milk  as  it  comes  from  the  cream  separator  is  precipitated  with 
acetic  acid,  filtered,  and  boiled  either  in  open  steam-heated  evaporators 
or  in  vacuum  pans.     This  first  boiling  should  take  several  hours.     The 
whey  during  the  boiling  becomes  more  cloudy,  but  suddenly  clears,  and 
the  remaining  albuminoids  will  separate  in  large  flocks  that  can  readily 
be  filtered.     It  is  to  be  filtered  hot  and  boiled  to  crystallization  in  a 
vacuum  pan.    The  raw  sugar  so  obtained  can  be  refined  and  made  white 
exactly  as  described  under  cane-sugar.    As  the  first  crystallization  is  all 
that  can  be  brought  to  satisfactory  color  and  purity,  the  yield  is  not 
much  over  ten  per  cent,  of  the  total  sugar  contained  in  the  milk. 

5.  KOUMISS. — Koumiss  is  an  alcoholic  drink  made  by  the  fermenta- 
tion of  milk.    As  made  by  the  fermentation  of  mare's  milk  it  has  long 


292 


MILK  INDUSTRIES. 


been  a  favorite  beverage  with,  the  Tartars  and  other  Asiatic  tribes. 
Cow's  milk  has  been  used  chiefly  in  making  it  in  both  Europe  and  Amer- 
ica. Mare's  milk  is  the  more  suitable  for  fermentation  because  of  the 
larger  percentage  of  milk-sugar  which  it  contains. 

The  fermentation  is  started  by  mixing  fresh  milk  with  some  already 
soured.  Both  the  lactic  and  the  alcoholic  fermentations  are  set  up,  with 
the  production  of  lactic  acid,  alcohol,  and  carbonic  acid  gas.  Some  of 
the  albuminoids  are  also  changed  into  peptones.  The  composition  of  the 
koumiss  as  prepared  from  both  mare's  and  cow's  milk  is  shown  in  the 
accompanying  analyses  from  various  sources: 


.S 

o-d 

i-s 

A 

OH 

isg 

o  jj 

el  & 

fifl 

•g 

o 

B 

•2-2 

oj'O 

4 

* 

S 

h-l 

* 

m 

* 

o 

* 

Koumiss  from  mare's  milk  (Fleischmann) 
Koumiss  from  cow's  milk  (Fleischmann) 
Koumiss  from  mare's  milk  (Konig)     .  .   . 

91.53 
88.93 
92.47 

1.25 
3.11 
1.24 

1.01 

079 
0.91 

1.91 
2.03 
1.97 

1.27 
085 
1.26 

1.85 

2.65 
1.84 

0.88 
1.03 
0.95 

0.29 
0.44 

Koumiss  from  mare's  milk  (London,  1884) 

91.87 

0.79 

1.04 

1.91 

1.19 

2.86 

Koumiss  from  cow's  milk  (Wiley)    .... 

89.32 

4.38 

0.47 

2.56 

2.08 

0.76 

0.83 

•  • 

6.  KEPHIR. — This  is  a  Caucasian  product  somewhat  similar  to  kou- 
miss, but  prepared  from  cow's  milk  in  leathern  bottles  by  the  aid  of  a 
peculiar  ferment  known  as  "kephir  grains."  According  to  Kern,  as 
quoted  by  Allen  (Commercial  Organic  Analysis,  2d  ed.,  vol.  iv,  p.  242), 
the  kephir  ferment  is  an  elastic  cauliflower-like  mass  found  below  the 
snow  line  on  certain  bushes.  The  fungus  consists  of  bacilli  and  yeast- 
cells,  each  cell  containing  two  round  spores,  whence  the  name  Dispora 
caucasina.  When  dried,  the  kephir  fungus  forms  hard  yellowish  grains 
about  the  size  of  peas.  By  soaking  these  in  water  and  adding  them  to 
milk,  alcoholic  fermentation  ensues  and  the  kephir  is  matured  in  a  few 
days. 

The  following  figures  show  the  comparative  percentage  composition 
of  fresh  milk,  kephir,  and  koumiss : 


Fresh  Milk. 

Kephir. 

Koumiss. 

Fat              

3.8 

2.0 

2.05 

Proteids           

4.8 

3.8 

1.12 

Sugar   

4.1 

2.0 

2.20 

Lactic  acid  

Trace. 

0.9 

1.15 

Alcohol           

None. 

0.8 

1.65 

Water  and  salts  

87.3 

90.49 

91.83 

7.  CASEIN  PREPARATIONS. — Casein  is  now  utilized  on  a  large  scale, 
first,  as  a  basis  of  food  preparations ;  second,  as  a  fixing  agent  in  calico 
printing  instead  of  albumen;  and  third,  as  a  substitute  for  glue  in 
cements.  For  the  first  class  of  compounds,  the  casein  salts  of  the  alkalies 
and  alkaline  earths  are  used,  and  are  obtained  by  ^dissolving  casein  in  the 
calculated  amount  of  caustic  alkali,  alkaline  carbonate  or  phosphate  or 
milk  of  lime,  and  evaporating  the  solution  in  vacua.  The  products  are 
dry  white  powders.  For  the  second  class  of  compounds,  casein  is  gen- 


ANALYTICAL  TESTS  AND  METHODS.  293 

erally  dissolved  in  ammonia  or  in  borax  solution  and  used  either  with  or 
without  formaldehyde.  A  very  superior  paper  size  is  thus  made  which 
is  used  on  glazed  cardboard.  A  mixture  of  casein  with  slaked  lime  sets 
to  a  hard  insoluble  mass,  which  is  sometimes  employed  as  a  cement  for 
earthenware  and  for  similar  purposes  as  a  cheap  substitute  for  glue. 

In  making  these  casein  cements  the  most  important  point  that  is  to  be 
noteH  to  insure  success  is  the  freeing  of  the  casein  from  all  oily  matter. 
Therefore,  when  curd  is  prepared  from  milk,  use  only  the  most  carefully 
skimmed  milk  quite  free  from  cream,  such  as  separator  skimmed  milk. 
When  the  casein  has  been  separated  and  thoroughly  washed  it  is  uni- 
formly mixed  with  quicklime  and  applied  quickly.  It  then  sets  very 
rapidly.  Silicate  of  soda  solution  and  borax  are  also  used  instead  of 
quick-lime,  and  form  excellent  cements  with  casein.  Kdseleim  pulver,  a 
ready-made  Swiss  preparation,  will  set  when  moistened. 

8.  WHEY. — The  aqueous  liquid  remaining  after  the  separation  of  the 
butter-fat  and  the  casein,  or  curd,  is  termed  the  whey.  Its  more  im- 
portant constituent  is  milk-sugar,  which  in  sour  whey  has  been  changed 
in  part  into  lactic  acid.  It  also  contains  soluble  nitrogenous  constitutents, 
such  as  milk-albumen  and  peptonized  casein.  On  account  of  these  con- 
stituents it  is  an  easily  digestible  preparation  and  one  assisting  diges- 
tion. Hence  the  use  of  the  "whey  treatment  "  in  medical  practice  for 
dyspeptics  and  those  suffering  from  enfeebled  digestion.  The  chief  im- 
portance, however,  of  the  whey  is  for  the  extraction  of  the  milk-sugar, 
which  has  developed  into  an  important  article  of  manufacture.  Other 
products  of  minor  and  local  importance  only  are  ' '  whey  butter, "  "  whey 
alcohol,"  from  which  latter  "whey  champagne"  is  made,  and  "whey 
vinegar."  For  the  analysis  of  whey  see  p.  280. 

IV.  Analytical  Tests  and  Methods. 

1.  FOR  MILK. — The  specific  gravity  of  milk  is  an  indication  of  value, 
as  it  varies  according  to  the  content  of  fat,  being  higher  for  a  skimmed 
milk  than  for  a  whole  milk.  However,  when  the  cream  has  been  removed, 
the  specific  gravity  may  be  reduced  to  that  of  normal  milk  by  the  addi- 
tion of  water,  and  then  the  specific  gravity  determination  taken  alone 
would  be  fallacious.  Hence  the  detection  of  the  adulteration  of  milk  by 
addition  of  water  cannot  be  made  with  entire  accuracy  by  the  lactometer 
or  specific  gravity  hydrometer  in  use.  The  lactometer  officially  used  by 
milk  inspectors  in  New  York  and  other  States  indicates  specific  gravities 
between  1.000  (the  specific  gravity  of  water)  and  1.038.  A  specific 
gravity  of  1.021  (taken  as  the  minimum  density  of  genuine  milk)  is  also 
marked  100°,  while  the  specific  gravity  of  water  (1.000)  is  called  0°. 
Hence  if  the  lactometer  read  70°,  the  sample  is  supposed  to  contain 
seventy  per  cent,  pure  milk  and  thirty  per  cent,  water.  The  average 
lactometric  strength  of  about  twenty  thousand  samples  of  milk  examined 
by  the  New  York  State  Dairy  Commissioner  in  the  year  1884  was  110°, 
equivalent  to  a  specific  gravity  of  1.0319.  Another  form  of  lactometer 
used  abroad  is  the  Quevenne-Miiller  instrument,  which  is  graduated  in 
absolute  specific  gravity  readings  between  the  limits  1.014  and  1.042,  and 


294  MILK  INDUSTRIES. 

then  the  limits  of  pure  milk  (1.029  to  1.034)  indicated,  and  degrees  of 
dilution  with  water  also  indicated  as  the  specific  gravity  sinks  below  this. 
The  degree  of  adulteration  of  skimmed  milk  is  also  indicated  on  the 
instrument  in  the  same  way. 

The  total  solids  form  an  important  element  in  the  examination  of 
milk.  In  some  States  the  minimum  percentage  of  total  solids  allowed 
in  a  milk  is  stated  by  law.  (In  Massachusetts  thirteen  per  cent. ;  in  New 
York  and  New  Jersey  twelve  per  cent.)  To  determine  the  water  and 
total  solids,  five  grammes  of  milk  are  placed  in  an  accurately  weighed 
flat-bottomed  platinum  dish  of  not  less  than  five  centimetres  diameter  and 
dried  on  a  steam  bath  until  constant  weight  is  obtained.  Fifteen  to 
twenty  grammes  of  pure  dry  sand  may  be  previously  placed  in  the  dish 
to  facilitate  drying.  Cool  in  desiccator  and  weigh  rapidly  to  avoid 
absorption  of  moisture. 

To  determine  the  ash  weigh  about  twenty  grammes  of  milk  in  a 
weighed  dish,  add  six  cubic  centimetres  of  nitric  acid,  evaporate  to  dry- 
ness  and  ignite  at  a  temperature  just  below  redness  until  the  ash  is  free 
from  carbon. 

Both  fat  and  moisture  may  be  determined  with  one  weighing  of  the 
sample  in  the  Babcock  asbestos  method.  A  hollow  cylinder  of  perforated 
sheet  metal  sixty  millimetres  long  and  twenty  millimetres  in  diameter, 
closed  at  one  end  by  a  disk  of  the  same  material,  is  taken.  This  is  filled 
loosely  with  from  1.5  to  2.5  grammes  of  freshly  ignited  woolly  asbestos 
free  from  fine  and  brittle  material,  cooled  in  a  desiccator,  and  weighed. 
Then  introduce  a  weighed  quantity  of  milk  (between  three  and  five 
grammes)  and  dry  at  the  temperature  of  boiling  water  to  constant 
weight  to  obtain  the  moisture  by  loss.  Extract  the  residue  now  by  the 
aid  of  anhydrous  ether  until  all  the  fat  is  removed,  evaporate  the  ether, 
dry  the  fat  at  the  temperature  of  boiling  water  and  weigh.  The  fat  may 
also  be  determined  by  difference,  drying  the  extracted  cylinders  at  the 
temperature  of  boiling  water. 

The  paper  coil  method  of  Adams  is  also  often  used.  In  this  a  coil  of 
white  blotting-paper  (or  thick  filtering-paper)  previously  purified  with 
ether  and  dried  is  made  to  soak  up  the  milk  to  be  analyzed  from  a 
weighed  beaker  or  pipette.  The  paper  coil  is  then  dried  in  a  hot-air 
oven  and  placed  in  a  Soxhlet  (see  p.  86)  or  similar  fat-extraction  appa- 
ratus connected  with  an  inverted  condenser  and  the  fat  extracted  by 
ether  or  petroleum-ether. 

The  total  nitrogen  is  estimated  by  evaporating  a  weighed  portion  of 
milk  to  dryness  and  making  a  combustion  of  the  residue  with  soda-lime 
or  by  the  Kjeldahl  method  of  conversion  into  ammonia  compounds  and 
distillation  from  an  alkaline  solution.  Casein  may  be  determined  in 
fresh  milk  as  follows :  Place  about  ten  grammes  of  milk  in  a  beaker  with 
about  ninety  cubic  centimetres  of  water  at  40°  to  42,°  C.,  and  add  at  once 
1.5  cubic  centimetres  of  a  ten  per  cent,  acetic  acid  solution.  Stir  with  a 
glass  rod  and  let  stand  from  three  to  five  minutes  longer.  Then  decant 
on  to  the  filter,  wash  first  by  deeantation  and  then  transfer  the  precipi- 
tate to  the  filter  and  complete  the  washing.  The  nitrogen  is  determined 


ANALYTICAL  TESTS  AND  METHODS.  295 

in  the  washed  precipitate  and  filter  paper  by  the  Kjeldahl  method,  using 
6.38  as  the  factor  to  calculate  the  casein. 

The  estimation  of  the  milk-sugar  by  the  polariscope  is  rendered  diffi- 
cult by  the  presence  in  milk  of  various  albuminoids,  all  of  which  turn 
the  plane  of  polarization  to  the  left,  and  the  ordinary  means  of  removing 
these  albuminoids  by  a  solution  of  basic  acetate  of  lead  is  far  from  being 
perfect.  Professor  Wiley  after  extensive  experimentvS  upon  this  has 
adopted  a  method  of  optical  analysis,  using  acid  mercuric  nitrate  to 
precipitate  the  albuminoids.  He  takes  the  specific  rotatory  power  of 
milk-sugar  as  («)<*  =  52.5.  For  details  of  his  procedure  the  reader  is 
referred  to  Bulletin  107.*  Milk-sugar  may  also  be  determined  either 
volumetrically  or  gravimetrically  with  the  aid  of  Fehling's  solution. 
(See  p.  175.)  In  this  case,  it  is  also  necessary  to  remove  the  albuminoids 
first,  and  this  is  done  by  Ritthausen's  method  of  precipitation  with 
copper  sulphate,  all  excess  of  this  reagent  being  removed  with  caustic 
potash  solution.  In  calculating  the  results  it  will  be  remembered  that 
the  copper  reducing  power  of  milk-sugar  is  70.5°  as  compared  with 
dextrose  at  100°. 

The  sugar  is  probably  most  accurately  determined  by  extraction  from 
the  fat-free  residue  with  weak  boiling  alcohol,  filtering  the  alcoholic 
fluid,  and  evaporating  to  dryness.  This  leaves  the  sugar  with  some 
mineral  matter.  On  burning  and  determining  this  matter  as  ash  the 
amount  of  sugar  can  be  gotten. 

The  artificial  coloring  of  milk  is  frequently  practised  to  cover  up  the 
watering  of  the  sample.  The  colors  to  be  tested  for  are  annatto,  caramel 
and  anilin-orange,  an  azo-dye.  Leach  f  has  given  the  following  scheme 
for  the  detection  of  added  colors  in  milk: 

SUMMARY  OF  SCHEME  FOR  COLOR  ANALYSIS. — Curdle  one  hundred 
and  fifty  cubic  centimetres  of  milk  in  casserole  with  heat  and  acetic  acid. 
Gather  the  curd  in  one  mass,  pour  off  whey,  or  strain,  if  curd  is  finely 
divided.  Macerate  curd  with  ether  in  corked  flask.  Pour  off  ether. 

Ether  Extract.  Extracted  Curd. 

Evaporate  off  ether,  treat  with  NaOH  (1)  If  colorless — indicates  presence  of 

and  pour  on  wetted  filter.    After  the  solu-  no  foreign  color  other  than  in  ether  ex- 

tion  has  passed  through,  wash  off  fat  and  tract. 

dry  filter,  which  if  colored  orange,  indi-  (2)  If   orange  or  brownish — indicates 

rates  presence  of  annatto.     (Confirm  by  presence    of    anilin   orange   or   caramel. 

SriCl2. )  Shake  curd  in  test-tube  with  concentrated 

hydrochloric  acid. 

If  solution  gradually  If  orange  curd 

turns  blue,  indicative  immediately 

of  caramel.     (Confirm  turns   pink,  in- 

by  testing  for  caramel  dicative  of  ani- 

in    whey    of    original  lin  orange, 
milk.) 

The  examination  of  milk  for  preservatives  is  constantly  necessary. 
The  most  important  of  these  preservatives  is  formaldehyde.  To  detect 

»U.  S.  Dept.  of  Agricult.,  Bureau  of  Chem.,  Bulletin  107    (Revised),  p.  118. 
f  Food  Inspection  and  Analysis,  2d  ed.,  1909,  p.  177. 


296  MILK  INDUSTRIES. 

it  according  to  Leach  add  ten  cubic  centimetres  of  commercial  hydro- 
chloric acid  (specific  gravity  1.2)  containing  two  cubic  centimetres  of  ten 
per  cent,  ferric  chloride  per  litre  to  an  equal  volume  of  milk  in  a  porce- 
lain casserole  and  heat  slowly  over  the  free  flame,  giving  the  vessel  a 
rotatory  movement  while  heating  to  break  up  the  curd.  The  presence 
of  formaldehyde  is  indicated  by  a  violet  coloration  varying  in  degree 
with  the  amount  present.  With  fresh  milk,  one  part  of  formaldehyde 
in  250  of  milk  may  be  thus  detected. 

Hehner's  test  may  also  be  used.  To  five  or  ten  cubic  centimetres  of 
milk  in  a  wide  test-tube  add  about  half  the  volume  of  concentrated  com- 
mercial sulphuric  acid,  pouring  the  acid  carefully  down  the  inside  of  the 
tube  so  that  it  forms  a  layer  at  the  bottom  without  mixing  with  the  milk. 
A  violet  zone  at  the  junction  of  the  liquids  indicates  formaldehyde.  Ben- 
zoic,  salicylic,  and  boric  acids  have  also  been  used.  The  latter  may  be 
readily  tested  for  by  turmeric  paper.  Ten  cubic  centimetres  of  the  milk 
are  thoroughly  mixed  with  six  drops  of  concentrated  hydrochloric  acid. 
Turmeric  paper  moistened  with  this  and  dried  will  show  a  red  color  if 
boric  acid  were  present  in  the  milk. 

2.  FOR  BUTTER. — The  water  in  butter  is  determined  by  drying  five 
grammes  of  the  butter  in  a  platinum  dish  at  a  temperature  of  100°  C. 
(212°  F.)  or  slightly  higher.  The  melted  butter  is  stirred  from  time  to 
time  to  facilitate  the  escape  of  the  moisture.  The  water  will  have  been 
given  off  in  three  to  four  hours,  and  it  has  been  found  that  longer  heating 
sometimes  causes  the  melted  fat  to  gain  in  weight. 

To  determine  the  salt,  the  dried  butter  just  obtained  is  treated  with 
warm  ether  or  petroleum  spirit,  and  the  contents  of  the  platinum  dish 
poured  on  a  weighed  filter  and  washed  with  ether  until  all  fat  is  removed. 
The  residue  and  filter  are  dried  and  weighed.  The  salt  is  then  dissolved 
out  by  warm  water,  and  the  chlorides  in  the  solution  estimated  volumet- 
rically  by  titration  with  decinormal  silver  nitrate,  using  a  few  drops  of 
potassium  chromate  as  indicator.  The  difference  between  the  weight  of 
salt  ascertained  and  the  total  weight  of  curd  and  salt  on  the  weighed 
filter  is  regarded  as  the  amount  of  the  casein,  or  curd,  present.  If  after 
washing  out  the  salt  the  residue  on  the  weighed  filter  be  dried  and  then 
weighed,  the  amount  of  casein  so  obtained  is  a  little  less  than  that  gotten 
by  difference.  This  is  partly  due  to  the  small  amount  of  milk-sugar 
washed  out  along  with  the  salt  and  undetermined,  and  partly  to  the 
slight  solvent  action  of  warm  water  on  some  of  the  curd. 

The  percentage  of  fat  may  be  obtained  by  evaporating  the  ether 
filtrate  from  the  previous  determination  of  salt  and  curd,  but  the  butter- 
fat  is  liable  to  increase  in  weight  by  this  treatment,  and  therefore  the  fat 
is  usually  gotten  by  difference  after  determining  the  water,  casein,  salt, 
and  milk-sugar.  N 

The  adulteration  of  butter  and  the  manufacture  on  a  large  scale  of 
butter  substitutes  make  an  examination  of  the  butter-fat  one  of  great 
importance.  This  examination  may  be  both  qualitative  and  quantitative. 
The  butter-fat  is  gotten  for  examination  by  melting  a  sample  of  butter 


ANALYTICAL  TESTS  AND  METHODS.  297 

and,  after  allowing  the  water  and  curd  to  settle,  pouring  the  clear  fat  on 
to  a  dry  warm  ribbed  filter  and  collecting  the  filtrate. 

The  specific  gravity  of  the  butter-fat  may  be  taken,  as  first  suggested 
by  Bell,  in  a  specific  gravity  bottle  at  a  temperature  of  100°  F.  (37.7° 
C.),  or,  as  suggested  by  Estcourt  and  endorsed  by  Allen,  with  the  aid  of 
the  Westphal  balance  (see  p.  87)  at  a  temperature  of  99°  to  100°  C. 
(210°  to  212°  F.).  Bell  found  by  this  method  that  the  specific  gravity 
of  true  butter-fat  varied  from  909.4  to  914  (water  1000),  while  butterine 
showed  a  specific  gravity  of  901.4  to  903.8.  Allen  gives  the  limit  for 
pure  butter-fat  tested  at  99°  C.  as  867  to  870,  while  butterine  at  the 
same  temperature  was  858.5  to  862.5. 

The  melting  point  of  the  butter-fat  is  also  generally  noted.  Bell  pro- 
posed determining  the  melting  point  by  first  suddenly  cooling  some 
melted  butter-fat  by  floating  the  capsule  containing  it  upon  ice-water, 
and  then  taking  a  fragment  of  the  congealed  butter  upon  the  loop  of  a 
platinum  wire.  This  is  then  introduced  close  to  the  bulb  of  a  ther- 
mometer in  a  beaker  of  water  which  is  being  heated  from  without.  As 
the  water  becomes  warmed  the  globule  melts  and  the  thermometer  is 
read  off.  An  improvement  on  the  method  insuring  greater  accuracy  is 
recorded  in  Bulletin  No.  107  (revised)  of  the  Bureau  of  Chemistry,  p. 
133.  The  melting  point  of  butter  usually  ranges  between  29.5°  C.  and 
33°  C.  (85°  to  90°  F.),  while  the  melting  point  of  butterine  is  stated  to 
be  between  25.5°  C.  and  28°  C.  (77.9°  to  82.4°  F.). 

The  quantitative  examination  of  the  supposed  butter-fat  may  be  made 
by  several  methods, — viz.,  the  determination  of  the  saponification  equiv- 
alent by  Koettstorf er 's  method,*  the  determination  of  the  percentage  of 
insoluble  fatty  acids  present  as  glycerides  by  Hehner's  method,  f  and 
the  determination  of  the  volatile  fat  acids  after  distillation  by  Reichert  's 
method. \  To  these  most  generally  received  methods  may  also  be  added 
the  method  of  Hiibl  of  iodine  saturation  as  determining  the  character  of 
fatty  acids,  and  the  method  of  Morse  and  Burton,  which  combines  the 
Koettstorfer  and  the  Hehner  processes,  and  determines  the  saponification 
equivalent  of  the  soluble  and  the  insoluble  fat  acids  separately. 

The  term  "saponification  equivalent  "  is  used  to  indicate  the  number 
of  grammes  of  an  oil  saponified  by  one  equivalent  in  grammes  of  an  alkali. 
Thus,  tributyrin  (the  glyceride  of  butyric  acid)  has  a  saponification 
equivalent  of  100.67,  while  tristearine  (the  glyceride  of  stearic  acid)  has 
a  saponification  equivalent  of  296.67.  Butter-fat,  it  will  be  remembered, 
is  a  mixture  of  the  several  glycerides  of  the  lower  or  volatile  fatty  acids 
and  the  higher  or  non-volatile  fatty  acids.  Its  saponification  equivalent 
ranges  from  241  to  253,  the  average  being  247 ;  butterine  has  a  saponi- 
fication equivalent  ranging  from  277  to  294,  the  average  being  285.5.  In 
Hehner's  method,  the  weighed  quantity  of  the  fat  is  saponified  by  alco- 
holic potash,  the  soap  solution  evaporated  down,  taken  up  with  water, 

*  Allen,  Commercial  Organic  Analysis,  2d  ed.,  vol.  ii,  p.  40. 
t  Bell,  Analysis  and  Adulteration  of  Foods,  Part  ii,  p.  56. 
J  Allen,  Commercial  Organic  Analysis,  2d  ed.,  ii,  p.  45. 


298  MILK  INDUSTRIES. 

and  the  fatty  acids  set  free  by  an  excess  of  hydrochloric  acid.  They  are 
now  brought  upon  a  weighed  filter,  washed  with  boiling  water  until  no 
longer  acid,  and  then  chilled  into  a  cake  by  immersing  the  filter  in  cold 
water.  The  filter  is  then  transferred  to  a  weighed  beaker-glass  and  the 
contents  dried  at  100°  C.  until  constant  in  weight.  The  soluble  fat  acids 
can  also  be  determined  in  this  process  by  collecting  the  washings  which 
were  obtained  with  boiling  water  and  making  them  up  to  one  hundred 
cubic  centimetres  and  then  carefully  titrating  an  aliquot  portion  with 
decinormal  soda  solution.  This  will  give  the  amount  of  soluble  fat  acids 
plus  the  excess  of  standard  hydrochloric  acid  used  originally  in  liberating 
the  fat  acids.  The  amount  of  this  excess  can  be  ascertained  by  carrying 
through  a  blank  experiment  with  alcoholic  potash  and  hydrochloric 
acid,  but  without  the  fat.  In  the  analysis  of  butter-fat  the  sum  of  the 
insoluble  fatty  acids  and  of  the  soluble  fatty  acids  calculated  as  butyric 
acid  should  always  amount  to  fully  ninety-four  per  cent,  of  the  fat  taken. 
The  soluble  fatty  acids  calculated  as  butyric  acid  should  amount  to  at 
least  five  per  cent.,  any  notably  smaller  proportion  being  due  to  adultera- 
tion. As  an  average,  eighty-eight  per  cent,  of  insoluble  and  five  and  a 
half  per  cent,  of  soluble  acids  should  be  obtained. 

"While  the  true  percentage  of  the  volatile  fatty  acids  cannot  be  easily 
obtained,  the  amount  of  alkali  needed  to  neutralize  them  after  distillation 
can  be  determined  by  Reichert's  process.  According  to  this,  as  improved 
by  Meissl,  five  grammes  of  the  fused  and  filtered  fat  are  placed  in  a  flask 
of  about  two  hundred  cubic  centimetres  contents  with  about  two 
grammes  solid  caustic  potash  and  fifty  cubic  centimetres  of  seventy  per 
cent,  alcohol,  saponified  on  the  water-bath  and  evaporated  down  until  all 
alcohol  is  driven  off.  The  thick  soap-mass  remaining  is  now  dissolved 
in  one  hundred  cubic  centimetres  of  water,  forty  cubic  centimetres  of 
dilute  sulphuric  acid  added,  and,  after  adding  a  few  fragments  of 
pumice-stone,  distilled  with  the  aid  of  a  Liebig  condenser.  About  one 
hundred  and  ten  cubic  centimetres  of  distillate  are  collected,  which 
requires  about  an  hour.  Filter  and  collect  one  hundred  cubic  centimetres 
in  a  graduated  flask.  Add  phenol-phthalein  as  an  indicator,  and  titrate 
with  decinormal  alkali.  Increase  the  result  by  one-tenth,  and  reckon  the 
result  upon  five  grammes  of  the  substance.  It  is  found  that  two  and  a 
half  grammes  of  butter-fat,  examined  by  Reichert's  method,  require 
about  thirteen  cubic  centimetres  of  the  decinormal  alkali,  while  butterine 
requires  only  one  cubic  centimetre.  As  the  difference  between  these  is 
twelve  cubic  centimetres,  it  may  be  calculatd  that  there  is  8.5  per  cent, 
real  butter-fat  present  in  a  mixture  for  every  cubic  centimetre  of  alkali 
required  over  the  one  cubic  centimetre  required  for  ordinary  butterine. 

Hiibl's  method  is  founded  on  the  fact  that  the  three  series  of  fatty 
acids  (acetic,  acrylic,  and  tetrolic)  unite  in  different  proportions  with 
the  halogens,  like  chlorine,  bromine,  and  iodine, , to  form  addition  prod- 
ucts. The  number  of  grammes  of  iodine  absorbed  is  calculated  to  one 
hundred  grammes  of  fat,  and  this  is  Hiibl's  "iodine  number."  Thus 
genuine  butter  has  an  iodine  number  from  30.5  to  43.0,  while  oleomar- 
garine has  from  50.9  to  54.9. 


ANALYTICAL  TESTS  AND  METHODS.  299 

Morse  and  Burton  *  saponify  the  combined  fatty  acids,  liberate  the 
free  acids,  wash  out  the  soluble  portion  of  the  mixture,  and  then  saponify 
again  the  soluble  and  the  insoluble  acids  separately.  They  thus  combine 
the  Koettstorfer  and  the  Hehner  processes  and  get  a  greater  certainty 
as  to  the  character  of  the  fat  mixture.  Thus  they  find  that  with  butter 
86.57  per  cent,  of  potassium  hydrate  is  required  to  neutralize  the  insol- 
uble acids  and  13.17  per  cent,  to  neutralize  the  soluble  acids,  while  with 
oleomargarine  95.40  per  cent,  of  potassium  hydrate  is  required  for  the 
insoluble  acids  and  4.57  per  cent,  for  the  soluble  acids. 

A  physical  test  frequently  applied  to  distinguish  oleomargarine  and 
process  (renovated)  butter  from  true  butter  is  the  foam  test.  True 
butter  melted  in  a  spoon  over  a  free  flame  will  foam  abundantly,  while 
the  other  butter  named  will  only  burn  and  sputter  like  melted  grease. 

The  presence  of  annatto  coloring  in  butter  is  shown  by  treating  two 
or  three  grammes  of  the  melted  and  filtered  fat  (freed  from  salt  and 
water)  with  warm  dilute  sodium  hydroxide  and  after  stirring  pouring 
the  warm  mixture  upon  a  wet  filter.  If  annatto  is  present  the  paper  will 
absorb  the  color  so  that  when  the  fat  is  washed  off  by  a  gentle  stream  of 
water  the  paper  appears  dyed  straw  yellow  and  on  application  of  a  drop 
of  stannous  chloride  solution  turns  pink. 

For  azo  colors,  melt  a  small  amount  in  a  test-tube  and  add  an  equal 
amount  of  a  mixture  of  one  part  concentrated  sulphuric  acid  and  four 
parts  glacial  acetic  acid  and  heat  nearly  to  boiling,  shaking  the  contents 
of  the  tube.  Then  set  aside.  The  acid  solution  when  settled  will  show 
a  wine-red  color  in  the  presence  of  azo  colors. 

3.  FOR  CHEESE. — The  methods  employed  in  cheese  analysis  are  in 
most  respects  the  same  as  those  employed  in  the  examination  of  butter. 
The  fat  is  best  extracted  with  light  petroleum-ether,  as  common  ether 
dissolves  the  free  lactic  acid  as  well  as  the  fat.  The  remaining  solids 
not  fat  can  then  be  dried  and  weighed.  The  fat  should  be  examined  by 
Koettstorfer 's  saponification  equivalent  method,  as  the  oleomargarine 
and  lard  cheeses  may  be  detected  in  this  way.  Genuine  cheese-fat,  accord- 
ing to  Muter,  f  should  not  consume  less  than  two  hundred  and  twenty 
milligrammes  of  potassium  hydrate  for  each  gramme  used.  If  the  cheese 
should  give  unfavorable  indications  with  Koettstorfer 's  test,  then  the 
soluble  and  insoluble  fatty  acids  are  determined  in  the  fat  according  to 
Hehner.  The  percentage  of  insoluble  fat  acids  in  genuine  cheese,  accord- 
ing to  Muter,  averages  88.5,  while  in  oleomargarine  cheeses  it  is  from 
90.5  to  92  per  cent. 

The  acidity,  calculated  as  lactic  acid,  may  be  determined  by  treating 
the  residue  from  the  fat  determination  with  water  and  titrating  the 
washings  with  decinormal  soda  solution.  The  washed  residue  then  is 
the  non-fatty  solids. 

The  ash  is  determined  by  ignition  of  the  dried  cheese  before  extrac- 
tion of  the  fat. 

*  Amer.  Chem.  Journ.,  x,  p.  322. 
t  Analyst,  vol.  x,  p.  3. 


300  MILK  INDUSTRIES. 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

1878. — Butter,  its  Analysis  and  Detection,  Angell  &  Hehner,  2d  ed.,  London. 

Illustrirtes   Lexikon   der   Verfalschungen   der    Nahrungsmittel,   H.   Kluncke, 

Leipzig. 
1882. — Food  Sources,  Constituents,  and  Uses,  A.  H.  Church,  London. 

Chevallier's  Dictionnaire  dee  Alterations  et  Falsifications,  6me  eM.,  Baudri- 

mont,  Paris. 

The  Analysis  of  Milk,  Condensed  Milk,  etc.,  N.  Gerber,  New  York. 
1884. — Falsifications  des  Mati&res  aliraentaires,  Laboratoire  Municipal,   Paris. 

Die  Conservirung  von  Milch,  Eier,  etc.,  C.  Heinzerling,  Halle. 
1885. — Fabrikation  von  Kunstbutter,  V.  Lang,  2te  Auf.,  Leipzig. 
1886. — Ueber  Kunstbutter,  ihre  Herstellung,  etc.,  Eugen  Sell,  Berlin. 
Milk  Analysis,  J.  Alfred  Wanklyn,  2d  ed.,  London. 
Die  Analyse  der  Milch,  E.  Pfeiffer,  2d  ed.,  Wiesbaden. 
Des  Laits  fermented  et  leurs  Usages,  Saillet,  Paris. 
1887. — Food  Adulteration  and  its  Detection,  J.  P.  Battershall,  New  York. 

United  States  Department  of  Agriculture,  Bulletin  No.  13,  Part  i.    (Dairy 

Products),  H.  W.  Wiley,  Washington. 
United    States    Department   of   Agriculture,    Bulletin    No.    16    (Methods   of 

Analysis  of  Dairy  Products,  etc.),  C.  Richardson,  Washington. 
Le  Lait,  fitudes  chimiques  et  Microbiologiques,  Duclaux,  Paris. 
Illustrirtes  Lexikon  der  Verfalschungen,  etc.,  Dammer,  Leipzig. 
1888. — United    States    Department   of   Agriculture,    Bulletin   No.    19    (Analysis   of 

Dairy  Products),  C.  Richardson,  Washington. 

Foods,  their  Composition  and  Analysis,  2d  ed.,  A.  W.  Blyth,  London. 
1889. — Chemie  der  Menschlichen  Nahrungs-  und  Genussmittel,  J.  Konig,  3te  Auf., 

Berlin. 

La  Margarine  et  le  Beurre  artificiel,  Girard  et  Brevans,  Paris. 
1891. — Die  Untersuchung  landwirthschaftlich  wichtiger  Stoffe,  J.  Konig,  Berlin. 

Handbuch  der  Milchwirthschaft,  Kirchner,  3te  Auf.,  Berlin. 
1893. — Trait§  g€n€ral  d'Analyse  des  Beurres,  2  tomes,  A.  J.  Zune,  Paris. 

Dairy  Chemistry  for  Dairy  Managers,  H.  D.  Richmond,  London. 
1894. — Milk,  Cheese,  and  Butter:   a  Practical  Handbook,  J.  Oliver,  London. 
1895. — Dairy  Bacteriology,  E.  von  Freudenreich,  translated  by  J.  R.  Davis,  London. 
1896. — The  Analysis  of  Milk  and  Milk  Products,  Leffman  and  Beam,  2d  ed.,  Phila- 
delphia. 
The  Book  of  the  Dairy,  W.  Fleischmann,  translated  by  Aikman  and  Wright, 

London. 

1897. — The  Chemistry  of  Dairying,  Harry  Snyder,  Easton,  Pa. 
1898. — Testing  Milk  and  its  Products,  Farrington  and  Woll,  3d  ed.,  Madison,  Wis. 
1899. — Milk,  its  Nature  and  Composition.     A  Handbook.     C.  M.  Aikman,  2d  ed., 

New  York. 

Dairy  Chemistry:  a  Practical  Handbook,  H.  D.  Richmond,  London. 
1903. — Milk,  its  Production  and  Uses,  E.  F.  Willoughby,  London. 
1906. — Casein,  its  Preparation  and  Technical  Utilization,  R.  Scherer,  translated  by 

Chas.  Salter,  London. 
1909.— Milk  Analysis  by  J.  Wanklyn,  New  Ed.,  by  W.  J.  Cooper,  London. 

The  Science  and  Practice  of  Cheesemaking,  L.  L.  van  Slyke  and  C.  A.  Publow. 
1910. — Chemie  und  Physiologic  der  Milch,  W.  Grimmer,  Paul  Parey,  Berlin. 

> 

STATISTICS. 

The  only  general  statistics  of  the  milk  industry  are  those  gathered 
for  the  Census  Bureau  in  1905,  those  for  1910  being  not  as  yet  avail- 


BIBLIOGRAPHY  AND  STATISTICS. 


301 


1900. 

Increase. 

$130,783,349 

$37,399,400 

420,126,546 

111,351,595 

$84,079,754 

$29,109,699 

281,972,324 

35,172,548 

$26,519,829 

$2,091,931 

186,921,787 

121,563,395 

$11,888,792 

$8,260,490 

$8,294,974 

$2,062,680 

able.     The  figures  for  the  main  products  of  the  milk  industry  are  as 
follows : 

1905. 

Products,  total  value   $168,182,789 

Butter    (Ibs.)     531,478,141 

Value    $113,189,453 

Cheese    (Ibs.)     317,144,872 

Value    $28,611,760 

Condensed  milk   (Ibs.)    308,485,182 

Value     $20,149,282 

All  other  products $6,232,294 

(Report  of  Census  Bureau,  1905.) 

The  oleomargarine  production,  as  reported  by  the  Internal  Revenue 
Bureau,  has  been: 

1909.  1910. 

Uncolored   oleomargarine    (Ibs.)     86,572,514  135,685,289 

Colored  oleomargarine    (Ibs.)    5,610,301  6,176,991 

Total  oleomargarine    (Ibs.)    92,282,815  141,862,282 

The  exportation  of  dairy  products  from  the  United  States  has  de- 
creased in  recent  years  and  was  as  follows: 


1906.         1907.         1908.         1909. 

Butter    (Ibs.)    27,360,537  12,544,777       6,463,061       5,981,265 

Valued  at  $4,922,913  $2,429,489  $1,407,962  $1,268,210 

Cheese  (Ibs.)  16,562,451  17,285,230  8,439,031  6,822,842 

Valued  at  $1,940,620  $2,012,626  $1,092,053  $857,091 

Oleomargarine  (Ibs.)  .  11,794,174  5,397,609  2,938,175  2,889,058 

Valued  at  $1,033,256  $520,406  $299,746  $293,746 

Oleo  oil  (Ibs.)  209,658,075  195,337,176  212,541,157  179,985,246 

Valued  at  $17,455,976  $16,819,933  $19,278,476  $19,126,745 

Condensed  milk  (Ibs. )  

Valued  at    $1,889,690 


5,191,111     $2,455,186     $1,375,104 


1910. 

3,140,545 

$785,771 

2,846,209 

$441,017 

3,418,632 

$349,972 

126,091,675 

$14,305,080 

13,311,318 

$1,023,633 


Of  miscellaneous  products,  there  were  produced  in  1905,  according 
to  the  Census  Bureau,  1,161,414,457  pounds  of  skimmed  milk  valued  at 
$1,368,738,  and  from  this  was  extracted  11,581,874  pounds  of  casein, 
valued  at  $554,099.  The  whey  from  which  sugar  of  milk  is  obtained 
amounted  to  166,451,226  pounds,  valued  at  $111,907. 


302  VEGETABLE  TEXTILE  FIBRES. 


CHAPTER    VIII. 

VEGETABLE   TEXTILE   FIBRES. 

General  Characters. 

ALL  the  fibres  which  have  been  found  of  technical  value  for  manu- 
facturing purposes  may  be  divided  into  the  two  great  classes,  vegetable 
fibres  and  animal  fibres,  the  few  found  in  the  mineral  kingdom  among 
fibrous  minerals  being  of  relatively"  slight  importance  in  textile  manu- 
facturing. Moreover,  the  distinction  is  not  merely,  as  the  name  chosen 
would  indicate,  one  of  origin,  but  fundamental  structural  and  chemical 
differences  also  exist  and  make  themselves  evident  upon  the  slightest 
examination.  The  vegetable  fibres  are  exclusively  cell-growths  of  rela- 
tively simple  structure,  which  during  their  life  form  integral  parts  of 
the  plant  organisms,  while  the  animal  fibres  may  be  either  a  hardened 
secretion  like  silk  or  a  more  complicated  cell-growth  like  wool,  distin- 
guished by  its  scale-like  surface. 

Thus  the  vegetable  fibres  are  without  exception  some  form  of  cellu- 
lose (C0H1005)n  in  more  or  less  pure  condition  or  an  alteration  product 
of  the  same,  while  the  animal  fibres  are  composed  of  protein  matter,  and 
hence  are  nitrogenous. 

The  radical  character  of  their  chemical  difference  just  referred  to 
will  be  more  thoroughly  appreciated  when  we  note  the  action  of  reagents 
upon  the  two  classes  respectively.  The  vegetable  fibres  are  not  dissolved 
or  weakened  by  alkalies  even  at  a  boiling  temperature,  while  the  animal 
fibres  are  speedily  disintegrated,  with  eventual  liberation  of  ammonia 
from  the  nitrogenous  material;  on  the  other  hand,  sulphuric  acid  or 
hydrochloric  acid  rapidly  causes  a  disintegration  of  the  vegetable  fibres 
by  their  action  upon  the  cellulose,  and  nitric  acid  either  oxidizes  the 
cellulose  or  gives  rise  to  nitrated  derivatives,  while  the  animal  fibres 
are  only  slightly  affected  even  when  the  acids  are  concentrated.  These 
reactions  will  be  referred  to  more  fully  in  speaking  of  the  analytical 
tests  used  for  distinguishing  the  fibres  in  mixed  goods.  (See  p.  353.) 

The  several  vegetable  fibres  may  be  classified  according  to  botanical  or 
morphological  character  into  three  groups:  (1)  Seed-hairs  (filaments 
composed  of  individual  cells)  ;  (2)  bast  fibres  (filaments  or  fibre-bundles 
made  up  of  individual  fibre-cells  aggregated  together)  ;  and  (3)  fibro- 
vascular  bundles.  Sometimes  the  term  bast  fibres  is  made  to  include 
both  the  second  and  third  classes  as  just  given. 

Chemically,  all  vegetable  fibres  are  composed  "of  cellulose.  However, 
it  has  long  been  known  that  it  is  frequently  more  or  less  contaminated 
with  altered  products,  which  have  been  known  as  lignin,  ligno-cellulose, 
adipo-cellulose,  etc.  The  recent  researches  of  Messrs.  Cross  and  Bevan 


GENERAL  CHARACTERS.  303 

have  given  us  a  clear  understanding  of  the  nature  of  the  lignin  and  the 
alteration  products  of  cellulose.  The  combination  of  cellulose  and  lig- 
nin, to  which  they  apply  the  name  of  bastose,  may  make  up  the  whole 
bundle  of  fibres,  as  in  jute,  or  may  be  merely  a  covering  upon  the  unal- 
tered cellulose.  By  distinguishing  between  the  cellulose  and  the  bastose 
and  mixtures  of  the  two  we  may  establish  a  chemical  classification  of  the 
vegetable  fibres.  We  are  enabled  to  do  this  by  the  aid  of  the  solutions  of 
iodine  (potassium  iodide  solution  saturated  with  free  iodine)  and  sul- 
phuric acid  (concentrated  glycerine  and  strong  sulphuric  acid),  which 
were  first  proposed  by  Vetillart.*  Pure  cellulose  when  tested  with  the 
iodine  and  sulphuric  acid  solutions,  one  after  the  other,  will  give  a  pure 
blue  color,  while  bastose  shows  under  these  conditions  a  yellow  colora- 
tion. A  complete  classification,  taking  both  botanical  and  chemical  char- 
acters into  account,  is  the  following,  which  is  that  of  Cross  and  Sevan 's  f 
with  some  additions: 

A.  B.  c. 

Seed-hairs.             Dicotyledonous  Monocotolydonous  fibres  cor- 

bast  fibres.  responding  to  bast  fibres. 

Linen.  Straw. 

Hemp.  Pineapple. 


Blue  reaction    with    iodine  < 
and  sulphuric  acid. 


Yellow  reaction  with  iodine 
and  sulphuric  acid. 


Cotton.  China-grass.  Esparto. 

Kamie.  Alfa. 

Nettle. 
Sunn  fibre. 

New  Zealand  flax. 

Aloe. 

Hibiscus.  Yucca. 

Jute.  Manila  hemp. 

Coir. 


1.  COTTON  FIBRE. — The  cotton,  as  already  noted,  is  a  seed-hair  and 
envelops  the  seeds,  which  are  at  first  enclosed  in  a  capsule.  With  the 
ripening  of  the  plant  this  capsule  bursts  and  the  contents  spread  out 
widely,  consituting  the  cotton-boll,  which  is  easily  picked.  The  separa- 
tion of  the  fibre  from  the  enclosed  seed  is  afterwards  accomplished  by 
the  mechanical  operation  called  "ginning,"  in  which  it  is  torn  from  the 
seed,  so  that  while  one  end  of  an  individual  fibre  is  always  closed  the 
other  is  irregularly  broken. 

The  genus  Gossypium,  to  which  all  cotton-plants  are  referred,  in- 
cludes several  well-marked  varieties,  the  most  important  of  which  are 
G.  Barbadense,  or  "sea-island  cotton,"  grown  off  the  coast  of  Georgia, 
South  Carolina,  and  Florida,  which  yields  the  longest  and  strongest  fibre 
or  the  finest  ' '  staple ; ' '  the  G.  hirsutum,  or  upland  cotton,  grown  inland 
in  Georgia,  Alabama,  Louisiana,  and  Mississippi,  which  yields  a  shorter 
staple;  the  G.  herbaceum,  grown  in  Egypt,  Asia  Minor,  and  India;  the 
G.  Barbadense,  or  "sea-island  cotton,"  grown  off  the  coast  of  Georgia, 
China  and  India  and  yielding  the  so-called  "nankin  "  cotton  of  brown- 
yellow  color ;  and  the  G.  Peruvianum,  yielding  the  long-stapled  Brazilian 
and  Peruvian  cotton. 

The  structure  of  the  cotton  fibre  is  very  characteristic.    It  presents  a 

*  Vetillart,  Etudes  pur  les  Fibres,  Paris,  1876. 
t  Text-book  of  Paper-Making,  p.  46. 


304 


VEGETABLE  TEXTILE  FIBRES. 


flattened  and  collapsed  tube  slightly  twisted  in  spiral  form,  with  com- 
paratively thick  walls  and  a  small  central  opening.  This  structure  is 
illustrated  in  Figs.  75  and  76,  in  the  first  of  which  the  fibre  is  magnified 
thirty  times  and  in  the  second  of  which  it  is  magnified  two  hundred 
times.  The  first  illustration  shows  the  spiral  twist  of  the  fibres  distinctly, 
but  the  collapsed  character  of  the  tube  only  slightly ;  this  latter  feature, 
however,  is  shown  very  distinctly  in  the  second  illustration.  This  flat- 
tening is  not  seen  in  the  unripe  fibre,  which  is  a  tube  filled  with  liquid 
protoplasmic  matter,  but  in  the  ripening  of  the  plant  this  liquid  dries 
up  and  the  walls  of  the  tube  collapse  and  flatten  out.  The  adhesion  of 
the  fibre  to  the  seed  also  becomes  less,  so  that  the  ripe  cotton  is  easily 
separated  in  the  ginning  process.  In  some  species  (as  in  G.  Barbadense] 
this  separation  of  hair  from  the  seed  is  so  perfect  that  the  seed  shows 


FIG.  75. 


FIG.  76. 


after  the  ginning  a  lustrous  black  appearance,  whence  the  name  locally 
applied  of  "  black-seed  cotton  "  as  distinguished  from  the  upland 
variety,  known  as  "green-seed  cotton." 

The  fibre  must  be  picked  when  mature  or  it  becomes  ' '  over-ripe  ' '  and 
deteriorates.  The  length  of  the  "staple,"  or  fibre,  varies  considerably 
with  the  different  varieties  of  the  cotton,  the  long-stapled  sea-island 
cotton  grown  on  the  shores  of  Georgia  and  Florida  attaining  a  length 
of  nearly  two  inches  (five  centimetres),  while  the  short  native  cotton  of 
India  scarcely  exceeds  three-quarters  of  an  inch  (eighteen  millimetres) 
in  length.* 

Chemically,  the  cotton  fibre  contains  about  ninety-one  per  cent,  of 
pure  cellulose,  seven  per  cent,  of  moisture,  and  small  amounts  of  fat, 
nitrogenous  material,  and  cuticular  substance.  An  ammoniacal  solution 
of  copper  oxide  causes  the  cellulose  material  of  the  fibre  to  soften  and 
swell  up,  whereby  the  cuticle,  which  is  not  softened,  takes  the  appearance 
of  yellowish  constricting  rings  binding  the  swollen  cellulose  at  regular 
intervals.  Prolonged  action  of  the  reagent  dissolves  the  cellulose.  When 


Bowman,  Structure  of  the  Cotton  Fibre,  p.  19. 


GENERAL  CHARACTERS. 


305 


FIG.  77. 


5  a  i 

a 


2   4 


bleached  by  boiling  with  sodium  carbonate  or  hydrate,  the  cuticle  is 
decomposed  and  the  fibre  yields  easily  a  very  pure  form  of  cellulose. 

2.  FLAX. — The  flax-plant,  Linum  usitatissimum,  yields  the  best 
known  and  probably  the  most  valuable  of  the  bast  fibres  as  well  as  other 
products,  like  the  linseed  oil  and  linseed  cake.  (See  p.  54.)  It  is  not 
grown  for  both  fibre  and  seed  together,  however,  as  when  the  fibre  is 
desired  in  best  condition  the  plant  is  gathered  before  it  is  fully  matured, 
while  if  the  plant  is  allowed  to  ripen  fully  for  production  of  seed,  the 
fibre  obtained  is  more  stiff  and  coarse. 

The  plant  is  grown  through  a  wide  range  of  climate,  although  that 
grown  in  the  tropics,  as  in  India,  is  chiefly  used  for  seed,  the  fibre  being 
of  little  value,  while  that  grown  in  colder  countries,  as  in  the  Russian 
East  Sea  provinces,  yields  the  best  fibre.  When  the  plant  is  cultivated 
for  the  production  of  fibre,  it  is  either  sowed  more  thickly  or,  as  in  Hol- 
land and  Belgium,  forced  to  grow  up 
through  a  net-wrork  of  brushwood,  thus 
yielding  a  more  slender  plant  with  a  longer 
and  finer  fibre,  known  as  tin  rame.  The 
plant  is  not  cut,  but  is  always  carefully 
pulled  up  by  the  roots,  and  the  freshly 
pulled-up  flax  is  at  once  submitted  to  the 
process  of  seeding,  or  ' '  rippling, ' '  which  is  to  remove  the 
leaves  and  seed  capsules.  This  is  usually  done  by  hand, 
drawing  the  bundles  of  the  flax  through  upright  metallic 
combs,  or  "ripples,"  the  prongs  of  which  easily  catch  the 
seed  capsules,  so  that  three  or  four  drawings  suffice  to 
clean  the  stems  or  flax  straws. 

This  straw,  as  it  is  termed,  contains  in  a  dried  condi- 
tion seventy-three  or  eighty  per  cent,  of  its  weight  of 
woody  matter  and  encrusting  material  and  twenty  to  twenty-seven  per 
cent,  of  bast  fibre. 

The  distinction  between  the  several  parts  of  the  stem  in  the  flax  and 
similar  plants  yielding  bast  fibres  is  shown  in  Fig.  77  by  both  transverse 
and  longitudinal  cross-sections,  where  1  represents  the  pith,  2  the  woody 
tissue,  3  the  cambium  or  partially  lignified  tissue,  4  the  bast  fibre,  and  5 
the  crust  or  rind.  To  free  these  several  parts  of  the  stem  from  each 
other  so  as  to  obtain  in  a  clean  state  the  bast  fibre  is  the  object  of  the 
process  of  "retting."  This  is  done  either  by  natural  means,  as  in  the 
case  of  dew  retting  and  cold-water  retting,  or  by  the  help  of  an  artificial 
process,  as  in  warm-water  retting  and  chemical  retting.  The  dew  ret- 
ting, applied  most  largely  in  Russia,  consists  in  leaving  the  flax  thinly 
spread  exposed  to  dew  and  rain,  air  and  light,  for  eight  or  ten  weeks, 
when,  by  the  fermentation  of  the  pectose  matter  of  the  rind,  the  bast 
fibre  is  thoroughly  loosened.  In  cold-water  retting  either  running  or 
stagnant  water  may  be  used,  the  former  being  used  in  Belgium  and  the 
latter  in  Ireland.  The  bundles  of  flax  are  placed  in  crates  and  sub- 
merged, when  actual  fermentation  ensues.  The  water  must  be  soft,  and 
care  must  be  taken,  especially  in  the  stagnant-water  method,  to  prevent 

20 


306 


VEGETABLE  TEXTILE  FIBRES. 


undue  heating  up  during  the  fermentation.  The  warm-water  retting 
requires  a  temperature  of  30°  to  35°  C.,  and  can  be  carried  to  comple- 
tion in  fifty  to  sixty  hours,  yielding  an  excellent  product.  The  chemical 
process  consists  in  the  use  of  dilute  sulphuric  acid  or  hydrochloric  acid, 
which  allow  of  the  completion  of  the  process  in  a  few  days.  After  the 
retting  process  the  flax  is  well  washed  and  dried,  and  is  then  submitted 
to  the  mechanical  processes  of  "breaking,"  "scutching,"  and  "hack- 
ling" to  thoroughly  free  the  fibre  from  the  woody  layer  and  draw  out 
the  fibre-bundles  into  filaments. 

The  flax  fibre  as  seen  under  the  microscope  seems  to  be  a  long  straight 
and  transparent  tube  with  thick  walls  and  a  minute  central  canal.    Fig. 


FIG.  79. 


FIG.  78. 


Flax  (3f«). 


Heinp  ( 


78  shows  these  characters  of  the  flax  fibre.  Characteristic  transverse 
markings  also  are  shown,  which  may  be  nodal  divisions  or  slight  breaks 
or  wrinkles  produced  by  bending.  Longitudinal  fissures  also  show  after 
vigorous  rubbing.  The  linen  fibre  when  cleansed  has  a  blonde  or  even 
white  color,  a  fine  silky  lustre,  and  great  strength.  It  is  less  pliant  and 
elastic  than  cotton,  but  is  a  better  conductor  of  heat,  and  hence  seems 
colder  than  cotton.  Chemically  it  is,  like  cotton,  a  pure  cellulose,  but 
when  swollen  by  the  action  of  ammoniacal  cupric  oxide  solution  does  not 
show  the  same  uniform  series  of  constricting  bands  of  cuticle.  Linen 
is  in  many  respects  more  readily  disintegrated  than  cotton,  especially 
under  the  influence  of  caustic  alkalies,  calcium^  hydrate,  and  strong  oxi- 
dizing agents  like  chlorine  and  hypochlorites. 

3.  HEMP. — The  fibre  known  by  this  name  is  the  product  of  the  Can- 
ndbis  sativa,  which  is  grown  for  textile  purposes  chiefly  in  Russia  and 


GENERAL  CHARACTERS. 


307 


Italy,  while  the  seed  is  grown  in  India.  It  is  a  bast  fibre  similar  to  that 
of  the  flax-plant,  but  coarser,  stronger,  of  deeper  color  and  less  lustre. 
Fig.  79  shows  the  microscopical  characters  of  the  hemp  fibre.  Its  culti- 
vation is  very  similar  to  that  already  described  under  flax,  and  differs 
according  as  the  fibre  or  the  seed  are  sought.  The  freshly-plucked  hemp 
loses  sixty  per  cent,  of  its  weight  in  drying,  and  from  the  air-dried  hemp 
straw  twenty  per  cent,  of  bast  fibre  is  obtained  in  the  case  of  the  male 
plant  and  twenty-two  per  cent,  in  the  case  of  the  female  plant.  It  is  used 
chiefly  for  ropes  and  cordage,  and  the  fabric  woven  from  it,  known  as 
canvas,  is  used  in  sail-making.  Much  of  the  finer  fibre,  however,  is  com- 
bined with  linen  fibre  in  weaving  other  goods.  The  iodine  and  sulphuric 
FIG.  80. 


FIG.  81. 


Jute,  Corchorus  capsularis  (*!°). 


acid  test  shows  that  the  hemp  fibre  is  not  composed  of  pure  cellulose,  but 
is  a  mixture  of  cellulose  and  bastose. 

4.  JUTE  is  the  bast  fibre  of  two  species  of  the  genus  Corchorus,  and 
is  grown  chiefly  in  India  and  Ceylon.  The  fibre  is  separated  from  the 
plant  by  methods  similar  to  those  employed  with  flax  and  hemp,  the 
process  of  cold  retting  in  stagnant  water  being  followed  generally.  The 
bast  fibres  attain  a  length  of  2.5  metres  or  even  more,  are  of  a  yellowish- 
white  color,  and  have  a  fine  lustre.  It  is  seen  under  the  microscope  to 
consist  of  bundles  of  stiff  lustrous  cylinders  with  walls  of  very  irregular 
thickness.  These  'characters  of  the  jute  are  shown  in  Fig.  80.  Chem- 
ically, jute  differs  from  the  bast  fibres  hitherto  mentioned  in  that  it 
contains  no  free  cellulose,  but  consists  of  the  chemical  compound  of 
cellulose  with  lignin,  to  which  Cross  and  Bevan,  who  investigated  it, 
gave  the  name  of  bastose.  It  gives,  treated  with  iodine  and  sulphuric 
acid,  a  deep  brown  color.  Moreover,  the  bastose  acts  with  basic  dye 


308  VEGETABLE  TEXTILE  FIBRES. 

colors,  like  the  aniline  dyes,  as  if  it  had  been  mordanted  with  tannin, 
and  can  therefore  be  dyed  directly  without  previous  treatment.  It  is 
much  more  easily  affected  by  the  action  of  acids  and  alkalies  than  flax 
or  hemp.  The  influence  of  air  and  moisture  will  also  rot  the  jute  fibre. 
It  cannot  be  bleached  safely  with  chloride  of  lime  because  of  the  readi- 
ness with  which  the  fibre  is  oxidized,  but  it  may  be  bleached  with  a  weak 
solution  of  sodium  hypochlorite  or  by  the  successive  action  of  potassium 
permanganate  and  sulphurous  acid.  It  may  be  considered  as  showing 
more  resemblance  to  the  animal  fibre  in  lustre  and  appearance  than  any 
of  the  other  vegetable  fibres,  and  is  therefore  frequently  mixed  with 
wool,  mohair,  and  silk  in  certain  classes  of  goods. 

Among  the  fibres  of  lesser  importance  which  serve  as  substitutes  for 
hemp  and  jute  are  Manila  hemp,  Sunn  hemp,  and  Sisal  hemp.  The  first 
of  these  is  a  tropical  fibre,  obtained  on  the  Philippine  Islands  from  the 
leaves  of  the  wild  plantain.  The  fibre  is  obtained  by  cutting  open  the 
leaf-stalks,  which  are  from  six  to  nine  feet  in  length,  and  then  scraping 
them  free  from  pulpy  matter.  It  furnishes  a  very  superior  rope-making 
fibre  because  of  its  combined  lightness  and  strength,  and  the  finer  grades 
are  used  for  woven  goods.  The  color  is  yellowish  or  white,  and  the 
white  variety  has  a  fine  silky  lustre.  It  is  shown  in  Fig.  81. 

The  Sunn  hemp  is  grown  in  India,  and  furnishes  a  fibre  of  light- 
yellowish  color  and  resembles  jute,  although  less  lustrous.  It  is  well 
adapated  for  cordage  and  netting. 

Sisal  hemp  (or  henequen)  is  derived  from  the  fleshy  leaves  of  a 
species  of  agave  grown  in  Yucatan,  British  Honduras,  and  the  West 
Indies  and  Bahamas.  It  is  used  largely  in  the  United  States  as  a  sub- 
stitute for  jute  in  the  manufacture  of  bagging  and  for  cordage,  being 
stronger  and  lighter  than  jute. 

Ramie  fibre  (China-grass}. — The  bast  fibre  from  two  varieties  of 
Boehmeria  nivea,  known  in  India  as  Rhea,  in  the  Malay  Archipelago  as 
Ramie,  and  to  Europeans  as  China-grass,  has  in  recent  years  attracted 
very  favorable  attention  from  all  interested  in  textile  industries.  It 
seems  to  thrive  best  in  the  tropics  and  requires  a  great  deal  of  moisture. 
The  bast  fibre  cannot  be  removed  from  the  woody  stems  by  the  retting 
process  used  for  flax  and  hemp,  as  the  intercellular  substance  is  so  easily 
decomposed  that  the  water  retting  rapidly  resolves  the  fibre  into  a 
magma  of  separated  cells.  The  fibre  must  be  removed  from  the  woody 
stem  while  the  plants  are  in  the  green  state,  as  when  dried,  even  by 
several  hours'  exposure  to  the  sun,  the  fibre  becomes  difficult  to  remove 
from  the  woody  portion.  The  length  of  the  cells  makes  it  possible  to  cut 
the  ramie  fibre  into  short  lengths  and  to  treat  the  cleansed  fibre  like 
cotton  rather  than  like  a  long  bast  fibre.  Hence  the  name  "cottonized" 
ramie  which  has  been  applied  to  that  exported  from  China.  With 
improved  methods  it  is  found  possible  to  cleanse  it  in  full  lengths,  and 
the  fibre  is  worked  like  flax  rather  than  with  cotton-spinning  machinery. 
The  machines  for  breaking  and  decorticating  the  ramie  are  numerous, 
but  few  if  any  are  entirely  satisfactory.  The  properly-prepared  fibre 
is  of  fine  silky  lustre,  soft,  and  extraordinarily  strong.  It  is  undoubt- 


GENERAL  CHARACTERS. 


309 


FIG.  82. 


edly  the  most  perfect  of  all  the  vegetable  fibres,  and  will  play  a  great 
part  in  the  industries  of  the  future,  especially  as  the  plant,  being  a 
perennial,  can  be  grown  continuously  for  years,  spreading  of  itself  very 
rapidly  and  yielding  several  crops  yearly.  Its  cultivation  has  been 
begun  successfully  in  Louisiana  and  Mississippi,  and  it  can  probably  be 
extended  through  the  Southern  States  and  Mexico,  where  is  has  also  been 
tried.  The  iodine  and  sulphuric  acid  test  shows  the  ramie  fibre  to  be 
composed  of  a  pure  cellulose,  which  swells  easily  and  voluminously  when 
treated  with  ammoniacal  solution  of  cupric  oxide.  The  appearance  of 
the  China-grass  is  shown  in  Fig.  82. 

Nettle  Fibre.— The  bast 
fibres  of  the  common  nettle 
(Urtica  dioica)  were  at  one 
time  prior  to  the  development 
of  the  cotton  industry  used  ex- 
tensively in  spinning  and  weav- 
ing on  the  Continent  of  Eu- 
rope, the  cloth  made  being 
known  as  grass-cloth,  the  name 
now  given  to  the  product  of  the 
China-grass,  or  ramie.  The 
fibre  when  cleansed  is  soft,  of 
good  length  and  strength,  and 
quite  lustrous  and  white.  The 
bast  fibres  of  the  linden  (Tilia 
Europcea)  and  of  the  paper- 
mulberry  -  tree  (Broussonetia 
papyrifera)  are  also  used,  the 
former  for  the  manufacture  of 
mats  in  Russia  and  the  latter 
by  the  paper-makers  of  China 
and  Japan. 

New  Zealand  Flax  is  a  fibre 

obtained  from  the  leaves  of  Phormium  tenax,  which  acquires  a  length 
of  one  to  two  metres.  The  fibre  as  prepared  by  hand-scraping,  the 
method  of  the  native  Maoris,  is  soft,  white,  and  of  silky  lustre ;  as  pre- 
pared by  machinery  it  is  distinctly  inferior  in  character.  Its  chief 
value  is  for  rope-making  and  for  coarse  textiles.  The  rope  made  from 
this  fibre  is,  however,  weakened  when  wet  by  sea-water,  and  therefore 
must  be  kept  well  oiled. 

Pineapple  Fibre. — The  leaves  of  the  several  varieties  of  Bromelia 
yield  a  fine,  nearly  colorless,  fibre,  which  is  worked,  especially  in  Brazil, 
for  the  manufacture  of  the  so-called  "silk-grass." 

Esparto. — This  is  a  grass,  cultivated  especially  in  North  Africa  and 
Spain,  where  ropes  and  cordage  are  made  from  it.  Its  chief  use,  how- 
ever, is  in  connection  with  paper-making.  (See  p.  313.) 

Cocoa-nut  Fibre  (Coir}. — The  coarse  fibrous  covering  of  the  nut  of 
the  coco  palm  is  largely  used  for  brooms,  brushes,  matting,  and  coarse 


China-grass  ( 


310 


VEGETABLE  TEXTILE  FIBRES. 


carpeting.    The  fibre  is  coarse,  stiff,  very  elastic,  round,  and  smooth  like 
hair.    It  also  has  great  tenacity,  and  is  well  adapted  for  cordage. 

The  classification  of  the  vegetable  fibres  just  enumerated  has  already 
been  made  upon  the  basis  of  the  iodine  and  sulphuric  acid  reaction 
according  to  Vetillart.  Two  groups  were  thus  established,  the  one  com- 
posed essentially  of  unaltered  cellulose  and  the  other  of  lignified  cellu- 
lose bastose.  Other  reactions  of  these  two  classes  of  materials  are  given 
in  the  accompanying  table  from  0.  Witt :  * 


Reagent. 

Cellulose. 

Bastose  (compound  of  cellulose  with 
lignin). 

Iodine  and  sulphuric  acid. 
Sulphate    of   aniline    with 
free  sulphuric  acid. 
Basic  aniline  dyes. 
Weak  oxidizing  agents. 
Ammoniacal  cupric  oxide. 

Produces  blue  color. 
Indifferent. 

Indifferent. 
Indifferent. 
Immediate  solution. 

Produces  a  yellow  or  brown  color. 
Colors  deep  yellow. 

Produces  fast  colors. 
Rapid  disintegration. 
Swelling  up,  blue  color,  and  slow 
solution. 

To  distinguish  the  several  more  important  vegetable  fibres  from  each 
other  when  admixed,  a  number  of  chemical  and  physical  tests  have  been 
proposed  in  addition  to  the  microscopical  study  of  the  structural  dif- 
ferences already  mentioned  under  the  individual  fibres. 

Thus,  according  to  Kindt's  test,  the  presence  of  cotton  fibre  in  linen 
goods  can  be  distinguished,  after  first  removing  the  size  or  dressing  by 
thorough  boiling  with  distilled  water  and  drying  again,  by  dipping  them 
from  one-half  to  two  minutes,  according  to  the  texture  of  the  goods,  in 
concentrated  sulphuric  acid.  They  are  then  well  washed  with  water, 
rubbed,  dipped  for  a  moment  in  ammonia-water,  and  dried.  The  cotton 
fibre  is  either  dissolved  or  gelatinized  and  removed  by  the  rubbing,  while 
the  linen  fibre  remains  unchanged  or  but  slightly  attacked.  By  counting 
the  flax  fibres  remaining  for  a  given  superficial  area  the  relative  pro- 
portion of  cotton  admixture  can  be  determined. 

The  different  effect  of  strong  caustic  potash  solution  upon  cotton  and 
linen  fibres  is  also  taken  as  decisive  at  times,  although  the  difference  is 
not  so  marked.  Both  kinds  of  fibres  shrink  in  size,  the  cotton  fibres 
remain  whitish  or  grayish  yellow,  while  the  linen  fibres  are  colored  deep 
yellow  or  orange. 

A  very  characteristic  test  is  that  given  by  Boettger.  A  piece  of  the 
mixed  goods  frayed  out  in  three  sides  is  first  dipped  in  a  one  per  cent, 
solution  of  fuchsine,  then  taken  out,  washed  in  running  water  until  this 
runs  off  clear,  and  dipped  in  ammonia-water  for  from  one  to  three 
minutes.  The  cotton  fibre  is  quickly  decolorized,  while  the  linen  fibre 
remains  bright  rose-red  in  color.  A  test  easily  applied  and  satisfactory 
is  the  oil  test,  but  it  is  only  applicable  to  white  goods  which  are  free 
from  size.  The  well-dried  sample  is  dipped  into  olive  oil,  and  then  well 
pressed.  The  linen  fibres  become  translucent  from  the  capillary  action 
upon  the  oil,  while  the  cotton  fibres  remain  white  and  dull  in  appearance. 

*  Chem.  Technologie  der  Gespinnstfasern,  p.  111. 


PAPER-MAKING.  311 

An  alcoholic  cochineal  solution  (one  part  of  powdered  dyestuff  di- 
gested with  twenty  parts  of  alcohol  of  .847  specific  gravity  for  twenty- 
four  hours)  is  also  recommended  by  Bolley.  Cotton  fibres  take  a  clear 
red  color  in  this  solution,  while  linen  fibres  are  colored  violet. 

A  special  test  to  distinguish  the  fibre  of  the  Phormium  tenax  (New 
Zealand  flax)  from  linen  or  hemp  is  given  by  Vincent.  It  is  in  the  use 
of  concentrated  nitric  acid,  which  colors  the  New  Zealand  flax  distinctly 
red,  but  does  not  change  the  other  fibres  mentioned.  (For  tests  to  dis- 
tinguish the  vegetable  fibres  as  a  class  from  the  animal  fibres,  see  p.  302.) 

The  use  of  the  microscope,  however,  is  much  the  most  reliable  means 
of  distinguishing  the  several  fibres  when  occurring  in  admixtures,  as  the 
structural  characters  are  sufficiently  distinct  to  allow  of  easy  recognition 
to  those  possessed  of  some  practice. 

INDUSTRIES  BASED  UPON  THE  UTILIZATION  OF 
VEGETABLE  FIBRES. 

The  great  utilization  of  these  fibres  is  of  course  in  the  manufacture  of 
textile  fabrics  of  all  grades.  Having  described  the  fibres  which  consti- 
tute the  raw  materials  of  these  industries,  we  shall  pass  the  mechanical 
side  of  their  treatment  and  shall  note  the  chemical  processes  of  bleach- 
ing, dyeing,  and  color-printing  in  a  later  section  of  the  work  (see  p.  522), 
after  the  preparation  of  natural  and  artificial  dye-colors  has  been  de- 
scribed. Other  industries  based  upon  utilization  of  some  one  or  more  of 
the  vegetable  fibres  are  Paper-making,  Pyroxylin  and  Gun-cotton,  Col- 
lodion, Celluloid,  and  most  recent  Artificial  Silk. 

A.   PAPER-MAKING. 
I.  Raw  Materials. 

1.  RAGS. — The  first  in  order  of  use  for  paper-making  and  still  the 
most  important  raw  materials  for  the  finer  grades  of  paper  are  linen 
and  cotton  rags.  As  the  cellulose  of  these  rags  has  already  undergone 
a  process  of  purifying  from  the  coloring  and  incrusting  matter  with 
which  it  was  first  associated  in  nature  in  its  preparation  for  manu- 
facture into  textile  fabrics,  it  is  well  adapted  for  use  in  paper-making, 
the  basis  of  which  is  also  a  cellulose  fibre.  Of  course,  the  rags  may  be 
of  all  grades  of  cleanliness.  They  may  be  cuttings  obtained  in  the  course 
of  manufacture  of  garments,  and  being  unworn  may  be  relatively  clean, 
or  they  may  be  fragments  of  cast-off  wearing  apparel  gathered  from 
waste-heaps  and  reeking  with  filth.  Indeed,  so  great  is  the  demand  for 
paper-making  stock  that  rags  are  gathered  from  Japan,  Egypt,  and  all 
parts  of  the  world,  and  the  bales  generally  require  careful  disinfection 
before  they  can  be  used.  They  may  contain  sizing  and  China  clay  and 
other  loading  materials,  or  they  may  be  colored  with  various  dyes  and 
metallic  salts.  Rags  considered  as  paper-making  stock  must  therefore  be 
assorted,  and  for  trade  purposes  they  are  divided  into  a  large  number 
of  grades  or  classes  distinguished  by  different  letters. 


312  VEGETABLE  TEXTILE  FIBRES. 

Linen  rags  are  distinctly  superior  for  paper-making  to  cotton  rags,  as 
they  make  a  stronger  and  more  durable  paper. 

2.  WOOD  FIBRE. — Two  varieties  of  pulp  for  paper-making  may  be 
obtained  from  wood, — viz.,  mechanically  and  chemically  prepared  pulp. 
Of  these,  the  mechanical  wood-pulp  obtained  by  shredding  the  wood 
serves  for  the  inferior  grades  of  paper  only,  as  its  fibres  are  too  short 
and  do  not  "felt"  or  interlace  sufficiently.  It  can  therefore  be  used 
only  as  a  filling  material.  Moreover,  the  resin  present  resists  strongly 
the  action  of  bleaching  agents,  and  the  paper  becomes  yellowish  after 
a  time.  This  mechanical  wood-pulp  is  known  to  the  trade  as  "ground 
wood"  and  it  is  obtained  by  forcing  the  barked  timber  cut  in  short 
lengths  against  rapidly  revolving  stones  or  grinders,  keeping  a  steady 
stream  of  water  in  contact  with  it  to  prevent  the  development  of  heat. 
This  fibre,  although,  as  said,  very  short,  is  used  in  enormous  quantities 
to  "fill  in"  in  the  manufacture  of  newspapers.  No  attempt  is  made  to 
bleach  it  before  making  paper,  it  being  merely  necessary  to  incorporate 
in  the  stock  sufficient  coloring  matter  to  overcome  the  yellowish  tinge 
which  otherwise  would  be  evident.  On  the  other  hand,  what  is  termed 
chemical  wood-pulp  has  met  with  great  favor  as  a  very  pure  and  easily 
obtainable  form  of  cellulose.  Chemical  pulp  is  made  by  three  distinct 
processes,  known  to  the  trade  as  the  sulphite,  soda,  and  sulphate  proc- 
esses. In  all  of  these  cases  the  timber  is  thoroughly  denuded  of  bark 
and  is  then  split  and  put  through  a  "hog"  or  chipper  which  produces 
short,  coarse  heavy  chips  of  about  a  half-cubic  inch  in  volume.  These 
are  screened  to  obtain  a  fair  degree  of  uniformity  and  separate  the  dust. 

In  the  sulphite  process,  there  are  two  methods  of  cooking,  known  as 
the  "quick  cook"  and  the  "slow  cook"  or  Mitscherlich  method.  The 
former  is  now  more  extensively  used  by  large  manufacturers  of  news- 
paper and  by  book  paper  manufacturers  to  obtain  their  raw  sulphite 
stock.  The  cooking  liquor  is  made  from  a  dolomitic  milk  of  lime  satu- 
rated with  sulphur  dioxide,  thus  forming  a  mixture  of  magnesium  and 
calcium  bisulphite;  or  by  another  method  high  wooden  towers  are  kept 
packed  with  lime-stone  while  water  is  allowed  to  pass  down  over  the 
stone  against  a  counter  current  of  sulphur  dioxide  which  displaces  the 
carbon  dioxide  in  the  limestone.  The  digestors  in  most  common  use 
are  about  forty  feet  high,  vertical,  with  conical  bottom,,  and  of  boiler 
steel  lined  with  rough  or  glazed  firebrick  set  in  an  alkaline  silicate 
cement.  The  "cook"  lasts  six  to  eight  hours,  during  which  time  a 
steam  pressure  of  about  120  pounds  is  maintained,  while  the  excess  of 
sulphur  dioxide  developing  is  frequently  allowed  to  pass  off  through 
relief  pipes.  The  pulp  when  "blown"  from  the  digester  is  washed  and 
if  for  book  or  writing  paper  is  bleached  with  chloride  of  lime,  or  if  for 
news,  wrapping  or  bag  paper  is  allowed  to  go  to  the  beating  engines 
unbleached. 

In  the  case  of  the  "slow  cook"  or  Mitscherlich  process,  a  horizontal 
cylindrical  digestor  is  used  having  the  same  kind  of  lining  as  above 
described,  but  in  which  the  heating  is  indirect  by  leaden  steam  coils 
placed  longitudinally  on  the  bottom  inside  the  digestor.  This  "cook" 


PAPER-MAKING.  313 

lasts  about  forty  hours  under  a  comparatively  low  pressure.  Although 
the  resulting  material  has  had  the  lignin  dissolved  from  it,  it  retains 
the  original  form  of  the  uncooked  chips  and  though  soft  must  be  ground 
before  beating.  Cross  and  Bevan  explain  the  efficacy  of  the  bisulphite 
processes  by  saying,  "The  chief  agency  is  the  hydrolytic  action  of  sul- 
phurous acid,  aided  by  the  conditions  of  high  temperature  and  pressure ; 
and  the  subsidiary  agencies  are,  (1)  the  prevention  of  oxidation;  (2)  the 
removal  from  the  sphere  of  action  of  the  soluble  products  of  resolution 
in  combination  with  the  sulphite  as  a  double  compound,  for  it  is  to  the 
class  of  aldehydes  that  we  have  shown  that  the  non-cellulosic  constitu- 
ents of  wood  belong;  and  (3)  the  removal  of  a  portion  of  the  constituents 
in  combination  with  the  base, — i.e.,  with  expulsion  of  sulphurous  acid." 

At  the  present  writing,  the  large  consumption  and  rapidly  dimin- 
ishing supply  of  timber  adapted  to  the  sulphite  process  will  cause  a 
search  for  new  fibres  and  an  abandonment  of  the  sulphite  process  in 
favor  of  the  other  chemical  processes  of  treatment. 

The  soda  process  is  used  for  the  working  of  a  variety  of  woods  such 
as  different  kinds  of  long-leaf  pine,  spruce,  hemlock,  poplar,  bass,  etc. 
The  cooking  of  the  wood  is  comparatively  simple.  A  vertical  clyindrical 
welded  digester  is  used  without  any  lining.  The  cooking  liquor  is 
generally  a  caustic  soda  solution  testing  about  12°  B.  The  time  of  di- 
gestion is  the  same  as  in  the  "quick  cook"  sulphite  process.  The  soda 
takes  up  the  ligneous  and  resinous  portion  of  the  wood,  and,  when  sepa- 
rated from  the  pulp,  is  evaporated,  incinerated,  and  recausticized,  with  a 
loss  of  ten  to  fifteen  per  cent,  in  recovery,  for  cooking  purposes.  In  this 
country,  a  large  proportion  of  the  soda  pulp  mills  use  poplar,  spruce, 
and  hemlock  for  the  production  of  a  fine  grade  of  pulp  for  book  paper. 
Others,  using  the  long-leaf  pine,  produce  a  long,  coarse  fibre  for  wrap- 
ping paper. 

The  sulphate  process,  in  large  use  in  Sweden  and  Norway  and  to  a 
small  but  increasing  extent  in  the  United  States,  produces  what  is  known 
as  a  "kraft"  pulp,  which  as  the  name  denotes,  has  an  extremely  strong 
fibre  and  makes  excellent  wrapping  paper.  To  obtain  this,  long-leaf 
pine  is  digested  in  soda  digestors,  and  the  process  corresponds  with  the 
soda  process  except  that  before  the  incineration  of  the  concentrated 
spent  soda  or  "black  liquor"  sulphate  of  soda  is  introduced,  which  in 
the  incineration  causes  the  formation  of  a  certain  amount  of  sodium 
sulphide  from  the  action  of  the  carbon  on  the  sulphate.  This  mixture 
of  the  caustic  soda  and  sodium  sulphide  in  cooking  has  the  proper  influ- 
ence on  the  chemical  changes  taking  place  and  produces  long  strong  fibre. 

3.  ESPARTO. — This  grass,  mentioned  under  the  vegetable  fibres   (see 
p.  309),  is  of  great  importance  as  a  paper-making  material,  particularly 
in  England.     The  Spanish  variety,  according  to  Hugo  Miiller,  contains 
48.25  per  cent,  and  the  African  variety  45.80  per  cent,  of  cellulose,  but 
the  yield  of  bleached  fibre  obtained  in  practice  probably  does  not  much 
exceed  forty  per  cent.     The  fibre  is  tough  and  it  makes  an  excellent 
paper,  whether  used  singly  or  in  admixture  with  other  materials. 

4.  STRAW. — As  a  material  for  admixing  with  other  fibres,   straw- 


314  VEGETABLE  TEXTILE  FIBRES. 

pulp  is  largely  used.  The  varieties  of  straw  so  utilized  are  oat,  wheat, 
rye,  and  barley.  Of  these,  rye  is  the  most  suitable  on  account  of  its 
yielding  the  largest  amount  of  fibre,  and  next  in  value  is  wheat.  The 
amount  of  cellulose  in  winter  rye  is  given  by  Hugo  Miiller  as  47.69  per 
cent,  and  in  winter  wheat  as  46.60  per  cent.,  but  probably  not  more  than 
thirty-five  per  cent,  is  actually  obtained  as  pulp,  much  being  lost  in  the 
treatment  on  account  of  the  loose  aggregation  of  the  cellular  tissue. 
Straw  contains  more  silica  than  Esparto,  and  hence  requires  more  soda 
in  the  after-treatment  to  free  the  cellulose  and  adapt  it  for  use. 

5.  JUTE. — The  "butts"  or  "cuttings"  rejected  by  the  textile  manu- 
facturer are  largely  used  in  the  manufacture  of  the  common  grades  of 
paper.     It  possesses  a  large  percentage  of  cellulose  (63.76  per  cent,  in 
the  best  fibre  and  60.89  per  cent,  in  the  "butts"),  but  it  cannot  be 
economically  bleached  to  a  white  color. 

6.  MANILA  HEMP. — This  is  very  like  jute  in  its  adaptability  for  cheap 
and  colored  papers,  and  as  the  fibre  is  a  lignified  cellulose  it  requires 
considerable  boiling  with  soda  to  prepare  it  for  use. 

7.  PAPER-MULBERRY. — In  China  and  Japan,  where  the  paper-makers 
excel  the  best  European  workmen  in  the  making  of  some  delicate  but 
strong  papers,  the  material  chiefly  used  is  the  inner  bark  of  the  paper- 
mulberry-tree    (Broussonetia  papyrifera},  the  leaves  of  which  can  be 
used  in  feeding  silk-worms.     The  strength  of  this  paper  is  due  to  the 
fact  that  in  making  the  pulp  the  long  bast-cells  are  not  broken  and  torn 
as  in  European  pulping-machines,  but  merely  softened  and  separated  by 
beating.     In  taking  up  the  pulp  in  the  mould  the  cells  are  made  to  lie 
in  one  direction,  and  the  paper  may  be  strengthened  by  taking  one  or 
more  dips  in  which  the  cells  are  made  to  lie  in  other  directions.     Some 
gum  is  added  to  make  the  cells  of  the  pulp  adhere. 

II.  Processes  of  Treatment. 

1.  MECHANICAL  PREPARATION  OF  THE  PAPER-MAKING  MATERIAL. — 
This  differs,  of  course,  according  as  the  raw  material  is  composed  of  rags 
or  other  cellulose-containing  substance.  "With  rags,  a  preliminary  sort- 
ing always  takes  place,  more  or  less  complete  according  to  the  make-up 
of  the  bales.  Numerous  commercial  designations  are  in  use  for  these 
different  grades  so  obtained.  We  need  only  speak  of  white  linen,  blue 
or  gray  linen,  white  cotton,  colored  linen  or  cotton,  sacking,  half  wool, 
etc.  They  are  then  cut  into  coarse  fragments  by  hand,  being  passed 
rapidly  over  broad  knives  fixed  at  a  set  angle  in  tables,  and  all  buttons 
and  hard  substances  removed.  A  thorough  dusting  or  "thrashing"  is 
now  necessary  to  remove  the  dust  and  detachable  dirt.  This  is  effected 
in  large  wooden  boxes  with  revolving  arms.  A  more  thorough  cutting 
now  ensues  with  the  aid  of  revolving  knives,  followed  in  most  cases  by  a 
final  and  thorough  dusting,  so  as  to  eliminate  as"  much  dirt  as  possible 
and  save  in  the  amount  of  boiling  necessary  as  the  next  operation. 

With  Esparto  a  mechanical  sorting  or  "picking"  is  also  the  first 
operation.  The  grass  is  spread  out  on  tables  and  the  weeds,  root-ends, 


PAPER-MAKING. 


315 


etc.,  carefully  removed,  as  these  would  be  difficult  to  boil  and  bleach  and 
would  give  rise  to  dark-colored  specks  in  the  finished  paper  known  as 
"sheave."  Machines  for  this  cleansing  of  the  Esparto  are  also  used 
quite  largely. 

The  preparation  of  mechanical  and  chemical  wood-pulp  has  already 

been  referred  to. 

FIG.  83. 


2.  BOILING. — The  boiling  of  the  rags  with  caustic  soda,  caustic  lime, 
or  a  mixture  of  soda  ash  and  lime,  which  is  the  next  operation,  is 
designed  to  free  them  from  grease,  dirt,  and  coloring  matter.  This  may 
be  done  either  in  rotating  spherical  or  cylindrical  boilers  or  in  the 
so-called  "vomiting"  boilers  described  later.  The  boilers  are  often  large 
enough  to  take  two  tons  of  rags  at  a  charge.  The  amount  of  alkali 
usually  ranges  from  five  to  ten  per  cent,  on  the  weight  of  the  rags. 
Soda  is  preferred  by  many  paper-makers  to  lime  on  account  of  the 
greater  solubility  of  the  compounds  it  forms,  although  both  are  in  gen- 
eral use.  The  time  of  boiling  varies  from  two  to  six  hours,  according  to 


316 


VEGETABLE  TEXTILE  FIBRES. 


FIG.  84. 


the  quality  of  rags,  the  alkali  employed,  and  the  pressure.     The  use  of 

high  pressure  is  to  be  avoided  as  far  as  possible,  as  it  may  result  in 

fixing  the  dirt  and  coloring 
matter  instead  of  dissolving 
them.  A  pressure  of  from  three 
to  four  atmospheres  is  com- 
monly employed.  After  the 
pressure  has  been  allowed  to 
fall,  the  liquor  collected  at  the 
bottom  of  the  boiler  is  drawn  off 
and  the  water  run  in  to  give  the 
rags  a  slight  preliminary  wash- 
ing. The  charge  is  then  drawn 
off. 

In  the  case  of  Esparto,  the 
"vomiting"  boiler  or  other 
form  of  apparatus  for  keeping 
up  a  continuous  circulation  of 
the  liquor  is  used.  A  form  of 
boiler  in  which  this  circulation 
is  kept  up  by  the  use  of  a  steam 
injector  is  shown  in  Fig.  83. 
The  grass  is  put  in  through  the 
man-hole  C  and  rests  upon  the 
false  bottom  B.  Circulation  is 
set  up  by  the  steam  from  the 
pipe  D  passing  through  the  in- 
jector E  and  drawing  the 
liquor  through  the  small  pipe  r. 
In  order  that  this  circulation 
may  proceed  uniformly,  it  is 
necessary  that  the  steam  shall 
enter  at  a  pressure  one  atmos- 
phere higher  than  the  pressure 
existing  in  the  boiler.  A  mano- 
meter, M,  shows  the  pressure, 
and  a  safety-valve,  V,  allows-  of 
*  the  adjustment  of  the  necessary 
conditions.  The  contents  of  the 
boiler  are  discharged  through  s 
at  the  end  of  the  operation.  The 
quantity  of  soda  necessary  de- 
pends upon  the  nature  of  the 
grass,  Spanish  requiring  less 
than  African,  and  the  pressure 

employed  varies  from  five  to  forty-five  pounds  per  square  inch. 

3.  WASHING. — This  operation,  which  must  be  a  thorough  one,  takes 

place  in  a  washer  or  "breaker."     The  name  "hollander"  is  very  gen- 


PAPER-MAKING.  317 

erally  given  to  this  machine  as  well  as  to  the  similar  one  in  which  the 
beating  or  mixing  is  done.  The  hollander  is  an  oval  iron  tube,  from  ten 
to  twenty  feet  long,  four  to  six  broad,  and  about  three  feet  high,  divided 
for  two-thirds  or  more  of  its  length  by  an  upright  partition  known  as 
the  "mid-feather."  The  details  of  its  construction  may  be  seen  from 
Figs.  84  and  85.  The  roll  A  carries  upon  its  circumference  a  number 
of  steel  knives  and  revolves  on  one  side  of  the  "mid-feather,"  or  longi- 
tudinal division  Q  Q  (Fig.  85).  The  floor  on  this  side  is  raised  in  such  a 
way  as  to  bring  the  pulp  well  under  the  roll,  as  shown  by  the  line  J  0  K 
(Fig.  84).  Immediately  under  the  roll  is  the  "bed-plate,"  shown  at  0, 
and  provided  with  knives  similar  to  those  in  the  roll  A,  but  set  with 
their  edges  in  the  opposite  direction.  The  distance  between  the  roll  and 
the  bed-plate  can  be  varied  at  will  by  means  of  the  hand-wheel  h  and 
the  mechanism  shown  at  k  and  i  (Fig.  85).  After  passing  between  the 
roll  and  the  bed-plate,  the  pulp  flows  down  the  "back-fall"  K  K,  and 
finds  its  way  around  to  the  other  side  of  the  mid-feather.  On  the  in- 
clined part  of  the  floor  and  immediately  in  front  of  the  bed-plate  a  small 
depression  is  made  at  E,  covered  with  an  iron  grating,  for  the  purpose 
of  catching  buttons,  small  pieces  of  stone,  and  other  foreign  substances 
that  may  have  found  their  way  into  the  rags  or  other  paper  stock.  The 
dirty  water  from  the  rags  is  removed  by  the  ' '  drum- washers "  R  R.  The 
ends  of  the  drums  are  of  wood,  and  the  circumference  is  covered  with 
fine  copper  or  brass  wire-cloth.  The  wash-water  passes  through  the  wire- 
cloth  into  the  compartment  shown  in  R,  and  passing  towards  the  nar- 
rower end  of  the  inner  conical  tub,  flows  out  through  the  side  of  the  drum 
into  a  trough  placed  to  receive  it. 

In  washing  the  rags  in  this  machine,  the  tub  is  partly  filled  with 
water,  the  rags  from  the  boiler  dumped  in,  and  the  operation  begun. 
The  action  of  the  roll  thoroughly  mixes  pulp  and  water  and  sweeps  the 
rags  up  the  incline  and  over  the  back-fall  K.  The  dirty  water  then 
passes  away  through  the  drum-washer,  the  supply  of  pure  water  being 
so  regulated  as  to  keep  the  level  constant.  When  the  water  begins  to 
run  off  clear  the  supply  is  stopped,  the  washer  still  being  kept  in 
action.  As  the  level  falls,  the  drum  is  lowered  by  means  of  the  handle  h. 
When  sufficiently  drained,  the  pulp  is  discharged  through  the  valves 
C  C  in  the  bottom  of  the  washer.  It  is  now  ready  to  be  bleached.  This 
may  be  done  in  the  washer  itself  or  in  separate  engines  called  "potchers." 
If  done  in  the  washer,  a  solution  of  bleaehing-powder  is  run  in  after 
the  withdrawal  of  the  wash- water  and  the  action  of  the  roll  continued. 

Esparto  is  generally  washed  in  exactly  the  same  way  as  that  just 
described  for  rags,  but  in  some  mills  the  grass  is  washed  in  a  series 
of  connected  lixiviating  tanks  like  those  used  in  alkali-works.  Pure 
water  flows  in  at  one  end,  passes  through  fresh  lots  of  grass  in  succes- 
sion, and  issues  at  the  farther  end  highly  charged  with  the  soluble  prod- 
ucts of  the  grass.  The  washed  and  broken  pulp  now  goes  by  the  name 
of  "half-stuff." 

4.  BLEACHING. — This  is  done  with  the  aid  of  chlorine  or  a  solution 
of  calcium  or  sodium  hypochlorite.  The  use  of  chlorine  gas,  once  largely 
practised,  has  been  almost  entirely  superseded  by  the  hypochlorite  solu- 


318 


VEGETABLE  TEXTILE  FIBRES. 


PAPER-MAKING.  319 

tions,  as  chlorine  is  liable  to  form  difficultly  removable  compounds,  and 
it  also  tends  to  attack  and  weaken  the  fibre  of  the  pulp.  When  chlorine 
is  used,  2.5  to  5  kilos,  of  salt  are  taken  as  needed  for  100  kilos,  of  "half- 
stuff." 

The  solution  of  calcium  hypochlorite  must  be  used  perfectly  clear 
and  free  from  undissolved  hydroxide  or  carbonate.  A  solution  of  6° 
Twaddle,  which  contains  about  half  a  pound  of  bleaching-powder  to  the 
gallon,  is  commonly  used.  An  addition  of  hydrochloric  or  sulphuric 
acid  to  the  bleaching-liquor  is  sometimes  made,  but  this  must  be  done 
with  care  so  as  not  to  liberate  chlorine  instead  of  hypochlorous  acid. 
This  danger  from  free  chlorine  is  greater  when  highly  lignified  fibres, 
such  as  wood  or  jute,  are  used.  The  bleaching  is  often  effected  by  com- 
bining a  preliminary  treatment  in  the  "potcher"  or  washer  with  a  sub- 
sequent prolonged  steeping  in  tanks.  A  process  has  been  recently  pro- 
posed by  Professor  Lunge  involving  the  use  of  acetic  acid.  The  quan- 
tity required  is  very  small,  as  during  the  process  of  bleaching  it  becomes 
regenerated.  Any  free  lime  in  the  solution  is  first  nearly  neutralized 
with  a  cheaper  acid,  such  as  hydrochloric  or  sulphuric  acid,  followed 
by  the  addition  of  the  acetic  acid.  The  process  is  said  by  Cross  and 
Bevan  to  give  excellent  results  with  high-class  material,  such  as  the 
best  cotton  and  linen  rags,  but  is  not  to  be  recommended  for  materials 
like  straw  or  Esparto. 

A  process  invented  by  Thompson  is  also  said  to  be  very  effective  for 
the  bleaching  of  rags.  It  consists  in  saturating  the  materials  with  a 
weak  solution  of  bleaching-powder  and  then  exposing  them  to  the  action 
of  carbonic  acid  gas.  The  bleaching  action  is  thus  made  very  rapid 
and  effective. 

One  of  the  most  recent  innovations  in  bleaching  is  the  application  of 
electricity  in  this  connection.  The  earliest  process  that  attracted  much 
attention  was  that  of  M.  Ilermite.  It  is  thus  described  by  Cross  and 
Bevan:*  "This  process  is  based  upon  the  electrolysis  of  a  solution  of 
magnesium  chloride,  this  salt  having  been  found  to  give  the  most 
economical  results.  The  solution,  at  a  strength  of  about  2.5  per  cent,  of 
the  anhydrous  salt  (MgCl2),  is  electrolyzed  until  it  contains  the  equiva- 
lent of  about  three  grammes  of  chlorine  per  litre.  This  solution  is  then 
run  into  the  'potcher'  containing  the  pulp  to  be  bleached;  a  continuous 
stream  is  then  kept  up,  the  excess  being  removed  by  means  of  a  drum- 
washer.  This  excess,  which,  after  being  in  contact  with  the  pulp  in  the 
engine,  is  more  or  less  deprived  of  its  bleaching  properties,  is  then 
returned  to  the  electrolyzing-vat,  where  it  is  again  brought  up  to  normal 
strength.  It  is  claimed  that  the  bleaching  effect  is  much  stronger  than 
that  of  the  corresponding  amount  of  calcium  hypochlorite  solution.  More- 
over, the  bleaching  is  much  more  rapid  and  the  loss  of  weight  which  the 
substances  undergo  is  less  for  equal  degrees  of  whiteness  obtained." 
In  this  country  several  successful  electrolytic  bleaching  processes  have 
been  introduced  in  connection  with  the  paper  and  pulp  industry,  such 

*  Text-book  of  Paper-Making,  p.   115. 


320  VEGETABLE  TEXTILE  FIBRES. 

as  the  Carmichael  electrolytic  process  and  the  Whiting  electrolytic 
process,  both  extensively  used. 

The  removal  of  any  excess  of  chlorine  or  bleaching-liquor  must  now 
be  looked  to.  This  is  done  either  by  careful  washing  or  by  the  use  of 
an  ' '  antichlor. ' '  The  first  method  has  the  advantage  of  not  only  remov- 
ing the  bleach  but  also  of  the  chloride  of  calcium  which  has  been  formed 
from  it.  It,  however,  takes  some  time  and  consumes  a  large  amount  of 
water.  Much  more  general  is  the  use  of  an  "antichlor."  The  com- 
monest of  these  is  sodium  thiosulphate  (or  hyposulphite,  as  it  is  com- 
monly called).  This  is  ordinarily  decomposed  according  to  the  reaction 
2(Ca(C10)2)  -f  Na.,S208  -f  H20  =  2CaS04  -f  2HC1  +  2NaCl,  but  when 
the  solutions  are  very  dilute,  sodium  tetrathionate,  Na2S4O6,  and  caustic 
soda  and  lime  are  formed.  For  the  first  equation  two  hundred  and 
forty-eight  parts  of  commercial  thiosulphate  are  required  to  neutralize 
four  hundred  and  nine  parts  of  bleaching-powder  of  thirty- five  per  cent, 
available  chlorine  strength.  The  various  sulphites  are  also  in  use  as 
antichlors,  sodium  sulphite  being  the  most  important.  A  cheap  anti- 
chlor is  also  made  by  boiling  together  lime  and  sulphur,  the  resultant 
calcium  sulphide  solution  containing  a  mixture  of  calcium  thiosulphate 
and  calcium  pentasulphide.  This  last-mentioned  preparation  is,  how- 
ever, objectionable  on  account  of  the  free  sulphur  formed,  as  this  affects 
the  pulp  injuriously.  Whatever  antichlor  is  used,  an  excess  should  be 
avoided,  as  it  may  act  upon  the  color  or  size  added  subsequently.  The 
antichlor  should  therefore  be  added  in  successive  small  portions,  and 
any  hypochlorite  solution  still  remaining  be  tested  for  from  time  to 
time  with  iodide  of  starch  paper,  which  will  be  turned  blue  as  long  as 
hypochlorite  remains. 

5.  BEATING. — The  bleached  pulp,  or  "  half-stuff ,"  is  not  yet  in  con- 
dition for  making  an  even  paper,  as  the  fibre  has  not  been  sufficiently 
disintegrated.  This  is  now  effected  in  the  beating-engine,  which  is  a 
hollander  very  similar  to  the  breaker  already  illustrated,  except  that 
the  roll  carries  more  knives  and  it  is  usually  let  down  much  nearer  the 
bed-plate.  The  half-stuff  is  furnished  in  successive  portions  to  the  beater 
previously  partially  filled  with  water,  each  successive  portion  being 
allowed  to  mix  thoroughly  with  the  water  before  another  lot  is  added. 
This  is  continued  until  the  mass  is  so  thick  that  it  will  only  just  turn 
round  under  the  action  of  the  roll.  The  operation  of  beating  is  designed 
to  be  a  more  complete  breaking  or  tearing  apart  of  the  fibres  rather  than 
a  cutting,  as  this  latter  result  would  interfere  with  the  felting  of  the 
fibres  so  necessary  in  paper-making.  Cotton  and  linen  rags  naturally 
take  longer  than  most  other  paper-making  material,  taking  often  as 
much  as  ten  hours;  wood-pulp  requires  to  be  very  gently  and  slowly 
beaten,  so  that  it  requires  some  six  hours;  while  Esparto  is  sufficiently 
disintegrated  in  from  two  to  four  hours.  In  making  the  finer  grades  of 
paper,  the  roller  bars  or  knives  instead  of  being  made  of  steel  are  made 
of  bronze,  so  that  contamination  with  oxide  of  iron  is  avoided. 

Beaters  of  a  totally  different  form  of  construction  are  also  largely  in 
use.  Thus,  in  the  Jordan  beater  the  roll  is  in  the  shape  of  a  truncated 


PAPER-MAKING.  321 

cone,  fitted  with  knives  and  revolving  in  an  iron  box  of  corresponding 
shape,  and  also  fitted  with  knives  set  at  an  angle.  In  the  Kingsland 
engine  and  the  Gould  engine  a  circular  plate  furnished  with  knives 
revolves  against  one  or  more  stationary  plates  similarly  fitted,  somewhat 
after  the  manner  of  millstones.  The  half-stuff  is  even  more  thoroughly 
disintegrated  in  these  beaters  than  in  the  ordinary  forms. 

6.  LOADING,  SIZING,  COLORING,  ETC. — Except  in  the  very  finest  papers, 
some  mineral  loading  material  is  incorporated  with  the  pulp  when  in  the 
beater.    This  is,  of  course,  in  the  main  for  cheapening  purposes,  but  also 
serves  the  useful  purpose  of  filling  the  pores  of  the  paper  and  enabling 
it  to  take  a  better  surface  in  the  subsequent  operations  of  calendering. 
Such  loading  materials  are  China  clay,  or  kaolin,  sulphate  of  lime,  or 
"pearl  hardening,"  barium  sulphate,  precipitated  chalk,  bauxite,  pre- 
cipitated magnesia,  and  magnesium  silicate,  or  "agalite."    The  amount 
added  varies  from  two  or  three  per  cent,  to  twenty  per  cent.,  or  in  rare 
cases  even  more. 

All  papers  except  blotting-papers  have  also  to  be  sized.  This  is  for 
the  purpose  of  filling  the  pores  with  some  material  that  will,  to  some 
degree  at  least,  resist  the  action  of  water.  Thus,  all  writing-papers,  and 
in  general  printing-papers  also,  are  sized  to  prevent  the  ink  applied 
to  them  from  running.  This  is  done  either  by  what  is  termed  "engine- 
sizing" — that  is,  in  the  beating-engine  itself — or  by  "tub-sizing,"  when 
the  paper  as  it  goes  through  the  Fourdrinier  machine  (see  below)  passes 
through  a  tub  of  gelatine  size  and  takes  a  layer  of  the  same  on  either 
surface. 

In  "engine-sizing"  a  rosin  soap  is  first  added  to  the  pulp  in  the 
beater,  and  when  this  is  thoroughly  incorporated  a  solution  of  alum  is 
run  in,  forming,  as  it  has  been  generally  supposed,  a  resinate  of  alumina, 
which  is  water  resistant  when  dried.  Wurster  *  claims  to  have  shown, 
however,  that  the  sizing  in  this  case  is  not  due  to  the  formation  of  a 
resinate  of  alumina  but  to  a  separation  of  free  resin,  and  in  this  result 
he  has  been  supported  by  Conradin.f 

With  the  resin  soap  is  also  added  some  starch,  and  the  quantity  of 
mixed  rosin  and  starch  is  usually  from  three  to  four  pounds  to  the  one 
hundred  pounds  of  pulp. 

The  pulp  although  bleached  is  rarely  white  enough  to  produce  a 
clear  white  paper,  and  the  yellowish  tint  requires  to  be  neutralized  by 
the  addition  of  small  quantities  of  blue  and  pink  coloring  material. 
Ultramarine,  smalt,  and  aniline-blue  are  used  for  the  first  color,  and 
either  cochineal,  Brazil-wood,  or  aniline-red  for  the  second.  The  paper 
may  be  colored  throughout  any  desired  color  by  using  rags  previously 
dyed,  or  by  adding  to  the  bleached  pulp  in  the  beater  the  necessary  dyes 
or  pigments. 

7.  MANUFACTURE  OF  PAPER  FROM  THE  PULP. — We  have  to  consider 
here  two  different  products, — viz.,  hand-made  paper  and  machine-made 
paper.    The  former  is  made  by  taking  in  the  mould  upon  the  ' '  deckel, ' ' 
or  wire-cloth  frame,  just  sufficient  of  the  prepared  pulp  diluted  with 

*  Wagner's  Jahresbericht,    1878,   p.    1155.  flbid.,   1879,  p.   1106. 

21 


322  VEGETABLE  TEXTILE  FIBRES. 

water  to  make  a  sheet  of  paper.  As  the  water  drains  through  the  wire- 
cloth  and  leaves  the  fibres  spread  out  upon  the  surface,  the  felting 
operation  is  assisted  by  shaking  the  frame  gently  from  side  to  side. 
The  mould  with  the  sheet  of  paper  is  then  turned  over,  and  the  sheet 
thus  transferred  from  the  wire  to  a  piece  of  felt.  When  a  number  of 
sheets  have  been  thus  prepared,  they  are  piled  up  with  alternate  sheets 
of  felt  and  the  whole  subjected  to  strong  pressure  to  expel  water.  They 
are  then  sized  if  required  by  dipping  them  into  a  solution  of  gelatine, 
again  pressed,  and  hung  up  to  dry.  When  dry  they  are  calendered  or 
pressed  between  hot  metal  rolls. 

Machine-made  paper  is  made  on  what  is  universally  known  as  the 
Fourdrinier  machine,  of  which  an  improved  form,  as  manufactured  by 
the  Pusey  and  Jones  Company,  of  •  Wilmington,  Delaware,  is  shown  in 
Fig.  86.  We  cannot  here  describe  the  various  mechanical  details  of  this 
machine,  but  may  summarize  by  saying  that  it  consists  of  an  endless 
mould  of  wire-cloth  on  to  which  the  prepared  pulp  flows  from  the  ' '  stuff- 
chest"  through  a  "  regulating-box "  and  over  the  li  sand-table "  and  the 
"screen."  From  the  deckel  wire  it  now  passes  through  a  series  of  rolls, 
at  first  covered  with  felt  and  later  of  smooth  heated  metal  known  as  the 
"dandy-roll,"  the  "couch-rolls,"  the  "press-rolls,"  the  "  drying  cylin- 
ders," and,  finally,  the  "calenders."  The  action  of  the  machine  is  a 
continuous  one,  and  the  speed  of  the  Fourdrinier  is  from  sixty  to  two 
hundred  and  forty  feet  per  minute, — the  latter  for  cheap  newspaper, 
the  former  for  the  best  paper  requiring  the  most  care. 

What  is  known  as  "tub-sizing"  is  applied  to  many  machine-made 
papers  in  the  course  of  their  passage  through  the  Fourdrinier.  A 
filtered  solution  of  gelatine  is  used  to  which  about  twenty  per  cent,  of 
its  weight  of  alum  has  been  added.  A  certain  quantity  of  soap  is  also 
often  added,  a  white  soap  free  from  resin  being  used. 

Instead  of  the  Fourdrinier,  what  are  termed  cylinder-machines  are 
also  in  use,  in  which  a  large  drum  or  cylinder  covered  with  wire-cloth 
revolves  in  the  vat  containing  the  pulp.  As  it  revolves  the  fibres  attach 
themselves  to  the  wire  and  the  water  is  sucked  through  the  meshes  by 
a  partial  vacuum  within.  The  sheet  of  paper  thus  formed  is  taken  on 
to  an  endless  felt  passing  over  a  couch-roll,  which  revolves  in  contact 
with  the  hollow  drum,  and  thence  passes  to  a  large  drying  cylinder 
heated  by  steam.  Paper  made  on  such  a  machine  is  weaker,  however, 
than  that  made  on  the  Fourdrinier,  because  it  has  not  been  found  pos- 
sible to  give  the  shaking  motion  to  the  cylinder  necessary  to  produce  the 
felting  of  the  fibres. 

IE.  Products. 

The  products  are  almost  without  number,  and  vary  not  only  in  dif- 
ferent countries,  but  even  locally  from  time  to  time  as  different  mills 
change  their  production.  We  will  therefore  attempt  only  a  general 
classification  of  the  main  varieties. 

1.  BLOTTING-  AND  TISSUE-PAPER. — These  are  unsized  papers.  Blot- 
ting-paper is  a  mass  of  loosely-felted  fibres,  which,  however,  is  free  from 


PAPER-MAKING. 


323 


324  VEGETABLE  TEXTILE  FIBRES. 

any  loading  or  filling  material,  and  therefore  is  capable  of  easily  and 
quickly  taking  up  water  or  other  liquids.  It  may  be  white,  gray,  or 
colored  to  any  shade  by  the  addition  of  the  proper  dyes.  Tissue-papers, 
which  as  the  name  indicates  are  the  thinnest  of  all  papers,  are  made 
from  very  strong  fibres,  such  as  that  of  hemp-bagging  and  cotton  canvas, 
and  on  machines  somewhat  different  from  the  ordinary  Pourdrinier. 

2.  WRAPPING-PAPERS. — These    are    partially-sized    papers    of    coarse 
materials,  such  as  straw,  jute,  Manila  hemp,  common  rags,  etc.     They 
may  show  the  natural  color  of  the  materials  or  may  be  colored,  as  in  the 
case  of  the  blue  wrapping-paper  commonly  used  for  packing  sugar.     A 
more  strongly  sized  and  calendered  wrapping-paper  is  made  for  use  with 
linens  and  other  textile  goods. 

3.  PRINTING-PAPERS. — These  are  -white  papers,  generally  with  filling 
and  sizing  material,  although  some  special  grades  are  given  a  smooth 
surface  by  calendering  instead  of  sizing.     The  cheaper  grades  for  news- 
paper use  are  frequently  largely  adulterated  with  filling  material,  and 
mechanical  wood-pulp  is  also  largely  used  in  their  manufacture. 

4.  WRITING-PAPERS. — These  are  thoroughly-sized  papers,   for  which 
the  best  materials  are  generally  used,  linen  rags  alone  being  taken  for 
the  finer  grades. 

5.  CARDBOARD,  PASTEBOARD,  AND  PAPIER-MACHE. — Pasteboard  may  be 
made  by  pressing  a  number  of  sheets  of  freshly-formed  unsized  paper  in 
powerful  presses,  or  cementing  them  together  by  the  use  of  glue  or  other 
cementing  material,  and  then  pressing  the  mass  so  formed.     Cardboard 
is  made  direct  upon  machines  adapted  for  heavy  layers  of  pulp  and 
pressed  and  calendered  like  similar  grades  of  ordinary  paper.     Papier- 
mache  is  made  chiefly  from  old  paper  by  boiling  to  a  pulp  with  water, 
pressing,  mixing  with  glue  or  starch  paste,  and  then  pressing  in  moulds 
previously  oiled.    After  drying,  the  articles  are  soaked  with  linseed  oil 
and  then  dried  at  higher  temperature. 

PARCHMENT-PAPER. — If  a  pure  unsized  paper  be  dipped  in  sulphuric 
acid  of  60°  B.  a  portion  of  the  cellulose  is  changed  into  amyloid  (hydro- 
cellulose,  according  to  Girard),  which  forms  a  gelatinous  coating  over 
the  swollen  fibres  and  effects  in  some  degree  a  sizing  of  them.  The  paper 
is  made  hereby  translucent  and  parchment-like,  the  strength  is  increased 
from  three  to  fourfold,  and  the  specific  gravity  by  perhaps  forty  per 
cent.  For  the  manufacture  of  this  parchment-paper  the  long-fibred, 
unfilled  paper  is  to  be  chosen.  After  treatment  the  paper  is  quickly 
washed,  first  with  water,  then  with  weak  ammonia,  and  again  with  water. 

In  place  of  sulphuric  acid  we  have  the  treatment  with  ammoniacal 
cuprous  oxide  solution  or  zinc  chloride.  The  former  reagent  furnishes 
the  Willesden  ware,  which  always  retains  the  light  blue-green  color;  the 
latter  yields  the  valuable  product  known  as  indurated  or  hard  fibre. 
In  preparing  this  latter  material  the  paper,  which  is  either  unsized  or 
prepared  with  a  rosin  size  and  then  nearly  dried,  is  dipped  or  run  while 
in  the  roll  through  a  bath  of  zinc  chloride  of  about  65°  to  70°  B.  kept 
at  a  temperature  of  about  38°  C.  After  passing  through  the  zinc  chlo- 
ride bath,  the  paper  is  passed  over  hot  rolls  and  then  cooled  and  washed 
in  pure  water  to  remove  all  excess  of  zinc  chloride  or  rosin  size.  It  is 


PAPER-MAKING.  325 

then  dried  in  a  heated  room,  given  a  coating  of  paraffin  oil,  and  calen- 
dered. The  material  so  obtained  is  very  strong,  tough,  and  can  be 
washed. 

6.  SIDE-PRODUCTS. — Recovered  Soda. — The  alkaline  liquors  in  which 
rags,  esparto,  and  other  paper-making  material  have  been  boiled  were  at 
one  time  run  off  as  waste  products.  This  is  no  longer  done  in  properly 
conducted  mills,  as  the  alkali  used  can  be  recovered  in  the  form  of 
carbonate  by  evaporation  of  the  waste-liquor  and  ignition  of  the  residues, 
and  this  carbonate  can  then  be  causticized  and  fitted  for  renewed  use. 
The  soda  during  the  process  of  boiling  with  the  paper-making  materials 
takes  up  a  large  amount  of  non-cellulose  fibre  constituents,  such  as 
resin,  coloring  matter,  and  silica.  These  on  evaporation  and  ignition 
become  either  carbonate  or  silicate.  It  will  not  be  possible  for  us  here 
to  describe  the  forms  of  evaporators  in  use  for  this  soda  recovery.  One 
of  the  best-known  evaporators  is  that  of  Porion,  used  largely  in  Eng- 
land on  the  Continent.  For  a  description  of  this  and  other  forms, 
see  Cross  and  Bevan's  "Text-book  of  Paper-Making,"  p.  182.  In  this 
country  the  Swenson  form  of  evaporator  has  been  largely  used  for  the 
"black  liquor"  of  the  soda  pulp  works. 

The  recovered  soda  consists  essentially  of  carbonate  of  soda,  together 
with  a  certain  amount  of  silicate  of  soda  if  the  liquor  had  been  obtained 
by  boiling  straw  or  esparto.  The  causticizing  is  done  in  the  usual  way 
with  caustic  lime  and  the  clear  alkali  decanted  from  the  separated  cal- 
cium carbonate,  which  is  then  thoroughly  washed. 

IV.  Analytical  Tests  and  Methods. 

1.  DETERMINATION  OF  THE  NATURE  OF  THE  FIBRE. — This  may  be  done 
in  part,  if  not  wholly,  by  either  of  two  methods, — viz.,  by  the  aid  of  the 
microscope  or  by  the  use  of  chemical  tests  for  individuals  fibres.  The 
fibre  is  always  torn  or  cut  and  often  somewhat  attacked.  By  some  prac- 
tice, however,  it  is  possible  to  distinguish  between  cotton  and  linen  or 
to  identify  both  in  admixture.  Wood  and  straw  can  also  be  identified. 
In  making  these  tests,  it  is  best  to  take  strips  of  the  paper  in  question 
and  boil  them  in  succession  with  alcoholic  potash  solution,  with  water, 
with  two  per  cent,  hydrochloric  acid,  and  then  again  with  water.  If 
they  are  now  shaken  up  with  a  little  warm  water,  we  obtain  a  fine  magma 
of  fibres,  which  when  mixed  with  an  equal  volume  of  glycerine  is  well 
adapted  for  examination  under  the  microscope.  The  distinctive  char- 
acters of  some  of  the  chief  paper-making  materials  as  seen  under  the 
microscope  may  be  thus  summarized,  according  to  Cross  and  Bevan :  * 
Cotton, — flat,  ribbon-like  fibres,  frequently  twisted  upon  themselves. 
The  ends  generally  appear  laminated.  Linen, — cylindrical  fibres,  similar 
to  the  typical  bast  fibre.  The  ends  are  frequently  drawn  out  into  numer- 
ous fibrillse.  Esparto, — the  pulp  consists  of  a  complex  of  bast  fibres  and 
epidermal  cells.  The  most  characteristic  feature  of  esparto  pulp  is  the 
presence  of  a  number  of  fine  hairs  which  line  the  inner  surface  of  the 
leaf,  some  of  which  still  remain  after  the  boiling  and  washing  processes. 

*  Text-book  of  Paper-Making,  p.  199. 


326  VEGETABLE  TEXTILE  FIBRES. 

The  presence  of  these  hairs  may  be  taken  as  conclusive  evidence  of  the 
presence  of  esparto.  Straw, — this  closely  resembles  esparto  pulp  in 
microscopical  features,  except  that  the  hairs  are  absent.  On  the  other 
hand,  a  number  of  flat  oval  cells  are  always  present  in  paper  made  from 
straw.  Chemical  wood-pulp, — flat  ribbon-like  fibres,  showing  unbroken 
ends.  The  presence  of  pitted  vessels  is  eminently  characteristic  of  pulp 
prepared  from  pine-wood.  Mechanical  wood-pulp  may  be  recognized 
by  the  peculiar  configuration  of  the  torn  ends  of  the  fibres  and  from  the 
fact  that  the  fibres  are  rarely  separated,  but  generally  more  or  less 
agglomerated.  The  pitted  vessels  of  pine-wood  also  show,  and  usually 
more  distinctly  than  in  chemical  wood-pulp. 

The  chemical  reagent  most  useful  in  testing  paper-pulp  is  aniline 
sulphate.  With  most  of  the  fibres  which  consist  of  cellulose  simply  it 
gives  no  reaction.  Straw,  esparto,  and  mechanical  wood-pulp  can,  how- 
ever, be  identified  by  its  means.  Thus,  where  paper  containing  straw 
or  esparto  is  treated  for  some  time  with  a  boiling  one  per  cent,  solution 
Of  aniline  sulphate,  a  pink  color  is  produced.  Esparto  gives  the  reaction 
with  greater  intensity  than  straw.  Mechanical  wood-pulp  treated  with 
this  solution  develops  even  in  the  cold  a  deep-yellow  color.  According 
to  Bolley,*  the  moistening  of  paper  containing  mechanical  wood-pulp 
with  nitric  acid  will  give  the  same  result,  and  a  naphthylamine  salt 
produces  a  deeper  orange  color.  According  to  Wiesner,  phloroglucin 
is  also  a  delicate  reagent  for  wood  fibre  in  paper.  A  drop  of  dilute 
solution  of  phloroglucin  put  upon  the  paper  and  this  followed  by  mois- 
tening with  hydrochloric  acid  develops  an  intensely  red  color.  Fuch- 
sine  also  colors  wood  fibre  red,  but  has  no  effect  upon  paper  from  linen 
fibre  alone. 

M.  Wurster  in  "Journ.  de  Pharm.  et  Chemie"  has  extended  Wies- 
ner's  observation  on  phloroglucin  to  a  number  of  the  phenols,  finding 
them  as  a  class  to  serve  as  reagents  for  distinguishing  between  wood- 
pulp  and  other  cellulose.  The  results  are : 

Reagent.  Wood-pulp.  Cellulose  paper. 

Orcin     Dark  red.  No  color. 

Resorcin    Deep  green.  Violet. 

Pyrogallol     Blue-green  Violet. 

Phenol    Yellow-green.         Violet. 

Phloroglucin    Blue-violet.  No  color. 

According  to  Godeffroy  and  Coulon,  mechanical  wood-pulp  from 
pine-wood  possesses  the  property,  after  it  has  been  extracted  with  water, 
alcohol,  and  ether,  of  reducing  gold  solutions  on  boiling.  This  property 
is  not  possessed  by  wood-pulp  prepared  by  the  caustic  soda  or  sulphite 
processes,  after  similar  extraction  with  solvents,  nor  by  the  pulp  pre- 
pared from  linen  or  cotton  fibres.  This  property  depends  upon  the  fact 
that  in  mechanical  wood-pulp  ligno-cellulose  remains,  and  to  this  com- 
position is  due  the  reducing  power  upon  gold  solutions.  This  ligno- 
cellulose  is  destroyed  in  the  preparation  of  chemical  wood-pulp,  and  does 
not  exist  at  all  in  the  linen  or  cotton  fibre.  It  has  been  found  that  on 
the  average  one  hundred  parts  of  mechanical  wood-pulp,  extracted  with 

*  Handbuch   der   Technisch-Chem.   Untersuchungen,   Gte   Auf.,   p.    1006. 


GUN-COTTON,  PYROXYLINS,  ETC.  327 

solvents  and  dried  at  100°  C.,  will  reduce  fourteen  thousand  two  hundred 
and  eighty-five  grammes  of  gold.  It  is  thus  made  possible  by  weighing 
the  reduced  gold  to  estimate  the  amount  of  mechanical  wood  entering 
into  the  composition  of  the  paper.  For  details  of  the  analytical  method 
based  upon  this  gold  reaction,  see  Bolley's  "Handbuch  der  Technisch- 
Chem.  Unterschungen, "  6te  Auf.,  p.  1007. 

2.  DETERMINATION   OF   THE   NATURE   OF   LOADING   MATERIALS. — The 
total  amount  of  the  mineral  loading  material  is  determined  by  igniting  a 
weighed  quantity  of  the  paper  until  the  ash  is  white  or  grayish  and  then 
accurately  weighing  this.     The  ash  from  a  paper  containing  the  China 
clay  is  insoluble  in  boiling  dilute  hydrochloric  acid;  that  from  paper 
containing  calcium  sulphate  is  soluble,  and  deposits  on  standing  needle- 
shaped  crystals  of  gypsum  easily  recognizable  by  chemical  tests. 

3.  DETERMINATION  AS  TO  NATURE  OF  THE  SIZING  MATERIALS. — The 
iodine  test  serves  to  indicate  the  use  of  starch  in  the  size,  as  it  produces 
the  well-known  blue  color.     Extraction  of  the  paper  with  alcohol  con- 
taining a  few  drops  of  acetic  acid  serves  to  show  the  resin  used  in  the 
size.     The  alcohol,  after  cooling,  is  poured  into  four  or  five  times  its 
bulk  of  water,  when  the  resin  separates,  producing  cloudiness  or  tur- 
bidity.   Or,  after  extraction,  the  alcohol  is  evaporated,  leaving  the  resin 
capable  of  being  identified  by  its  properties.     Notable  quantities  of 
alumina  in  the  ash  also  point  to  the  use  of  resinate  of  alumina  as  sizing 
material.    According  to  Wurster,  if  between  two  sheets  of  paper  which 
have  been  sized  with  resin  is  pressed  paper  moistened  with  tetramethyl- 
paraphenylen-diamine  solution,  a  bluish-violet  color  is  produced,  while 
paper  free  from  resin  is  not  affected.    Boiling  of  the  paper  sample  with 
distilled  water,  filtering,  and  adding  a  few  drops  of  tannic  acid  solution 
will  serve  to  show  the  presence  of  gelatine  sizing.     If  present,  a  white 
curdy  precipitate  is  formed  on  the  addition  of  the  tannic  acid. 

4.  DETERMINATION  OF  THE  NATURE  OF  THE  COLORING  MATERIAL. — 
In  deciding  as  to  the  presence  of  coloring  matter,  we  must  bear  in  mind 
the  reactions  of  the  commoner  pigments  used.    Ultramarine  is  destroyed 
and  decolorized  on  addition  of  acids;  Prussian  blue  is  decolorized  by 
heating  with  alkalies;  indigo  is  decomposed  by  heating  with  chlorine 
or  nitric  acid;  smalt  withstands  the  action  of  both  acids  and  alkalies 
and  remains  in  the  ash  as  a  blue  glass ;  the  aniline  colors  are  capable  of 
extraction  with  alcohol  as  solvent. 

B.  GUN-COTTON,  PYROXYLINE,  COLLODION  AND 
CELLULOID. 

I.  Raw  Materials. 

The  basis  of  these  preparations  is  the  class  of  nitrates  formed  from 
cellulose  by  the  action  of  nitric  acid,  either  taken  singly  or  admixed  with 
strong  sulphuric  acid,  or  as  developed  by  the  action  of  sulphuric  acid 
upon  a  nitrate.  Using  the  doubled  formula  C12H20010,  we  may  note  the 
following  five  stages  of  nitration: 

Hexanitrate,  C12H14O4(N03)6  (trinitro-cellulose,  C6H7(N02)305,  of 
other  writers),  is  the  true  gun-cotton.  It  is  formed  by  the  action  of  a 


328  VEGETABLE  TEXTILE  FIBRES. 

mixture  of  the  strongest  nitric  acid  (specific  gravity  1.52)  with  two  or 
three  parts  of  concentrated  sulphuric  acid,  in  which  the  cotton  is  im- 
mersed for  twenty-four  hours  at  a  temperature  not  exceeding  10°  C. 
(56°  F.).  The  hexanitrate  so  prepared  is  insoluble  in  alcohol,  ether, 
or  a  mixture  of  both,  in  glacial  acetic  acid,  or  in  methyl  alcohol.  Ace- 
tone dissolves  it  very  slowly.  According  to  Eder,  mixtures  of  nitre 
and  sulphuric  acid  do  not  give  this  nitrate.  It  contains  14.14  per  cent. 
nitrogen. 

Pentanitrate,  C12H15O5(N03)5.  It  is  difficult,  if  not  impossible,  to 
prepare  this  nitrate  in  a  state  of  purity  by  the  direct  action  of  the  acid 
upon  cellulose.  The  best  method  (that  of  Eder)  is  to  dissolve  gun-cotton 
(hexanitrate)  in  nitric  acid  at  about  80°  to  90°  C.  (176°  to  194°  P.)  and 
then  precipitate  as  pentanitrate  by  concentrated  sulphuric  acid  after 
cooling  to  0°  C. ;  after  mixing  with  a  larger  volume  of  water  and  wash- 
ing the  precipitate  with  water  and  then  with  alcohol,  it  is  dissolved  in 
ether-alcohol  and  again  precipitated  with  water,  when  it  is  obtained 
pure.  This  nitrate  is  insoluble  in  alcohol,  but  dissolves  readily  in  ether- 
alcohol  and  slightly  in  acetic  acid.  It  contains  12.75  per  cent,  nitrogen. 
Strong  potash  solution  converts  this  nitrate  into  the  dinitrate. 

The  tetranitrate  and  trinitrate  (collodion  pyroxyline)  are  generally 
formed  together  when  cellulose  is  treated  with  a  more  dilute  nitric  acid 
and  at  a  higher  temperature  and  for  a  much  shorter  time  (thirteen  to 
twenty  minutes)  than  in  the  formation  of  the  hexanitrate.  It  is  not 
possible  to  separate  them,  as  they  are  soluble  to  the  same  extent  in 
ether-alcohol,  acetic  ether,  acetic  acid,  or  wood-spirit.  On  treatment 
with  concentrated  nitric  acid  and  sulphuric  acids,  both  the  tri-  and 
tetranitrates  are  converted  into  pentanitrate  and  hexanitrate.  Potash 
and  ammonia  convert  them  into  dinitrate. 

The  dinitrate,  C12H1808(N03)2,  always  results  as  the  final  product 
of  the  action  of  alkalies  on  the  other  nitrates,  and  also  from  the  action 
of  hot,  somewhat  dilute  nitric  acid  upon  cellulose.  The  dinitrate  is  very 
soluble  in  ether-alcohol,  acetic  ether,  and  in  absolute  alcohol. 

The  chief  raw  material  for  the  manufacture  of  these  nitrates  at 
present  is  the  waste  from  cotton-spinning,  which  has  already  been  freed 
from  the  impurities  of  the  raw  cotton.  It  is  first  picked  clean  by  hand 
from  admixture  with  foreign  matter  and  then  torn  and  opened  up  by 
machinery  so  as  to  fit  it  for  easy  action  of  the  nitrating  acids.  It  is 
then  treated  for  a  few  minutes  with  boiling  potash  solution,  thoroughly 
washed,  and  dried  by  steam.  For  the  manufacture  of  celluloid  a 
specially  prepared  and  perfectly  pure  tissue-paper  is  now  used,  which 
is  torn  into  shreds  by  machinery  preparatory  to  the  nitrating. 

II.  Processes  of  Manufacture. 

1.  GUN-COTTON. — The  following  is  the  procedure  at  Waltham  Abbey, 
where  gun-cotton  is  made  for  the  English  government  under  Sir  F. 
Abel's  improved  method.  A  mixture  of  fifty-five  parts  of  nitric  acid 
(1.516  specific  gravity)  and  one  hundred  and  sixty-five  parts  of  sul- 
phuric acid  (1.842  specific  gravity)  is  taken  for  one  part  of  cotton.  The 


GUN-COTTON,  PYROXYLINE,  ETC.  329 

nitrating  mixture  is  placed  in  cast-iron  vessels,  cooled  from  without  by 
flowing  water,  and  the  cotton  immersed.  It  may  either  remain  in  these 
until  ready  for  washing,  or  may  after  a  brief  immersion  be  transferred 
to  smaller  stone-ware  vessels,  similarly  cooled,  in  which  it  then  remains 
for  twenty-four  hours,  for  the  double  purpose  of  completing  the  nitra- 
tion, so  that  the  product  shall  contain  a  maximum  of  the  highest,  or 
hexanitrate,  and  of  allowing  the  contents  of  the  jar  to  cool  down  per- 
fectly. The  nitrated  cotton  is  then  centrifugated,  stirred  up  thor- 
oughly with  cold  water,  again  centrifugated,  and  then  washed  system- 
atically with  warm  water  to  which  some  soda  has  been  added.  The 
gun-cotton  so  obtained  may  either  be  used  in  the  loose  form  or,  when 
designed  for  manufacture  into  cartridges,  is  beaten  in  a  hollander  after 
the  manner  of  paper-pulp,  and  then  washed  and  pressed  in  the  desired 
forms.  The  gun-cotton  when  finished  is  usually  preserved  in  a  moist 
state,  and  dried  only  when  needed  for  use.  It,  however,  does  not  require 
to  be  sharply  dried,  as  with  fifteen  to  twenty  per  cent,  of  moisture  it  can 
be  made  to  develop  its  full  explosive  powers. 

2.  PYROXYLINE  AND  COLLODION. — Pyroxyline  of  various  grades  of 
solubility  can  be  prepared  according  to  the  strength  of  acids  used  and 
length  of  immersion  given  the  cotton.  In  general,  the  nitric  acid  taken 
is  less  concentrated  than  that  used  for  making  gun-cotton,  and  a  some- 
what higher  temperature  is  employed.  Potassium  or  sodium  nitrate 
is  also  used  along  with  the  sulphuric  acid  as  the  nitrating  mixture,  as 
the  presence  of  nitrous  acid  in  the  nitric  acid  generated  is  considered 
as  playing  some  part  in  the  result.  A  mixture  of  twenty  parts  pul- 
verized potassium  nitrate  with  thirty-one  parts  of  sulphuric  acid  of 
1.835  specific  gravity  is  given  as  a  suitable  pyroxyline  mixture.  After 
the  nitre  has  entirely  dissolved  in  the  sulphuric  acid  and  the  mixture 
has  fallen  in  temperature  somewhat  below  50°  C.  the  cotton  is  put  in, 
stirred  around  thoroughly,  and  then  the  vessel  left  covered  for  twenty- 
four  hours  at  a  temperature  of  from  28°  to  30°  C.  The  pyroxyline  is 
then  washed  with  cold  water  until  it  shows  no  acid  reaction,  and  finally 
with  boiling  water  to  remove  the  last  traces  of  potassium  sulphate. 
A  similar  mixture,  using  sodium  nitrate,  is  thirty-three  parts  of  sul- 
phuric acid  of  1.80  specific  gravity,  seventeen  parts  of  sodium  nitrate, 
and  one-half  part  cotton. 

A  special  grade  of  pyroxyline  for  the  manufacture  of  collodion,  put 
upon  the  market  by  the  Schering  factory  in  Berlin,  is  made  by  immers- 
ing cotton  for  fifteen  minutes  in  a  mixture  of  equal  volumes  of  sulphuric 
acid  of  1.845  specific  gravity  and  nitric  acid  of  1.40  specific  gravity, 
taken  at  a  temperature  of  80°  C. 

The  pyroxyline  made  from  tissue-paper  for  the  celluloid  manufac- 
turers is  made  by  taking  fifty  cubic  centimetres  of  nitric  acid  of  1.47 
specific  gravity,  one  hundred  cubic  centimetres  nitric  acid  of  1.36  specific 
gravity,  and  one  hundred  cubic  centimetres  of  sulphuric  acid  of  1.84 
specific  gravity.  In  this  mixture  eighteen  grammes  of  the  finely-shredded 
tissue-paper  are  immersed  at  a  temperature  of  55°  C.  for  one  hour.  The 
paper  gains  about  forty  per  cent,  in  weight  in  the  nitration. 

The  method  of  carrying  out  this  nitration  as  proposed  by  Hyatt,  the 


330 


VEGETABLE  TEXTILE  FIBRES. 


patentee  of  celluloid,  is  shown  in  the  annexed  illustration.  (See  Fig. 
87.)  The  shredded  paper  is  filled  into  the  container  //,  in  which  has 
been  placed  a  mixture  of  strong  sulphuric  and  nitric  acids  heated  to 
from  26°  to  32°  C.  The  mixture  having  been  vigorously  stirred  by  a 
mechanical  stirrer  which  can  be  raised  and  lowered  at  will,  it  is  allowed 
to  remain  at  rest  for  twenty  minutes  to  allow  of  the  completion  of  the 
nitration.  It  is  then  swung  around  on  the  revolving  table  H1,  caught 
by  a  crane  from  above,  and  emptied  into  the  centrifugal  K,  which 
quickly  drains  off  the  excess  of  acid  from  the  mass,  the  liquid  flowing 
through  the  pipe  K1  into  the  reservoir  O1.  The  container  H  can  be 
filled  from  this  reservoir  through  the  pipe  K3  by  the  application  of  air 
pressure  at  M,  as  the  lid  of  the  acid  reservoir  is  fitted  on  air-tight.  O2 
is  a  reservoir  for  fresh  acid  mixture. 

The  proportions  of  ether  and  alcohol  used  in  dissolving  pyroxyline 
to  make  collodion  solutions  vary  very  greatly.  The  United  States  Phar- 
macopoeia prescribes  for  four  grammes  of  pyroxyline  seventy-five  cubic 


FIG.  87. 


centimetres  of  ether  and  twenty-five  cubic  centimetres  of  alcohol;  the 
British  Pharmacopoeia  takes  for  one  ounce  of  pyroxyline  thirty-six  fluid- 
ounces  of  ether  and  twelve  fluidounces  of  rectified  spirit;  the  German 
Pharmacopeia  takes  one  part  of  pyroxyline  to  twenty-one  parts  of  ether 
and  three  parts  of  alcohol. 

3.  CELLULOID. — The  conversion  of  pyroxyline  into  celluloid  is  accom- 
plished by  effecting  a  thorough  incorporation  with  the  former  of  a 
certain  amount  of  camphor.  This  may,  however,  be  done  in  a  number  of 
waySj  several  of  which  have  been  carried  out  in  practice.  First,  it  is 
possible  to  effect  it  by  heat  alone,  without  the  use  of  any  solvent  for 
either  the  camphor  or  the  pyroxyline.  The  camphor  at  the  temperature 
of  its  fusion  becomes  a  sufficient  solvent  for  tb^  pyroxyline  to  effect  com- 
plete physical  admixture.  This  process  is  essentially  that  used  in  this 
country.  The  weighed  amount  of  camphor  is  added  to  the  pyroxyline 
while  the  latter  is  still  in  a  partially  moist  condition,  some  alcohol 
sprinkled  upon  the  mixture  to  aid  in  the  comminution  of  the  camphor, 
and  the  materials  carefully  ground  together  in  closed  drums.  The 


GUN-COTTON,  PYROXYLINE,  ETC.  331 

mixture  may  now  be  put  through  heated  rolls  to  effect  the  melting  of 
the  camphor  and  cause  it  to  penetrate  and  take  up  the  pyroxyline  in 
every  part  of  the  mass.  It  is  then  put  through  a  heated  masticating 
machine  to  complete  the  admixing  and  make  the  mass  of  uniform  com- 
position throughout.  Coloring  matter  is  added  when  desired  to  the 
materials  before  the  camphor  takes  up  the  pyroxyline,  so  that  it  may 
be  thoroughly  distributed  or  dissolved  as  the  case  may  be. 

A  solution  of  camphor  in  either  ethyl  or  methyl  alcohol  has  also  been 
used  as  the  means  of  converting  the  pyroxyline  into  celluloid.  This 
may  be  either  with  the  aid  of  heat  or,  if  sufficient  of  the  solvent  be  used, 
it  may  be  carried  out  at  ordinary  temperatures. 

A  solution  of  camphor  in  ether  has  also  been  used  in  the  celluloid 
factory  of  Magnus  &  Co.  in  Berlin.  For  fifty  parts  of  pyroxyline  are 
taken  twenty-five  parts  of  camphor  dissolved  in  one  hundred  parts  of 
ether  to  which  five  parts  of  alcohol  have  been  added.  The  mixture  is 
covered  up  and  stirred  from  time  to  time.  A  gelatinous  and  glutinous 
mass  results,  which  must  be  rolled  between  calender  rolls  until  it 
acquires  plastic  characters.  The  process  is  distinctly  more  dangerous 
than  the  others  mentioned,  as  the  ether  is  all  allowed  to  evaporate,  and 
it  does  not  yield  anything  better  in  the  way  of  product. 

m.  Products. 

1.  GUN-COTTON. — The  explosive  variety  of  gun-cotton,  whether  in  the 
form  of  loose  fibre  or  as  compressed  cartridge  or  paper  sheets,  cannot  be 
readily  told  by  outward  characteristics  from  untreated  cotton.    On  close 
examination  a  slight  yellowish  tint  is  recognizable ;  it  is  slightly  rougher 
to  the  touch,  and  crinkles  slightly  when  pressed ;  when  rubbed  it  is  easily 
electrified  and  sticks  to  the  fingers.     When  lighted  it  burns  quickly 
without  smouldering  or  leaving  any  residue.     When  heated  slowly  it 
begins  to  decompose  with  evolution  of  acid  fumes,  and  above  130°  C.  it 
explodes.     It  is  therefore  necessary  to  exercise  great  care  in  the  drying 
of  it,  and  especially  if  all  traces  of  acid  have  not  been  removed.     It  is 
much  safer  when  wet  than  dry,  although  it  is  possible  to  explode  it  by  con- 
cussion when  it  still  contains  from  fifteen  to  twenty  per  cent,  of  water. 

The  explosive  variety  of  nitrocellulose  is  a  mixed  penta-  and  hexa- 
nitrate  and  contains  from  12.6  to  13.4  per  cent,  of  nitrogen. 

Gun-cotton  is  insoluble  in  water,  alcohol,  ether,  chloroform,  and 
acetic  acid,  in  dilute  acids  and  alkalies.  It  is  somewhat  soluble  in  ace- 
tone and  wood-spirit. 

Gun-cotton  is  chiefly  used  in  submarine  mines  and  blasting  and  for 
naval  torpedoes.  The  combination  of  it  with  nitro-glycerine,  known  as 
blasting  gelatine,  has  been  referred  to  under  another  section.  (See  p.  85.) 

2.  PYROXYLINE. — This    in    most   physical    characters   resembles   per- 
fectly the  explosive  gun-cotton.   The  most  important  difference  is  the 
ready  solubility  of  this  variety  of  cellulose  nitrate  in  a  mixture  of  alcohol 
and  ether,  in  which  the  higher  nitrate  is  insoluble.    The  ordinary  pyrox- 
yline  is,   moreover,   only   slightly   explosive.      When   dissolved   in   the 
strength  noted  before  (see  preceding  page)  we  obtain, — 


332  VEGETABLE  TEXTILE  FIBRES. 

3.  COLLODION. — This  is  a  colorless  liquid,  which  rapidly  evaporates 
on  exposure  to  the  air,  leaving  a  transparent  film  of  tetranitrate,  or 
tetra-  and  trinitrate  mixed,  insoluble  in  water  and  alcohol.    It  is  used  as 
a  dressing  for  wounds  under  the  name  of  " liquid  adhesive  plaster,"  and 
very  largely  in  photography  as  a  means  of  covering  the  photographic 
plates  with  a  transparent  film  which  shall  hold  finely  divided  and  dis- 
tributed the  sensitive  silver  salt. 

4.  PYROXYLINE  VARNISHES. — In  recent  years  a  very  important  class 
of  metal  varnishes  or  lacquers  have  been  introduced  under  trade-names, 
such  as  Zapon  varnish,  etc.,  in  which  pyroxyline  is  the  basis.     This  is 
dissolved  in  either  methyl  alcohol,  acetone,  methyl  and  amyl  acetates,  or 
mixtures  of  these.    Petroleum-naphtha  is  also  added  to  these  solvents  to 
facilitate  the  drying.      These  varnishes   are  of  special  value   for  fine 
metal-work  in  brass  or  bronze,  as  they  leave  a  perfectly  transparent  and 
flexible  film  of  pyroxyline,  which  protects  the  metal  and  will  not  crack 
or  peel  when  properly  applied. 

5.  CELLULOID. — This  valuable  product  of  the  action  of  camphor  upon 
pyroxyline  is  prepared  under  a  great  variety  of  forms,  both  transparent 
and  opaque,  colored  uniformly,  or  mottled  and  striated  in  imitation  of 
ivory,  coral,  amber,  tortoise-shell,  agate,  and  other  substances.    It  cannot 
be  caused  to  explode  by  heat,  friction,  or  percussion.    When  brought  in 
contact  with  flame  it  burns  with  a  rustling  flame,   and  continues  to 
smoulder  after  the  flame  is  extinguished,  the  camphor  being  distilled  off 
with  production  of  thick  smoke,  while  the  nitro-cellulose  undergoes  in- 
complete combustion. 

Celluloid  dissolves  in  warm,  moderately  concentrated  sulphuric  acid, 
but  is  carbonized  by  the  strong  acid.  It  is  readily  soluble  in  glacial 
acetic  acid,  and  on  diluting  the  solution  with  water  both  camphor  and 
pyroxyline  are  reprecipitated.  It  is  rapidly  soluble  in  warm,  moderately 
concentrated  nitric  acid  (four  volumes  of  fuming  acid  to  three  of  water), 
and  is  also  dissolved  with  ease  by  a  hot  concentrated  solution  of  caustic 
soda.  Ether  dissolves  out  the  camphor  from  celluloid,  and  wood-spirit 
behaves  similarly.  Ether-alcohol  (3:1)  dissolves  both  the  nitro-cellulose 
and  camphor,  leaving  the  coloring  and  inert  matters  as  a  residue.  The 
density  of  celluloid  ranges  from  1.310  to  1.393.  When  heated  to  125°  C., 
it  becomes  plastic  and  can  be  moulded  into  any  desired  shapes.  Sepa- 
rate pieces  can  also  be  welded  together  by  simple  pressure  when  at  this 
temperature.  The  celluloid  is  easily  cemented  to  wood,  leather,  etc.,  by 
the  use  of  collodion  or  a  solution  of  shellac  and  camphor  in  alcohol. 

IV.  Analytical  Tests  and  Methods. 

Pure  hexanitrate  of  cellulose  will  keep  indefinitely,  but  the  presence 
of  free  acid,  of  lower  nitrates,  or  of  fatty  and  waxy  matters  renders  it 
more  or  less  unstable,  and  therefore  unsafe.  The  most  important  deter- 
minations to  make  are  the  examination  for  free  acid  and  for  lower 
nitrates,  and  the  valuation  by  means  of  the  estimation  of  N02  liberated 
from  any  sample. 


ARTIFICIAL  SILK.  333 

1.  EXAMINATION  FOR  FREE  ACID. — This  may  be  detected  by  treating 
twenty  grammes '  weight  of  the  gun-cotton  with  fifty  cubic  centimetres  of 
cold  water.    After  twelve  hours  the  water  may  be  pressed  out,  filtered, 
and   twenty-five    cubic    centimetres    titrated    with    decinormal    caustic 
alkali.    With  the  remainder  of  the  liquid  the  nature  of  the  acid,  whether 
sulphuric  or  nitric,  may  be  ascertained  by  the  usual  tests. 

2.  EXAMINATION  FOR  LOWER  NITRATES. — These  may  be  detected  if 
present  by  treating  five  grammes  of  the  sample,  previously  dried  at 
100°  C.,  with  one  hundred  cubic  centimetres  of  a  mixture  of  three  parts 
of  ether  and  one  of  alcohol.     The  mixture  is  shaken  frequently  during 
twelve  hours,  and  then  rapidly  filtered  through  loosely-packed  glass- 
wool,  the  filtrate  evaporated  at  a  gentle  heat,  and  the  residue  weighed. 

3.  EXAMINATION  FOR  UNALTERED  CELLULOSE. — This  may  be  estimated 
by  treating  the  gun-cotton  left  undissolved  by  the  ether-alcohol  with 
acetic  ether,  which  dissolves  the  hexanitrate  and  leaves  the  unchanged 
cotton.    An  alternative  plan  is  to  prepare  a  solution  of  sodium  stannite 
by  adding  caustic  soda  to  a  solution  of  stannous  chloride  until  the  pre- 
cipitate at  first  formed  is  just  redissolved.     This  solution  when  boiled 
with   gun-cotton  dissolves  the  cellulose  nitrates  without  affecting  the 
unchanged  cellulose.    Sodium  sulphide  is  also  used  for  the  same  purpose. 

4.  VALUATION  BY  DETERMINATION  OF  NO2. — The  nitrogen  peroxide 
contained   in   gun-cotton   and  similar  nitrated  products   is   frequently 
determined  by  the  aid  of  the  reaction  of  sulphuric  acid  and  mercury 
upon  the  nitrates  as  carried  out  in  a  Lunge's  nitrometer.     This  is  a 
burette  provided  at  one  end  with  stopcock  and  funnel-tube  and  nar- 
rowed at  the  other  end,  which  is  connected  by  a  stout  piece  of  rubber 
tubing  with  a  simple  graduated  burette-tube.    The  burette  with  the  stop- 
cock is  filled  with  mercury  through  the  rubber  connection  with  the  other 
tube  and  the  stopcock  closed.     .35  gramme  of  gun-cotton,  dissolved  in 
five  cubic  centimetres  of  concentrated  sulphuric  acid,  are  then  put  into 
the  funnel-tube,  and  by  opening  the  stopcock  and  lowering  slightly  the 
connecting  burette  are  drawn  into  the  stoppered  tube,  washed  out  of 
the  funnel  with  a  little  additional  pure  sulphuric  acid,  and  the  stopcock 
closed.    The  tube  is  then  shaken  vigorously  until  the  reaction  is  complete 
and  the  volume  of  gas  no  longer  increases.    It  is  then  allowed  to  attain 
constant  temperature  and  the  volume  read  off  with  correction  for  tem- 
perature and  pressure.     Allen   (Commercial  Organic  Analysis,  2d  ed., 
vol.  i,  p.  328)    recommends  that  the  volume  be  compared  with  that 
yielded  by  a  standard  sample  or  a  nitre  solution. 

ARTIFICIAL  SILK. 
I.  Raw  Materials. 

The  manufacture  of  an  artificial  silk  (with  the  exception  of  one 
process,  not  now  commercially  followed — that  using  gelatine)  starts 
with  cellulose,  usually  in  the  form  of  the  cotton  fibre.  Three  processes 
have  been  developed,  until  at  present  they  have  assumed  what  may  be 
termed  an  international  importance  and  are  successfully  supplying  a 


334  VEGETABLE  TEXTILE  FIBRES. 

product  of  great  value  and  one  that  has  created  a  field  for  itself  in 
numerous  special  utilizations.  While  the  raw  material  is  primarily 
cellulose  in  all  cases,  in  two  of  the  processes  it  is  first  changed  into  a 
chemical  derivative  of  cellulose  which  is  afterwards  decomposed  in  the 
process  of  manufacture. 

1.  NITROCELLULOSE    OR    CHARDONNET    PROCESS. — The    starting-point 
of  this  process,  the  earliest  of  the  commercial  processes  (1888)  is  a  pure 
cellulose,  usually  cotton  fibre,  cleansed  both  mechanically  and  then  by 
treatment  with  weak  alkali  solutions.    This  is  then  carded  so  as  to  open 
it  up  and  nitrated,  as  already  described  in  the  manufacture  of  pyroxy- 
line  or  soluble  cotton.     The  washing,  of  the  nitrocellulose  must  be  very 
thorough,  so  that  every  trace  of  acid  is  removed.     When  washed  the 
wet  nitrocellulose  is  pressed  in  hydraulic  presses  until  the  per  cent,  of 
water  retained  is  reduced  to  thirty-six  per  cent.,  which  amount  remains 
in  it  until  after  the  spinning.     The  solution  of  this  is  then  effected  in  a 
mixture  of  equal  parts  of  ninety-five  per  cent,  alcohol  and  ether,  using 
one  hundred  litres  of  solvent  for  twenty-two  kilos,   of  nitrocellulose, 
reckoned  on  dry  weight.     This  solution  takes  place  in  horizontal  revolv- 
ing iron  cylinders  lined  with  tin  and  provided  with  mechanical  agita- 
tion.    From  fifteen  to  twenty  hours  slow  continued  revolution  of  the 
cylinder  is  usually  required  and  the  solution,  although  appearing  per- 
fectly clear,  is  nevertheless  filtered  to  remove  any  imperfectly  dissolved 
nitrocellulose.     The  solution  after  filtration  is  stored  in  large  containers 
to  "ripen,"  so  that  it  may  be  suited  for  the  spinning  process. 

2.  THE  CUPRAMMONIUM  PROCESS. — The  raw  material  is  here  also  a 
purified  cellulose.     Cotton  is  treated  with  an  alkaline  lye  to  bring  it 
into  a  pure  condition  easily  soluble  in  the  solvent,  which  in  this  case 
is  a  copper-oxide-ammonia  solution.     Pauly,  the  first  patentee  of  arti- 
ficial silk  of  this  kind,  prepared  his  solution  by  precipitating  cupric 
hydroxide  from   copper  sulphate   solution   with   ammonia   in   required 
amount,  washing  the  same  and  then  dissolving  it  in  aqua  ammonia  to 
clear  solution,  of  which  one  litre  contained  from  ten  to  fifteen  grammes 
of  copper.    This  is  then  allowed  to  act  on  the  moist  purified  cellulose  in 
a  hollander,  in  which  the  cellulose  solution  is  rapidly  effected.     Even 
after  perfect  solution  seems  to  have  been  effected,  this  must  be  filtered 
in  order  to  obtain  that  uniform  solution  needed  for  the  spinning  opera- 
tion.    A  later  process    (that  of  Bronnert,   Fremery  and  Urban)    pre- 
pares the  cuprammonium  solution  by  the  action  of  strong  ammonia 
water  on  metallic  copper  in  the  presence  of  a  current  of  air.     If  the 
temperature  is  kept  down  to  about  5°  C.  the  ammonia  in  the  presence 
of  air  has  a  rapid  solvent  action  on  the  copper,  and  solutions  containing 
eight  and  ten  per  cent,  of  copper  are  obtained. 

3.  THE  VISCOSE  PROCESS. — Cross,  Bevan,  and  Beadle  in  1892  dis- 
covered the  method  of  preparing  a  water-soluble  cellulose  xanthogenate 
by  the  reaction  of  carbon  disulphide  upon  alkali-treated  cellulose,  which 
compound  decomposes  with  the  liberation  of  carbon  disulphide,  leaving 
behind    a  pure  cellulose  in  gelatinous  form  mixed  with  the  alkali. 

For  the  manufacture  of  filaments  a  short-fibre  cellulose  is  chosen, 


ARTIFICIAL  SILK.  335 

which  is  mixed  with  the  required  amount  of  sodium  hydroxide  in  solu- 
tion and  allowed  to  react,  producing  a  swollen  mass  of  crumbling  granu- 
lated texture,  with  the  development  of  heat.  The  proportions  usually 
taken  are  air-dried  cellulose  25  to  33,  sodium  hydroxide  12.5  to  16,  water 
62  to  55.  The  carbon  disulphide  is  made  to  act  upon  the  soda-cellulose 
in  the  proportion  of  1  to  10.  The  proper  mixture  being  put  into  a 
wooden  rotating  drum  which  can  be  sealed,  the  reaction  takes  place 
rapidly  at  the  ordinary  temperature,  a  few  hours  sufficing  for  its  com- 
pletion. The  product  of  the  reaction  being  transferred  to  a  closed  vessel 
provided  with  mechanical  stirring  attachment,  water  is  gradually  added, 
when  the  mass  dissolves  to  a  viscid  jelly  which,  when  filtered,  is  ready 
for  the  spinning. 

II.  Processes  of  Manufacture. 

SPINNING  OF  THE  ARTIFICIAL  SILK  FILAMENT. — While  in  each  case  the 
spinning  is  effected  by  forcing  a  very  viscid  liquid  through  fine  jets  of 
glass  or  metal,  the  conditions  are  so  dissimilar  in  the  case  of  the  three 
different  raw  materials  that  the  process  will  be  described  as  applying 
to  each  material  in  turn. 

1.  The    Collodion   or   Chardonnet   Process. — The   collodion   filament 
solidifies  almost  in  the  moment  that  it  is  forced  out  of  the  jets.     The 
passing  of  the  filament  into  a  bath  of  acidified  water  is  no  longer  prac- 
tised, but  the  filament  goes  into  the  air,  liberating  the  vapors  of  alcohol 
and  ether  which  are  carried  along  by  a  current  of  warm  air  and  pass 
through  condensation  and  absorption  vessels,  the  first  containing  soda 
and  the  second  sulphuric  acid  which  absorbs  the  vapors  of  ether.     The 
Chardonnet  filament   is,   however,    a   nitrocellulose   which   when   dried 
thoroughly  is  extremely  inflammable,  so  that  it  is  necessary  to  denitrate 
it.    This  is  done  by  the  action  of  alkaline  sulphides,  such  as  ammonium 
sulphide.     Following  this  a  slight  bleaching  is  necessary,  as  the  ammo- 
nium sulphide  leaves  the  filament  yellow.     A  very  small  amount  of 
bleaching  powder  and  muriatic  acid  suffices  to  bring  the  silk  to  a  white 
color,  when  it  is  finally  washed  and  dried. 

2.  The  Cuprammonium  Process. — The  material  which  is  forced  from 
the  spinning  jet  in  this  case  is     cellulose  in  ammoniacal  cupric-oxide 
solution.     So  to  form  the  filament  it  must  be  delivered  into  a  solution 
which  will  act  at  once  to  decompose  it  and  liberate  the  cellulose,  which 
then  forms  a  filament  semisolid  at  first  but  becoming  stronger  as  it  loses 
the  water  with  which  it  is  charged.     Pauly  first  used  fifteen  per  cent, 
sulphuric  acid  as  the  ingredient  of  the  decomposing  bath.     This  forms 
cupric  and  ammonium  sulphates,  both  soluble,  while  the  cellulose  fila- 
ment when  thoroughly  washed  free  from  acid  is  dried  under  tension  and 
yields  a  product  of  silky  lustre  that  requires  no  denitrating  or  bleaching 
to  finish  it. 

Bronnert,  Fremery,  and  Urban  later  improved  this  procedure  by 
using  fifty  per  cent,  sulphuric  acid  in  the  decomposing  bath,  which  gave 


336  VEGETABLE  TEXTILE  FIBRES. 

them  a  firmer  filament,  and  then,  after  washing  this,  drying  it  in  two 
stages,  first  in  a  current  of  air  at  the  ordinary  temperature  and  then 
in  heated  rooms  at  40°  C. 

3.  Viscose  Process. — The  separation  of  cellulose  from  viscose  solu- 
tions takes  place  so  readily  that  at  first  it  was  sought  to  simply  spin 
the  filament  from  the  fine  jets  into  a  vertical  shaft  or  air-passage 
through  which  warm  air  was  rising,  but  now  it  is  effected  according  to 
the  Stearns'  process  by  spinning  the  filament  into  a  solution  of  ammo- 
nium chloride,  which  causes  a  complete  separation  of  the  cellulose  of  the 
filament.  It  is  left  in  a  cold  ammonium  chloride  bath  for  several  hours, 
brought  into  boiling  ammonium  chloride  for  a  few  minutes  and  then 
thoroughly  washed. 

m.  Products. 

Artificial  silk  as  a  commercial  product  is  of  a  uniform  white  color 
and  possesses  the  characteristic  lustre  of  natural  silk.  Chardonnet  silk 
indeed  possesses  a  higher  lustre  than  the  natural,  although  it  does  not 
have  the  rustle  of  true  silk  and  is  somewhat  harder  to  the  touch; 
cuprammonium  silk  (the  German  glanz-stoff),  on  the  other  hand,  has 
more  exactly  the  lustre  as  well  as  the  rustle  of  natural  silk;  viscose  silk 
resembles  the  collodion  silk. 

Several  points  of  difference  in  physical  characters  between  natural 
and  artificial  silk  are  thus  given  by  Silvern :  * 

Absorption  of 
moisture  in 

Percentage  moist  room  of 
Specific  of  moisture  silk  dried  at 
gravity.  at  99°C.  110°-115°. 

Natural  raw  silk  1.36  7.97  20.11 

Chardonnet  silk    (1)    1.52  10.37  27.46 

Chardonnet  silk  (2)    1.53  11.17  28.94 

Lehner   silk    1.51  10.71  26.45 

Cuprammonium  silk   ( Glanz-stoff )    1.50  10.04  23.08 

Gelatine  silk    1.37  13.02  45.56 

Viscose    11.44  

That  artificial  silk  fibres  lose  notably  in  strength  on  wetting  is  one 
of  their  distinguishing  characters  as  compared  with  natural  silk  fibre. 
The  average  loss  in  strength  on  wetting  is  given  as  seventy  per  cent,  for 
all  varieties.  A  treatment  of  artificial  silk  with  a  formaldehyde  bath 
to  correct  this  defect  has  been  proposed  by  Escalier  and  is  known  as 
"sthenosizing."  It  is  claimed  that  fibres  so  treated  lose  very  little  of 
their  strength  on  wetting. 

From  the  chemical  point  of  view  the  most  important  difference 
between  artificial  silk  (the  gelatine  silk  excepted)  and  natural  silk  is 
that  while  natural  silk  contains  some  seventeen  per  cent,  of  nitrogen, 
the  artificial  silk  contains  only  traces  of  this  element.  They  therefore 
behave  to  chemical  reagents  like  the  vegetable  cellulose  fibres. 

*  Die  Kunstlicke  Seide,  Dr.  Carl  Silvern,  2te  Auf.,  p.  220. 


BIBLIOGRAPHY  AND  STATISTICS.  337 

IV.  Analytical  Tests  and  Methods. 

There  are  a  number  of  reagents  that  will  distinguish  between  natural 
and  artificial  silk.  Strong  potassium  hydroxide,  solution,  which  will  dis- 
solve natural  silk,  will  only  swell  more  or  less  the  artificial  silks,  with 
the  exception,  of  course,  of  gelatine  silk. 

Alkaline  copper-glycerine  solution  will  dissolve  natural  silk  (both 
the  true  and  the  tussah  silk)  but  does  not  attack  the  artificial  silk  con- 
sisting of  cellulose. 

Diphenylamine  sulphate,  however,  is  one  of  the  best  of  the  reagents 
for  the  detection  of  artificial  silk.  Its  reaction  is  as  follows: 

With  natural  silk   Brown  coloration. 

With  tussah  silk  Intense  brown  coloration. 

With  Chardonnet  and  Lehner  silk Intense  blue. 

With  Pauly  or  Thiele  cupraramonium  silk No  reaction. 

With  viscose  silk No  reaction. 

It  is  claimed  that  artificial  silk  is  more  easily  affected  by  heat  than 
either  cotton,  wool,  or  natural  silk  fibre.  On  heating  a  fabric  containing 
mixed  fibres  to  200°  C.,  the  artificial  silk  will  be  destroyed  and  the  dust 
can  be  beaten  or  brushed  out  and  the  loss  in  weight  give  the  proportion 
of  the  artificial  silk  originally  present. 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

1873. — Die  Gespinnstfasern,  R.  Schlesinger,  Zurich. 

Die  Pflanzenfasern,  Hugo  Mtiller,  Leipzig. 
1874. — Etudes  sur  le  Travail  des  Lins,  A.  Renouard,  Paris. 
1876. — Etudes  sur  les  Fibres  v6g6tales  textiles,  M.  Ve"tillard,  Paris. 
1877. — Die  Pflanzenfasern,  Hugo  Miiller    (and  Hofmann's  Entwickelung  der  Chem- 
Ind. ) ,  Braunschweig. 

Die  Fabrikation  des  Papiers,  L.  Miiller,  Berlin. 
1878. — Cotton  from  Seed  to  Loom,  William  B.  Dana,  New  York. 
1881. — Matieres  premieres  organiques,  G.  Pennetier,  Paris. 

Die  Gewinnung  der  Gespinnstfasern,  H.  Richard,  Braunschweig. 
1882. — Structure  of  the  Cotton  Fibre,  F.  Bowman,  Manchester. 

Chevallier's  Dictionnaire  des   Falsifications,   Baudrimont,  Paris. 

Etude  sur  les  Textiles  tropicaux,  A.  Renouard,  Lille. 
1884. — Ueber  pflanzliche  Faserstoffe,  V.  von  Hohnel,  Wien. 

Ramie,  Rhea,  Chinagras  und  Nesselfaser,  Bouche  und  Grothe,  Berlin. 

Cotton-Spinning,  R.  Marsden,  London. 

Guide  pratique  de  la  fabrication  du  Papier,  A.  Proteaux,  Paris. 
1885. — The  Dyeing  of  Textile  Fabrics,  J.  J.  Hummel,  London. 
1886. — Handbuch  der  Papierfabrikation,   S.  Mierzinski,  Wien. 

The  Manufacture  of  Paper,  Charles  T.  Davis,  Philadelphia. 
1887. — Report  on  Indian  Fibres  and  Fibrous  Substances,  Cross  and  Bevan,  London. 

Die  microskopische  Untersuchung  des  Papiers,  J.  Wiesner,  Leipzig. 

Die  Fabrikation  des  Papiers,  Egbert  Hoyer,  Braunschweig. 

Microscopie  der  Faserstoffe,  F.  von  Hohnel,  Wien. 

The  Practical  Paper-Maker,  J.  Dunbar,  3d  ed.,  London. 
1888. — A  Text-Book  on  Paper-Making,  Cross  and  Bevan,  London. 

Die  chemische  Technolgie  der  Gespinnstfasern,  Otto  Witt,  Braunschweig. 

Die  Jute  und  ihre  Verarbeitung,  E.  Pfuhl,  Bd.  i.,  Berlin. 

Papier  priifung,  W.  Herzberg,  Berlin. 

22 


338  VEGETABLE  TEXTILE  FIBRES. 

1890. — Report  on  Flax,  Hemp,  Ramie,  etc.,  United  States  Department  of  Agriculture, 

Washington,  D.  C. 

The  Cotton  Fibre,  its  Structure,  etc.,  Hugh  Monie,  Jr.,  Manchester.  . 
The  Art  of  Paper-Making,  Alex.  Watt,  London. 

1892. — Explosives  and  their  Powers,  M.  Bethelot,  trans,  by  Hake  and  McNab,  Lon- 
don. 

Index  to  Literature  of  Explosives,  C.  E.  Munroe,  Washington. 
Taschenbuch  fur  den  praktischen  Papier  Fabrikanten,  C.  F.  Dahlheim,  2te 

Auf.,  Miinchen. 
1893. — Textiles  Vegetaux,  E.  Lecompte,  Paris. 

Examen  microscopique  des  textile  fibres,  R.  Schlesinger,  traduit  par  L.  Gau- 

tier,  Paris. 

Modern  High  Explosives,  M.  Eissler,  3d  ed.,  New  York. 
1894.— Das  Celluloid,  Dr.  Fr.  Bockmann,  2te  Auf.,  Wien. 

The  Chemistry  of  Paper-Making,  Griffin  and  Little,  New  York. 
1895. — Cellulose,  Cross  and  Bevan,  London  and  New  York. 
Die  Baumwolle,  Th.  Otto  Schweitzer,  Bern. 
A  Treatise  on  Paper-Making,  C.  Hoffman,  New  York. 
The  Manufacture  of  Explosives,  O.  Guttmann,  2  vols.,  New  York. 
1896. — Nitro-Explosives,  P.  Gerald  Sanford,  London. 
1897. — Hand-Book  of  Modern  Explosives,  M.  Eissler,  2d  ed.,  London. 

A  Treatise  on  Paper,  R.  Parkinson,  3d  ed.,  London. 
1898. — Cotton,  its  Uses,  Varieties,  Fibre,  etc.,  C.  P.  Brooks,  Lowell  and  New  York. 

The  Technical  Testing  of  Yarns  and  Textile  Fabrics,  J.  Herzfeld,  trans,  by 

Charles  Salter,  London. 

1900. — Die  Rohstoffe  des  Pflanzenreiches,  J.  Wiesner,  2te  Auf.,  Leipzig. 
1904. — Cellulose,  Cellulose  Production,  etc.,  Dr.  Josef  Bersch,  Wien. 
1906. — Researches  on  Cellulose,  C.  F.  Cross  and  E.  J.  Bevan,  vol.  ii,  London. 

Nitro-explosives,  Smokeless   Powders,  and  Celluloid,  P.  G.   Sanford,  2d  ed., 

London. 

Die  Zellulose-fabrikation,  Max  Schubert,  3te  Auf.,  von  M.  Knosel,  Berlin. 
Die  Viskose,  ihre  Harstellung,  etc.,  Dr.  B.  Margosches,  2te  Auf.,  Leipzig. 
1907. — Celluloid,  its  Raw  Materials,  Manufacture,  etc.,  Fr.  Bochmann,  translated  by 

Chas.  Salter,  London. 

Practical  Paper-making,  G.  Clapperton,  2d  ed.,  London. 
Papier  priifung,  Wilhelm  Herzberg,  3te  Auf.,  Berlin. 
1908. — The  Paper-Mill  Chemist,  H.  P.  Stevens,  London. 
1909. — The  Textile  Fibres,  their  Physical,  Microscopical  and  Chemical  Properties,  J. 

Merritt  Matthews,  2d  ed.,  J.  Wiley  &  Son,  New  York. 
The  Manufacture  of  Paper,  R.  W.  Sindall,  London. 

1910. — Die  Cellulosebearbeitung  und  chemischen  Eigenschaften,  C.  Wiest,  Stuttgart. 
Le  Celluloid,  Fabrikation,  Application,  Substituts,  etc.,  Masselon,  Roberts  et 

Cillard,  Paris. 

1911. — The  Nitrocellulose  Industry,   E.   C.   Worden,   2  vols.,   Van   Nostrand,   New 
York. 

STATISTICS. 

I.   a.   PRODUCTION,   CONSUMPTION   AND   EXPORTATION   OF   COTTON   FROM   THE   UNITED 

STATES. 


Year. 
1905     

Domestic  con- 
Production  (in   sumption  (bales    Exportations            Value  of 
bales  of  500  Ibs.)      of  500  Ibs.)      (  bales  of  500  Ibs.)    exportations. 

10,804,556         4,877,465         6,975,494         $401,005,921 

1906     

13,595,498         4,974,199         8,825,237           481,277,797 

1907     

11,375,461         4,493,028         7,779,508           437,788,202 

1908     

13,587,306         5,198,963         8,889,724           417,390,665 

1909     . 

.    10.315,382                                  5.491,842           450,447,243 

BIBLIOGRAPHY  AND  STATISTICS. 


339 


I.    6.   COTTON   CONSUMPTION   BY   COUNTRIES,   1905   AND   1900.       (IN   BALES   OF  500  LBS.) 


Country.  1905. 

United  States   4,310,000 

United  Kingdom    3,620,000 

Continent  of  Europe  5,148,000 

East  Indies   1,350,000 

Japan    875,000 

Canada    130,000 

Mexico 70,000 

Other   countries    35,000 


Total 


1900. 

3,856,000 

3,334,000 

4,576,000 

1,139,000 

712,000 

105,000 

18,000 

33,000 


,  15,538,000  13,773,000 

(Census  Bureau,  1905.) 


II.  FLAX. — According  to  a  United  States  consular  report  from 
Odessa  (United  States  Consular  Reports,  March,  1891,  p.  365),  the  total 
area  sown  in  Europe  with  flax  amounted  to  5,700,000  acres,  of  which 
Russia  alone  had  3,700,000  acres.  The  total  quantity  of  flax  fibre  pro- 
duced in  Europe  is  there  given  as  follows: 


Pounds. 

Russia    900,000,000 

Austria-Hungary    104,400,000 

Germany    97,200,000 

France    79,200,000 

Ireland    46,800,000 


Pounds. 

Belgium    43,200,000 

Italy    43,200,000 

All  other  countries    36,000,000 


1,350,000,000 


The  world's  production  of  flax  is  thus  stated  by  J.  Scott  Keltic  (The 
Statistician's  Year-Book,  London,  1907) : 


Tons. 

Russia    350,000 

Germany    44,000 

France   ( 1905)    20,645 

North  America  20,000 


Tons. 


Great    Britain    and    Ireland 

(1908)    9,080 

Italy    5,200 


The  importation  of  flax  into  the  United  States  was  as  follows : 


1906.  1907.  1908. 

Amount  in  tons  . . .  8,729  8,656  9,528 

Value    $2,327,300     $2,086,205     $2,514,680 


1909.  1910. 

9,890  12,761 

$2,542,256     $3,417,321 


III.  a.  The  importations  of  other  vegetable  fibres  have  been : 


Hemp  (dutiable)    . 
Value    

1906. 
5,317 
$906,808 

1907. 
8,718 
$1,534,371 

1908. 
6,213 
$1,086,805 

1909. 
5,208 
$799,164 

1910. 
6,423 
$1,039,833 

Hemp  (Manila)    .. 
Value    

58,738 
$11,036,667 

54,513 
$10,876,107 

52,233 
$8,974,617 

61,622 
$7,156,091 

92,507 
$10,517,100 

Jute  (  tons  )       .... 

103,945 

104,489 

107,533 

156,685 

68,155 

Value     

$6,449,684 

$8,950,684 

$6,504,920 

$7,216,307 

$3,728,448 

Sisal  grass    (tons) 
Value    . 

98,037 
$15,282.308 

99,061 
$14,959,415 

103,994 
$14,047,369 

91,451 
$10,215,887 

99,966 
$11,440,521 

340  VEGETABLE  TEXTILE  FIBRES. 

III.  &.  Production  and  exportation  of  jute  from  India : 

Production  in  Export  in 

1000  cwts.  1000  cwts. 

1905  29,075  12,875 

1906  32,880  14,480 

1907  35,064  15,970 

1908  22,539  14,192 

1908  17,880 

(Statistical  Abstracts  for  British  Colonies,  London,  1909.) 

IV.  Paper  and  Pulp  Statistics: 

The  importations  of  crude  paper  stock  (rags,  etc.)  and  of  wood-pulp 
in  recent  years  have  been : 

Crude  paper  stock.  Wood-pulp. 

1904  $2,900,713  289,592,000  Ibs.,  valued  at  $3,602,668 

1905    3,796,595  335,008,000     "  "  4,500,955 

1908   3,675,926             532,031,360     "  "            7,313,326 

1909    3,638,034             614,244,972     "  "            8,629,263 

1910   5,206,877             847,440,759     "  "          11,768,014 

(Commerce  and  Navigation  of  U.  S.,   1910.) 

The   production   of  wood-pulp,   according  to   Census   Reports,  has 
been: 

Ground  wood-pulp.          Soda-fibre.  Sulphite-fibre.  Total. 

1900    586,374  tons         177,124  tons         416,037  tons         1,179,535  tons 

1905    968,976  tons         196,770  tons         756,022  tons         1,921,768  tons 


RAW  MATERIALS.  341 


CHAPTER    IX. 

TEXTILE  FIBRES  OF  ANIMAL  ORIGIN. 

As  before  stated,  the  only  animal  fibres  that  have  acquired  technical 
importance  are  the  wool  fibre  and  silk.  These  will  now  be  considered. 

I.  Raw  Materials. 

A.  WOOL. — Wool  is  undoubtedly  a  variety  of  hair,  found  in  greater 
or  less  quantity  on  almost  all  mammals,  on  a  few  of  which,  as  the 
domestic  sheep,  it  forms  the  principal  covering  of  the  body.  It  is 
probable  that  while  both  hair  and  wool  occur  together  in  wild  sheep, 
domestication  has  gradually  caused  the  rank  hairy  fibres  to  disappear 
and  the  soft  under- wool  to  develop  until  the  fleece  of  wool  becomes  a 
thick  and  complete  covering.  From  ordinary  hair  the  wool  is  distin- 
guished by  two  important  properties :  First,  while  hair  is  almost  smooth 
on  the  surface,  the  wool  fibre  is  covered  by  minute  overlapping  scales 
arranged  like  roof-tiles.  While  these  scales  are  so  minute  as  not  to  be 
discernible  to  the  eye,  they  can  be  felt  if  a  woollen  fibre  is  drawn  between 
the  fingers  in  the  direction  opposite  to  that  in  which  the  scales  are  set. 
Secondly,  while  a  hair  is  perfectly  straight,  the  woollen  fibre  is  finely 
crimped  or  curled,  so  that  it  becomes  longer  when  drawn  out  and 
shortens  again  when  the  strain  is  removed.  The  spring  due  to  this 
curled  structure  gives  woollen  fabrics  notable  elasticity.  Owing  to  the 
overlapping  scale-like  structure  and  the  crimpled  condition  of  the  fibre, 
wool  has  also  the  power  of  felting,  or  becoming  matted  into  a  compact 
cloth  under  the  fulling  process  without  the  necessity  of  weaving.  These 
structural  characters  of  the  wool  fibre  are  shown  in  Fig.  88. 

Sheep's  wool  varies  from  the  long  straight  coarse  hair  of  certain 
varieties  of  the  English  sheep  (Leicester,  Lincolnshire,  etc.)  to  the  com- 
paratively short  wavy  fine  soft  wool  of  the  Spanish  and  Saxon  Electoral 
sheep.  According  to  the  average  length  of  the  fibres  or  staples  two 
principal  classes  of  wool  are  established,  the  long-stapled  (eighteen  to 
twenty-three  centimetres)  and  the  short-stapled  wools  (two  and  five- 
tenths  to  four  centimetres).  The  former  class  have  hitherto  been 
combed  and  then  spun  into  worsted  yarn,  while  the  latter  have  been 
carded  and  spun,  yielding  woollen  yarns.  These  processes  will  be  re- 
ferred to  again  later.  (See  p.  350.)  In  general  the  long  straight  wools, 
like  Lincoln  and  Leicester  wools,  possess  a  silky  lustre,  and  are  known 
as  lustre  wools,  while  the  Merino,  Colonial,  etc.,  which  are  shorter  and 
curly,  are  known  as  non-lustre  wools. 

The  worth  of  any  grade  of  wool  is  determined  by  noting  such  prop- 
erties as  softness,  fineness,  length  of  staple,  waviness,  lustre,  strength, 
elasticity,  flexibility,  color  and  the  facility  with  which  it  can  be  dyed. 


342  TEXTILE  FIBRES  OF  ANIMAL  ORIGIN. 

Wool  is  very  hygroscopic.  In  warm  dry  weather  it  may  contain  eight 
to  twelve  per  cent,  moisture  but  if  kept  for  a  time  in  a  damp  atmos- 
phere it  may  take  up  thirty  to  fifty  per  cent.  This  becomes  an  important 
item  in  the  sale  of  wool,  and  hence  in  France  and  Germany  the  per- 
centage of  moisture  contained  in  wool  to  be  sold  must  be  officially  deter- 
mined in  "wool-conditioning"  establishments.  (See  silk-conditioning, 
p.  348.)  The  legal  amount  of  moisture  allowed  on  the  Continent  is 
18.25  per  cent. 

The  best  kind  of  wool  is  colorless,  but  inferior  grades  are  often 
yellowish,  and  sometimes  even  brown  or  black  in  color. 

The  chemical  composition  of  the  wool  fibre  is,  as  already  noted  (see 
p.  302),  nitrogenous,  but  we  must  at  the  same  time  distinguish  between 
the  true  fibre  and  the  encrusting  matters.  These  latter,  independent 
of  mechanically  adhering  impurities  or  ' '  dirt, ' '  are  of  twofold  character, 
the  "wool-fat"  (soluble  in  ether)  and  the  "wool-perspiration"  (soluble 
in  water).  These  two  are  frequently  included  together  under  the  name 
of  the  "yolk"  or  "suint"  of  the  wool.  The  true  wool  fibre,  when 
cleansed  from  these,  has  approximately  the  following  composition :  Car- 
bon, 49.25  per  cent. ;  hydrogen,  7.57  per  cent. ;  oxygen,  23.66  per  cent. ; 
nitrogen,  15.86  per  cent. ;  sulphur,  3.66  per  cent.  The  presence  of  sul- 
phur is  very  distinctive  of  wool  and  serves  to  distinguish  it  from  silk, 
the  other  nitrogenous  fibre.  It  can  be  removed  in  large  part,  but  not 
without  weakening  the  fibre  and  destroying  its  lustre,  etc. 

Wool-fat  is  a  mixture  of  a  solid  alcoholic  body,  cholesterine,  together 
with  isocholesterine  and  the  compounds  of  these  bodies  with  several  of 
the  fatty  acids.  These  free  higher  alcohols  are  soluble  in  boiling  ethyl 
alcohol,  while  the  compounds  they  form  with  the  fatty  acids  are  insoluble 
in  alcohol  but  soluble  in  ether. 

Wool-perspiration  has  been  shown  to  consist  essentially  of  the  potas- 
sium salts  of  oleic  and  stearic  acids,  possibly  other  fixed  fatty  acids, 
also  potassium  salts  of  volatile  acids,  like  acetic  and  valerianic  acid,  and 
small  quantities  of  chlorides,  phosphates,  and  sulphates.  The  wash- 
water  of  raw  or  greasy  wool,  it  will  be  seen,  therefore,  would  contain 
large  amounts  of  potash  salts,  and  when  evaporated  and  ignited  would 
yield  an  abundant  product  of  potassium  carbonate.  This  utilization  of 
the  wool  wash-water  as  carried  out  at  present  in  France  and  Belgium 
yields  over  one  million  kilos,  of  potassium  carbonate.  Another  utiliza- 
tion of  this  yolk  of  wool  is  to  submit  it  to  dry  distillation,  when  it  yields 
a  residue  which  is  an  extremely  intimate  mixture  of  carbonate  of  potash 
and  nitrogenous  carbon,  of  great  value  for  the  manufacture  of  yellow 
prussiate  of  potash. 

Wool  is  decomposed  by  heat  at  130°  C.,  ammoniacal  vapors  are  given 
off,  and  at  140°  to  150°  C.  sulphur  compounds  are  also  present  in  the 
vapors.  When  ignited  by  a  flame,  wool  emits  the  disagreeable  odor  of 
burnt  feathers  and  leaves  a  porous  caked  residue.  Ammoniacal  solu- 
tion of  cupric  hydroxide  has  no  action  upon  wool  in  the  cold,  but  dissolves 
it  when  hot.  Dilute  solutions  of  hydrochloric  and  sulphuric  acids  have 
little  influence  whether  hot  or  cold.  This  fact  is  availed  of  in  separating 


RAW  MATERIALS. 


343 


cotton  from  wool  in  the  process  of  "carbonizing"  mixed  cotton  and 
woollen  goods.  The  dilute  sulphuric  acid  used  attacks  and  disintegrates 
the  cotton.  They  are  then  dried  in  closed  chambers  at  110°  C.,  after 
which  the  disorganized  cotton  can  be  beaten  out,  while  the  wool  remains 
but  slightly  altered.  Nitric  acid  does  not  attack  the  wool  seriously,  but 
gives  it  a  yellow  color,  hence  sometimes  used  as  a  ' '  stripping ' '  agent  for 
dyed  woollen  goods  in  case  of  re-dyeing.  Sulphurous  acid  is  the  most 
satisfactory  bleaching  agent  for  woollens,  as  it  removes  the  natural 
yellow  tint  of  the  ordinary  wool.  Caustic  alkalies  act  rapidly  and  in- 
juriously upon  wool.  Alkaline  carbonates  and  soap  have  little  or  no 
injurious  action  if  not  too  concentrated  and  if  the  temperature  is  not 
above  50°  C.  Chlorine  and  hypochlorites  act  injuriously  upon  wool  and 
cannot  be  used  for  bleaching.  A  very  slight  action  of  chlorine,  on  the 
other  hand,  causes  wool  to  assume  a  yellowish  tint  and  gives  it  an 
increased  affinity  for  many  coloring  matters. 


FIG.  88. 


FIG.  89. 


Sheep's  wool  (sf°). 


Alpaca  goat's  hair  (3f  °). 


Closely  related  to  sheep's  wool  are  a  few  varieties  of  animal  hair, 
which  are  also  utilized  in  some  degree  as  textile  fibres  in  similar  classes 
of  goods. 

Mohair  is  the  product  of  the  Angora  goat  of  Asia  Minor  and  Cape 
Colony,  South  Africa.  It  is  a  long  silky  hair,  which  is  very  soft  and 
lustrous. 

Cashmere  consists  of  the  soft  under-wool  which  grows  in  winter  on 
the  Cashmere  goat.  It  furnishes  the  material  for  the  costly  Cashmere 
shawls  of  native  manufacture,  but  is  not  exported  at  all  as  fibre. 

Alpaca,  Vicuna,  Llama,  and  Guanaco  are  the  names  of  four  closely- 


344  TEXTILE  FIBRES  OF  ANIMAL  ORIGIN. 

related  species  of  South  American  goats  found  on  the  western  slopes  of 
the  Andes,  which  yield  valuable  hair-like  fibres.  Of  these,  the  alpaca  is 
exported  in  largest  amount  to  Europe  and  the  United  States.  It  is  a 
long  silky  fibre  somewhat  intermediate  between  true  wool  and  hair  and 
possessing  a  strong  lustre.  It  is  both  white  and  of  various  colors.  It  is 
shown  in  Fig.  89. 

Camel's  Hair  is  somewhat  used  in  Africa,  Asia  Minor,  and  the  Cau- 
casus, and  latterly  in  Europe,  for  the  manufacture  of  woven  goods, 
which  are  made  from  the  unbleached  hair. 

B.  SILK. — The  silk  fibre  is,  morphologically,  the  simplest  and  at  the 
same  time,  because  of  its  properties,  the  most  perfect  of  the  textile 
fibres.  It  differs  from  all  the  other  fibres  in  that  it  is  found  in  nature 
as  a  continuous  fine  thread,  so  that  the  process  of  spinning  is  super- 
fluous in  its  case.  In  place  of  this  we  have  the  reeling  process,  whereby 
several  of  the  natural  threads  are  united  into  one  thicker  and  stronger 
thread. 

Silk  is  the  product  of  the  silk-worm  (Bombyx  mori)  and  is  simply 
the  fibre  which  the  worm  spins  around  itself  for  protection  when  enter- 
ing the  pupa  or  chrysalis  state.  From  the  eggs  laid  by  the  animal  in 
the  moth  or  butterfly  state  develops  the  caterpillar  or  silk-worm.  The 
eggs  are  yellowish  in  color  at  first,  changing  to  gray  when  dry.  They 
are  very  light  in  weight,  some  thirteen  hundred  and  fifty  together  weigh- 
ing one  gramme.  For  the  development  of  the  caterpillar  from  them  a 
certain  amount  of  warmth  and  moisture  is  necessary,  the  temperature 
being  raised  in  the  incubation  chamber  during  ten  or  twelve  days  from 
18°  to  25°  C.  The  young  worms  are  at  once  removed  to  larger  chambers, 
where  are  lath  frame-works  strung  across  with  threads  and  sheets  of 
paper.  The  animals  are  placed  upon  these,  and  fed  regularly  during 
thirty  to  thirty-three  days,  till  indeed  they  begin  to  spin.  They  are  here 
fed  upon  mulberry  leaves  (Morus  alba},  and  during  this  period  increase 
enormously  in  size,  becoming  at  length  about  eight  to  ten  centimetres 
long  and  about  five  grammes  in  weight.  To  allow  of  this  increase  in 
size  it  casts  its  skin  some  four  times  during  this  period  (at  intervals  of 
from  four  to  six  days).  When  about  the  thirtieth  day  of  its  growth  has 
been  reached  it  ceases  to  take  food  and  shows  a  decided  restlessness.  It 
is  then  placed  on  birch-twigs,  and  soon  begins  to  spin.  This  spinning  of 
the  cocoon,  or  oval-shaped  house  in  which  the  worm  is  to  undergo  the 
chrysalis  state  before  emerging  as  the  butterfly,  involves  the  secretion 
of  the  fibre  so  much  prized  as  silk.  The  silk  substance  is  secreted  by  two 
glands,  one  on  either  side  of  the  body  of  the  caterpillar.  The  substance 
from  these  two  glands  unites  in  a  capillary  canal  situated  in  the  head  of 
the  animal,  whence  issues  the  silk  as  a  double  fibre  only  rarely  separated, 
cemented  throughout  by  the  sericin,  or  silk-glue.  ^The  microscopical  ap- 
pearance of  the  silk  fibre  is  shown  in  Fig.  90.  This  fibre  which  goes  to 
form  the  cocoon  varies  in  length  from  three  hundred  and  fifty  to  twelve 
hundred  and  fifty  metres,  and  has  a  diameter  which  averages  about  .018 
millimetre.  The  interlacing  layers  of  the  silk  cocoon  are  at  first 
loose,  but  become  finer  and  denser  towards  the  interior,  while  the  inner- 


RAW  MATERIALS. 


345 


FIG.  91. 


most  layer  which  immediately  surrounds  the  animal  forms  a  thin 
parchment-like  skin.  The  several  stages  of  cocoon-spinning  are  shown 
in  Fig.  91.  The  cocoons  of  the  female  are  pure  oval  in  shape,  while  those 
of  the  male  are  distinctly  contracted  in  the  centre.  They  are  white  or 
yellowish,  and  usually  about  three  centimetres  long  and  one  and  one- 
half  to  two  centimetres  thick.  Some  seven  or  eight  days  are  allowed  for 
the  completion  of  the  cocoon-spinning,  and  they  are  then  gathered.  A 
sufficient  number  of  both  males  and  females  are  taken  for  breeding  pur- 
poses, and  the  rest  put  aside 
to  be  reeled  for  silk.  Those 
chosen  for  breeding  are  kept 
for  some  twenty  days  at  a 
temperature  of  from  19°  to 
20°  C.,  when  the  silk-moth 
which  has  formed  in  the  inte- 
rior from  the  pupa  emits  a 
peculiar  saliva,  which  softens 
the  sericin,  or  silk-glue,  at 

FIG.  90. 


Silk  fibre  (»|°). 


one  end  of  the  cocoon  and  enables  the  animal  to  push  its  way  out  to  day- 
light. The  females  within  forty  hours  after  their  appearance  lay  their 
eggs,  some  four  hundred  in  number,  and  shortly  after  die.  The  eggs 
are  slowly  dried,  and  stored  in  glass  bottles  in  a  dry  dark  place  till  the 
following  spring.  The  cocoons  put  aside  for  the  reeling  of  silk  must 
be  taken  in  hand  promptly  and  the  chrysalis  contained  in  them  killed, 
in  order  to  prevent  the  development  of  the  silk-moth  and  the  injury  to 
the  cocoon  by  its  pushing  its  way  out.  This  is  done  either  by  heating 
them  for  several  hours  in  an  oven  at  60°  to  70°  C.,  or  more  quickly  by 


346  TEXTILE  FIBRES  OF  ANIMAL  ORIGIN. 

steam  heat.  One  hundred  grammes  of  eggs  produce  under  favorable 
conditions  from  ninety  thousand  to  one  hundred  and  seventeen  thousand 
cocoons,  weighing  one  hundred  and  fifty  to  two  hundred  kilos.,  and 
these  yield  twelve  to  sixteen  kilos,  of  reeled  silk. 

The  silk  fibre  consists  to  the  extent  of  rather  more  than  half  its 
weight  of  fibroin,  C15H23N506,  a  nitrogenous  principle.  Covering  this 
is  the  silk-glue,  or  sericin,  C1DH25N508.  Whether  this  latter  exists  in  the 
glands  of  the  silk-worm  along  with  the  fibroin,  as  maintained  by  Duseig- 
neur-Kleber,  or  is  produced  exclusively  by  atmospheric  change  from 
the  fibroin  as  asserted  by  Bolley,  is  still  in  debate.  This  sericin,  how- 
ever, is  easily  dissolved  off  from  the  fibroin  by  warm  soap-water  and 
other  alkaline  liquids.  This  ' ' boiled-bff "  liquid  plays  an  important  part 
in  silk-dyeing  operations.  (See  p.  544.)  The  most  important  physical 
properties  of  the  silk  fibre  are  its  lustre,  strength,  and  avidity  for  mois- 
ture. The  regulation  of  the  amount  of  moisture  contained  in  raw  silk 
as  offered  for  sale,  or  "silk-conditioning,"  will  be  spoken  of  under  the 
process  of  treatment.  (See  p.  348.) 

Besides  the  true  silk,  the  product  of  Bombyx  mori,  we  have  several 
so-called  "wild  silks,"  the  most  important  of  which  is  the  Tussur  silk, 
the  product  of  the  larva  of  the  moth  Antheraa  .mylitta,  found  in  India. 
The  cocoons  are  much  larger  than  those  of  the  true  silk-worm,  egg- 
shaped,  and  of  a  silvery  drab  color.  They  are  also  attached  to  the  twigs 
of  the  food  trees  by  a  thread-like  prolongation  of  the  cocoon.  The 
cocoon  is  very  firm  and  hard,  and  the  silk  is  of  a  drab  color.  It  is  used 
for  the  buff-colored  Indian  silks,  and  latterly  largely  in  the  manufacture 
of  silk  plush.  Other  wild  silks  are  the  Eria  silk  of  India,  the  Muga 
silk  of  Assam,  the  Atlas  or  Fagara  silk  of  China,  and  the  Yama-mai  silk 
of  Japan. 

n.  Processes  of  Manufacture. 

It  will  be  beyond  the  province  of  this  work  to  take  up  the  manu- 
facture of  woollen  and  silk  goods  from  the  mechanical  side.  Hence  we 
shall  only  notice  the  preliminary  processes  of  chemical  treatment  which 
the  fibres  undergo  to  prepare  them  for  manufacture  into  goods,  and 
then  take  up  the  several  classes  of  manufactured  textiles  again  in  speak- 
ing of  bleaching  and  dyeing  of  goods. 

A.  WOOL. — 1.  Wool-scouring. — The  condition  of  the  raw  wool  when 
first  obtained  from  the  back  of  the  sheep  has  already  been  referred  to. 
The  fibre  is  covered  with  both  natural  and  artificial  impurities  (yolk, 
dirt,  etc.)  to  such  an  extent  that  mordanting  and  dyeing  would  be  almost 
impossible.  These  are  therefore  to  be  removed  by  the  process  of  scour- 
ing. It  will  be  remembered,  too,  that  the  yolk  was  stated  to  be  made  up 
of  the  wool-fat  (soluble  in  alcohol)  and  the  wool-perspiration  (soluble 
in  water).  Both  of  these  have  to  be  removed  in  the  completed  scouring 
operation.  The  full  operation  then  must  include  three  stages,— viz., 
steeping,  or  washing  with  water  (desuintage}  ;  cleansing  or  scouring 
proper  with  weak  alkaline  solutions  (degraissage}  ;  rinsing  or  final  wash- 
ing with  water  (ringage).  The  first  operation  may  be  omitted  if  the 


PROCESSES  OF  MANUFACTURE.  347 

wool  has  been  washed  by  the  wool-grower.  This  is  true,  for  instance, 
with  Australian  wools,  while,  on  the  other  hand,  most  South  American 
wools  come  into  commerce  unwashed  and  very  rich  in  yolk.  The  wash- 
ing of  these  wools  is  largely  carried  on  in  France  and  Belgium,  and, 
as  has  been  stated  (see  p.  342),  is  made  to  yield  large  amounts  of  potas- 
sium carbonate  by  evaporating  and  igniting  the  wash-waters.  The  wool 
is  systematically  washed  in  tepid  water  (about  45°  C.)  in  a  series  of 
tanks  arranged  so  that  the  water  passes  from  one  to  the  other  until 
completely  saturated,  when  it  is  evaporated.  According  to  M.  Chan- 
delon,  one  thousand  kilos,  of  raw  wool  may  furnish  three  hundred  and 
thirteen  litres  of  yolk  solution  of  specific  gravity  1.25  (50°  Tw.),  having 
a  value  of  fifteen  shillings  and  sixpence,  while  the  cost  of  extraction 
does  not  exceed  two  shillings  and  sixpence. 

The  scouring  and  washing  processes  for  loose  wool  are  usually  carried 
out  in  the  well-known  rake  scouring-machines,  consisting  of  a  large 
cast-iron  trough  provided  with  an  ingenious  system  of  forks  or  rakes 
whereby  the  wool  is  gradually  passed  forward  by  the  to-and-fro  digging 
motion  of  the  rakes.  Two  or  three  such  scouring-machines  are  placed 
in  series,  so  that  the  first  may  take  the  bulk  of  the  impurities,  the  second 
complete  the  scouring,  and  the  third  effect  a  thorough  washing  in  a 
stream  of  fresh  water.  The  scouring  liquid  which  has  been  longest  in 
use  is  stale  urine  (lant),  which  is  effective  because  of  the  ammonium 
carbonate  it  contains.  It  is  now  largely  supplanted  by  ammonia,  sodium 
carbonate,  soaps,  etc.  The  most  injurious  effects  arise  from  the  use  of 
water  containing  lime  or  magnesia,  because  of  the  formation  of  the 
insoluble  lime  or  magnesia  compounds  upon  the  fibre.  In  recent  years 
volatile  solvents,  like  petroleum-naphtha,  carbon  disulphide,  and  carbon 
tetrachloride,  have  also  been  introduced  for  scouring  purposes,  although 
not  generally  adopted  on  account  of  the  expense  and  risk  attending  their 
use.  They  must  be  followed  at  all  events  by  a  washing  with  water,  as, 
while  they  dissolve  fatty  matters,  they  do  not  take  up  the  oleates,  etc., 
of  the  wool-perspiration. 

The  only  treatment  of  this  kind,  known  technically  as  a  degreasing 
process,  is  that  with  petroleum-naphtha.  This  has  been  found  prac- 
ticable and  remunerative.  The  wool,  freed  from  its  grease  and  wax- 
like  constituents  by  the  naphtha  and  its  potash  salts,  by  a  washing  with 
water  only  is  left  in  an  excellent  condition  for  the  mechanical  treatment, 
such  as  carding  and  combing. 

Woollen  yarns  and  woollen  cloth  are  also  scoured  to  free  them  from 
the  oil  which  has  either  purposely  or  by  accident  been  put  upon  them 
in  the  spinning  and  weaving  operations.  The  scouring  of  "union" 
goods — that  is,  materials  with  cotton  warp  and  woollen  weft — is  a  more 
difficult  operation  on  account  of  the  differences  in  elasticity,  hygro- 
scopic character,  etc.,  of  the  cotton  and  the  wool  fibre.  It  includes  the 
operations  of  crabbing,  steaming,  and  scouring. 

2.  Bleaching  Wool. — Wool  is  generally  bleached  either  as  yarn  or 
cloth.  The  bleaching  agent  in  general  use  is  sulphur  dioxide.  It  may 
of  course  be  applied  either  as  gas  or  as  sulphurous  acid  solution,  the 


348  TEXTILE  FIBRES  OF  ANIMAL  ORIGIN. 

former  method  being  generally  followed,  and  the  yarn  or  cloth  suspended 
on  poles  in  closed  chambers,  called  sulphur-stoves,  which  can  be  charged 
with  the  gas.  In  liquid  bleaching  with  sulphurous  acid,  a  solution  of 
sodium  bisulphite  is  generally  used,  which  is  either  mixed  with  an 
equivalent  amount  of  hydrochloric  acid  or,  what  is  better,  the  goods  are 
passed  through  one  solution  after  the  other  in  separate  baths.  The 
bleaching  of  sulphur  dioxide  differs  essentially  from  that  effected  by 
chlorine  and  hypochlorites  in  that  it  is  not  due  to  oxidation,  but  to 
reduction  or  possibly  to  the  formation  of  colorless  compounds  with  the 
natural  yellow  color  of  the  wool.  At  all  events,  it  is  not  permanent  in 
character,  and  the  yellow  color  gradually  returns  on  exposure  to  atmos- 
pheric influences  and  repeated  washings  in  alkaline  solutions. 

The  best  liquid  bleaching  agent  is  hydrogen  dioxide.  The  woollen 
material  is  steeped  for  several  hours  in  a  dilute  and  slightly  alkaline 
solution  of  the  commercial  H202  and  then  well  washed,  first  with  water 
acidified  with  sulphuric  acid  and  afterwards  with  pure  water. 

B.  SILK. — 1.  Reeling  of  Silk. — The  unwinding  of  the  long  silk  fibre 
from  the  cocoon  and  bringing  it  into  condition  for  weaving  is  to  be 
accomplished  in  the  reeling  process.  The  cocoons  are  thrown  into  a 
basin  of  warm  water  to  soften  the  silk-glue  and  allow  of  the  fibres  being 
separated.  From  four  to  eighteen  fibres,  according  to  the  quality,  are 
taken,  and  two  threads  formed  by  passing  the  fibres  together  through 
two  perforated  agate  guides.  After  being  crossed  or  twisted  together 
at  a  given  point  they  are  again  separated  and  passed  through  a  second 
pair  of  guides,  thence  through  the  distributing  guides  on  to  the  reel. 
The  temporary  twisting  or  crossing  causes  the  agglutination  of  the  indi- 
vidual fibres  of  each  thread.  In  order  to  form  long  threads  a  frequent 
adding  on  the  fibre  of  a  new  cocoon  is  necessary.  Care  must  be  taken, 
also,  that  the  thread  remain  as  nearly  as  possible  of  uniform  thickness, 
so  that  as  the  inner  fine  fibres  of  several  cocoons  come  through  the 
guides  another  cocoon  is  added  to  the  number  used  for  the  thread.  One 
cocoon  gives  .16  to  .20  or  at  most  .25  gramme  of  raw  silk.  The  loss 
through  removal  of  the  external  floss  varies  from  eighteen  to  thirty  per 
cent.,  according  to  the  cocoons  and  the  care  bestowed  by  the  worker. 
Before  this  raw  silk  can  be  used  for  weaving  two  of  the  threads  are 
"thrown"  together  and  slightly  twisted. 

2.  Silk-conditioning. — Raw  silk  kept  in  a  humid  atmosphere  is 
capable  of  absorbing  thirty  per  cent,  of  its  weight  of  moisture  without 
this  being  at  all  perceptible.  It  therefore  becomes  a  matter  of  great 
importance  for  the  buyer  to  know  what  weight  of  normal  silk  there  is  in 
any  given  lot.  To  ascertain  this  with  accuracy,  there  have  been  estab- 
lished in  a  number  of  the  European  centres  of  silk  industry  conditioning 
establishments.  The  operation  is  carried  out  by  means  of  the  apparatus 
shown  in  Fig.  92,  where  a  number  of  hanks  of  silk  are  shown  in  the 
drying  chamber.  A  test  hank  of  silk  is  taken  from  the  bale,  and  having 
been  suspended  from  the  one  arm  of  an  accurate  balance  its  initial 
weight  is  gotten.  It  is  then  dried  in  a  current  of  air  at  110°  C.  until 
constant  weight  is  again  obtained.  The  arrangement  of  the  drying 


PROCESSES  OF  MANUFACTURE. 


349 


FIG.  92. 


chamber  is  shown  in  the  illustration.  To  the  final  weight  obtained  for 
the  dry  silk  eleven  per  cent,  is  added,  and  the  result  taken  as  a  normal 
silk  weight.  The  average  loss  of  weight  in  this  conditioning  process  is 
about  twelve  per  cent. 

3.  Silk-scouring. — By  the  scouring  of  silk  the  silk-glue  is  removed 
to  a  greater  or  less  extent  and  the  fibre  is  rendered  lustrous  and  soft  and 
able  to  take  the  dye-color.  According  to  the  amount  of  silk-glue  removed 
in  this  operation  the  product  is  called  boiled-off  silk,  souple  silk,  or  ecru. 
In  the  first  case,  the  loss  of  silk-glue  amounts  to  twenty-five  to  thirty 
per  cent,  of  the  weight  of  the  raw 
silk;  in  the  second,  to  eight  to  twelve 
per  cent. ;  and  in  the  third  to  three  to 
four  per  cent,  of  the  original  weight 
of  the  silk.  In  preparing  the  first 
variety  two  operations  are  necessary, 
stripping  or  ungumming  (degom- 
mage),  and  boiling  off. 

The  hanks  of  raw  silk  are  sus- 
pended by  wooden  rods  in  a  rectan- 
gular trough  lined  with  copper  and 
worked  by  hand  in  a  thirty  to  thirty- 
five  per  cent,  soap  solution  heated  to 
90°  to  95°  C.  When  the  water  is  very 
hard  it  must  be  corrected  or  softened 
previously.  Frequently  two  soap- 
baths  are  used  one  after  the  other  as 
the  first  one  becomes  charged  with  the 
silk-glue.  The  silk  at  first  swells  up 
and  becomes  glutinous,  but  as  the 
glue  dissolves  off  it  becomes  soft  and 
silky.  The  waste  soapy  and  glutin- 
ous liquid  obtained  is  called  "boiled- 
off"  liquor,  and  is  a  useful  addition 
to  the  dye-bath  in  dyeing  with  coal- 
tar  colors.  (See  p.  544.)  For  the  purpose  of  removing  the  last  portions 
of  the  silk-glue,  it  is  now  washed  in  water  at  60°  C.,  to  which  some  soap 
and  carbonate  of  soda  have  been  added,  then  put  in  coarse  hempen  bags 
called  "pockets"  and  boiled  for  half  an  hour  to  three  hours,  according 
to  quality,  in  open  copper  vessels  with  a  solution  of  ten  to  fifteen  per 
cent,  of  soap.  It  is  then  rinsed  with  a  weak  tepid  solution  of  sodium 
carbonate,  and  finally  washed  in  cold  water.  Silk  intended  to  remain 
white  or  to  be  dyed  pale  colors  is  then  at  once  bleached  while  moist  with 
gaseous  sulphur  dioxide  for  some  six  hours.  The  bleaching  operation 
may  be  repeated  from  two  to  three  times,  according  to  the  quality  of 
the  silk. 

Souple  silk  is  that  which  has  been  prepared  for  dyeing  with  a  loss 
of  not  more  than  eight  per  cent,  of  its  weight.  It  is,  however,  not  so 
strong  as  boiled-off  silk,  and  is  used  only  for  tram.  Its  preparation 


350  TEXTILE  FIBRES  OF  ANIMAL  ORIGIN. 

always  includes  two  operations,  and  if  the  silk  is  to  be  dyed  light  colors, 
two  additional  operations  have  to  be  carried  out.  The  raw  silk  is  first 
" softened,"  and  the  small  quantity  of  fatty  matter  present  removed 
(degraissage)  by  working  it  from  one  to  two  hours  in  a  ten  per  cent, 
soap  solution  at  25°  to  35°  C.  It  is  then  "bleached"  by  immersion  for 
ten  to  fifteen  minutes  in  a  dilute  solution  of  aqua  regia  (five  parts  hydro- 
chloric acid  to  one  part  nitric),  or  as  a  substitute  for  this  nitrated  sul- 
phuric acid  (nitrosyl-sulphate).  This  is  followed  by  "stoving, "  or 
treatment  with  sulphur  dioxide,  and  then,  without  removing  the  sul- 
phurous acid,  by  the  treatment  of  soupling  (assouplissage)  proper. 
This  consists  in  working  the  silk  for  about  an  hour  and  a  half  at  90° 
to  100°  C.  in  water  containing  three  to  four  grammes  cream  of  tartar  to 
the  litre.  This  treatment  makes  the  silk  softer  and  causes  it  to  swell  up 
and  become  more  absorbent.  It  is  then  finally  washed  in  tepid  water. 

Ecru  silk  is  raw  silk  which  has  been  washed  with  hot  water,  with  or 
without  soap,  bleached  with  sulphur,  and  again  washed.  It  is  only  used 
for  a  base  for  other  silk  fabrics  like  velvet  or  dyed  in  blacks. 

Artificial  silk  has  already  been  described  in  detail  under  the  vege- 
table fibres  and  the  products  therefrom  (see  p.  333.) 

HE.  Products. 

A.  WOOL. — We  have  already  alluded  to  the  distinction  between 
worsted  and  woollen  yarns.  Formerly  all  long-stapled  wools  were 
combed, — that  is,  the  fibres  were  brought  as  nearly  as  possible  parallel 
to  one  another  and  were  then  spun  into  what  was  known  as  worsted 
yarn,  used  in  hoisery  and  in  the  manufacture  of  fabrics  which  did  not 
undergo  fulling.  All  short-stapled  wools,  on  the  other  hand,  were  carded 
and  spun  much  as  cotton  is  spun,  and  the  yarns  so  obtained  were  the 
only  ones  capable  of  being  used  in  making  milled  or  fulled  cloths,  in 
which  the  felting  property  of  wool  is  availed  of  to  thicken  the  cloth 
after  weaving  and  in  which  by  teasels  the  nap  of  the  cloth  is  raised  so 
as  to  present  a  uniform  surface.  All  kinds  of  wool,  therefore,  were 
formerly  divided  into  combing  and  carding  or  clothing  wools.  Machines 
have  been  invented  latterly,  however,  capable  of  combing  wools  having 
as  short  a  staple  as  one  inch,  and,  on  the  other  hand,  wools  with  a  staple 
as  much  as  five  inches  long  may  be  used  in  making  milled  cloth.  So  the 
distinction  between  the  several  wools  is  no  longer  as  absolute  as  it 
once  was. 

Among  the  chief  kinds  of  worsted  fabrics  are  serges  and  merinos  and 
mixed  goods  of  wool  and  mohair,  alpaca,  and  camel 's  hair.  Hosiery  and 
carpets  also  belong  here,  although  the  best  of  these  latter  are  made  on  a 
ground  of  strong  linen  or  hemp.  The  principal  varieties  of  woollen 
cloth  are  broadcloths,  the  finest  variety  of  woollen  cjoth,  cashmeres,  a 
fine  thin  twilled  fabric,  tweeds,  fabrics  of  looser  texture  than  broadcloth 
and  less  highly  milled,  doeskin,  a  strong  twilled  cloth,  blankets,  flan- 
nels, etc. 

Shoddy  is  a  material  made  from  fragments  of  cast-off  woollen  cloth- 
ing torn  into  fibres  and  re-spun  into  yarn.  It  is  looser  in  texture  than 


ANALYTICAL  TESTS  AND  METHODS. 


351 


mungo,  which  is  made  from  remains  of  finer  fragments,  such  as  old 
dress-coats,  tailor's  clippings,  etc. 

A  third  grade  of  recovered  wool,  sometimes  called  extract  wool,  is 
obtained  from  union  goods  (mixed  woollen  and  cotton  goods)  by  the 
process  of  carbonizing  the  vegetable  fibre  and  then  beating  it  out.  The 
carbonizing  is  done  with  dilute  sulphuric  acid,  with  aluminum  chloride, 
or  with  gaseous  hydrochloric  acid.  The  last  process  is  said  to  give  the 
best  results. 

B.  SILK. — The  raw-silk  threads  obtained  in  the  reeling  process  are 
not  sufficiently  strong  for  use  in  the  loom,  so  several  must  be  united. 
This  may  be  done  in  different  ways.  By  the  union  of  two  or  more  single 
threads,  separately  twisted  in  the  same  direction,  which  are  then  doubled 
and  retwisted  in  the  opposite  direction,  is  obtained  organzine.  The  best 
grades  of  silk  are  also  taken  for  the  organzine,  which  is  to  form  the  warp 
in  silk-weaving.  The  product  of  the  union  of  two  or  more  simple  un- 
twisted threads  which  are  then  doubled  and  singly  twisted  is  tram,  which 
forms  the  weft  in  wreaving. 

Waste  silk  is  that  which  proceeds  from  perforated  and  double  cocoons 
and  such  as  are  soiled  in  steaming  or  in  any  other  way.  This  waste 
silk  is  washed,  boiled  with  soap,  and  dried.  When  carded  and  spun  like 
cotton  it  yields  the  so-called  flurt-silk. 

Satins  are  tissues  so  woven  that  almost  the  only  threads  appearing 
on  the  right  side  of  the  tissue  are  weft  threads,  which  present  a  uniform 
glossy  surface. 

Velvets  are  tissues  in  which  the  outer  surface  presents  to  view  a 
short  soft  pile,  made  by  passing  the  warp  threads  over  fine  wires,  which 
are  afterwards  drawn  out.  The  loops  then  remaining  are  either  left  as 
they  are,  in  which  case  the  tissue  is  called  pile-velvet,  or  cut  to  form 
cut-velvet.  This  fabric  is  now  largely  imitated  in  cotton  and  mixed 
tissues. 

IV.  Analytical  Tests  and  Methods. 

GENERAL  DISTINCTIONS  BETWEEN  VEGETABLE  AND  ANIMAL  FIBRES. — 
A  general  scheme  for  distinguishing  between  the  several  classes  of  fibres 
has  been  proposed  by  R.  Schlesinger  in  his  "Leitfaden  fur  die  mikro- 
skopische  und  mikrochemische  Analyse  der  technisch  verwendeten 
Rohstoffe  der  Textil-Industrie. "  It  is  in  outline  as  follows : 


TREAT  WITH  CAUSTIC  SODA. 

The  fibre  does  not  dissolve  in 
ten  per  cent,  caustic  soda 
solution,  and  in  burning, 
which  takes  place  readily, 
does  not  develop  any  burnt 
horn  odor. 

Vegetable  fibres. 

The  fibre  dissolves  in  concen- 
trated  caustic    soda,   and 
when  treated  with  ammo- 
niacal  cupric  oxide  shows 
scales  upon  its  surface. 

Animal  hairs  or  wool. 

The  fibre  does  not  dissolve  in 
cold  ten  per  cent,  caustic 
soda,   but    dissolves   per- 
fectly in  concentrated  sul- 
phuric acid  ;  shows  neither 
scales  nor  medullary  sub- 
stance. 

Silks. 

352  TEXTILE  FIBRES  OF  ANIMAL  ORIGIN. 

The  vegetable  fibres  are  then  to  be  studied  by  the  aid  of  the  iodine  and  dilute  sul- 
phuric acid  reaction,  and  the  several  groups  already  noted  in  the  classification  on  p.  303 
are  established. 

The  animal  hairs  are  to  be  distinguished  best  by  the  microscopical  characters  and 
measurements. 

The  several  varieties  of  silk  are  also  to  be  distinguished  by  a  comparison  of  the  diame- 
ters of  the  fibre  as  measured  under  the  microscope. 

A  scheme  for  distinguishing  between  the  more  important  textile  fibres, 
based  upon  their  behavior  to  the  two  dyes  malachite-green  and  Congo- 
red,  and  after  examination  under  the  microscope,  has  been  proposed  by 
Behrens  ("Microchemische  Analyse,"  2te  Heft,  p.  51).  The  grouping 
thus  established  is  as  follows : 

Group  A.     Dyed  fast  to  washing  by  malachite- green. 
Here  belong,  of  the  textile  fibres,  silk,  wool,  and  jute. 

Aa.     Not  capable  of  supplementary  dyeing  by  aromatic  amines:  silk  and 

wool. 

Ab.     Capable  of  supplementary  dyeing  by   aromatic  amines :    jute. 
Group  B.     Dyed  partially  fast  only  by  malachite- green. 
Hemp  and  manila. 

Ba.     Strongly   polarizing:    hemp. 
Bb.     Weak    polarizing:    manila. 

Group  C.     Fugitive  dyeing  with  malachite- green;  complete  supplementary  dye- 
ing with  benzidine  dyes. 
Here  belong  cotton  and  flax. 
Ca.     Weak  polarizing:  cotton. 
Cb.     Strongly  polarizing:  flax. 

Several  of  the  simpler  differences  between  the  vegetable  and  the 
animal  fibres  as  groups  have  already  been  alluded  to  in  classifying  the 
fibres.  (See  p.  302.)  Other  special  tests  are  as  follows : 

1.  Millon's   reagent    (mercurous  and   mercuric  nitrate)    colors   the 
animal  fibres  red,  but  not  the  vegetable  fibres. 

2.  Liebermann  gives  the  following  test:    Prepare  a  fuchsine  solu- 
tion, add  potash  solution  drop  by  drop  until  it  is  decolorized,  filter,  and 
dip  in  the  sample  of  goods.    Wool  or  silk  fibres  are  colored  red,  cotton 
remains  colorless. 

3.  Ammoniacal  cupric  oxide  solution  dissolves  cotton  as  well  as  silk. 
While  cotton,  however,  is  precipitated  by  certain  salts  as  well  as  by 
sugar  and  gum,  silk  is  only  precipitated  by  acids. 

4.  As  wool  always  contains  sulphur,  a  sodium  plumbate   solution 
(made  by  boiling  red  lead  with  caustic  soda  solution  and  filtering)   is 
at  once  blackened  on  contact  with  wool.     This  test  may  be  interfered 
with  in  the  presence  of  sulphur-treated  silk. 

5.  Wool  and  silk  may  be  distinguished  by  the  use  of  hot  hydro- 
chloric acid.     Silk  dissolves  easily  in  this,  while  wool  merely  swells  up 
but  does  not  dissolve. 

6.  According  to  Hohnel,  wild  silks  behave  differently  from  true  silks 
with  chromic  acid.     If  a  cold  saturated  solution  of  chromic  acid  be 
diluted  with  an  equal  bulk  of  water  and  then  boiled  for  one  minute  with 
the  sample  of  silk,  the  true  silk  dissolves  up,  while  the  wild  silk  remains 
unattacked  even  after  two  or  three  minutes'  boiling.     Wool  behaves 
like  true  silk  in  this. 


BIBLIOGRAPHY  AND  STATISTICS.  353 

A.  Eemont  gives  a  process  for  determining  wool,  silk,  and  cotton 
when  mixed  in  the  same  fabric.  Four  pieces  of  about  two  grammes' 
weight  each  are  taken ;  three  of  these  are  boiled  for  a  quarter  of  an  hour 
in  two  hundred  cubic  centimetres  of  three  per  cent,  hydrochloric  acid, 
which  is  renewed  if  the  liquid  becomes  strongly  colored,  and  the  samples 
are  then  well  washed.  The  dressing  is  thus  removed  and  the  coloring 
matter  in  the  case  of  the  cotton,  but  only  slightly  in  the  case  of  wool 
and  silk;  the  weighting  of  the  silk  with  iron  salts  is  also  completely 
removed  by  the  hydrochloric  acid  if  the  weighting  does  not  exceed 
twenty-five  per  cent,  of  the  weight  of  the  silk,  leaving  the  fibres  chest- 
nut-brown in  color.  Two  of  the  samples  thus  treated  are  dipped  for 
one  to  two  minutes  into  a  boiling  solution  of  basic  chloride  of  zinc  of 
specific  gravity  1.69 ;  then  thrown  into  water  and  washed  first  with 
acidified  water  and  then  with  pure  water.  This  removes  the  silk.  The 
basic  chloride  of  zinc  solution  is  prepared  by  heating  one  thousand  parts 
of  zinc  chloride,  forty  parts  of  zinc  oxide,  and  eight  hundred  and  fifty 
parts  of  water. 

One  of  the  two  samples  freed  from  silk  is  then  boiled  gently  for  a 
quarter  of  an  hour  with  sixty  to  eighty  cubic  centimetres  of  caustic 
soda  solution  of  specific  gravity  1.02.  This  is  best  done  with  inverted 
condenser,  so  that  an  injurious  concentration  of  the  soda  solution  is 
avoided.  "Wash  gently  without  too  much  rubbing  and  the  wool  is 
removed.  All  four  samples  are  now  washed  for  a  quarter  of  an  hour 
with  distilled  water,  pressed  out,  dried  in  the  air,  and  weighed.  The 
first  will  weigh  as  before,  two  grammes  or  nearly,  a  slight  difference  of 
a  few  milligrammes  being  neglected;  the  difference  in  weight  between 
the  first  and  second  samples  gives  the  dressing ;  that  between  the  second 
and  third  gives  the  silk;  that  between  the  third  and  fourth  the  wool 
present,  and  the  weight  of  the  fourth  sample  the  vegetable  fibre  present. 
This  is  slightly  attacked  by  the  soda  solution,  and  in  the  case  of  cotton 
it  is  usual  to  reckon  five  per  cent,  as  the  loss  from  this  cause. 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

1867. — Einleitung  in  die  technische  Microscopie,  J.  Wiesner. 

1869. — Darstellung  der  Baues  und  der  Eigenschaften  der  Merinowolle,  M.  Settegast, 

Berlin. 

1873. — Die  Gespinnstfasern,  R.  Schlesinger,  Zurich. 
1874:. — Die  Wollgarnfarberei,  Richter  und  Braun,  Berlin. 
1878. — Le  Conditionnement  de  la  Soie,  J.  Persoz,  Paris. 
1880. — The  Woollen  Thread:   its  Nature,  Structure,  etc.,   C.  Vickerman.  Hudders- 

field. 
1881. — Die  Gewinnung  der  Gespinnstfasern,  H.  Richard,  Braunschweig. 

Matieres  premi&res  organiques,  Pennetier,  Paris. 

The  Wild  Silks  of  India,  Th.  Wardle,  London. 

1882. — Chevallier's  Dictionnaire  des  Falsifications,  4me  6d.,  Baudrimont,  Paris. 
1885. — The  Dyeing  of  Textile  Fabrics,  J.  J.  Hummel,  London. 

The  Structure  of  the  Wool  Fibre,  F.  H.  Bowman,  Manchester. 

L'Art  de  la  Soie,  N.  Rondot,  Paris. 

Les  Soies,  N.  Rondot,  Paris. 

23 


354  TEXTILE  FIBRES  OF  ANIMAL  ORIGIN. 

1886. — The  Catalogue  of  the  Silk-Culture   Court,  Indian  Exhibition,  Th.  Wardle, 

London. 

1887. — Microscopic  der  Faserstoffe,  F.  von  Hohnel,  Vienna. 
1888. — Chemische  Technologic  der  Gespinnstfasern,  Otto  Witt,  Braunschweig. 

Wool  Manufacture,  R.  Beaumont,  London. 
1890. — Les  Industries  de  la  Soie,  Sericulture,  etc.,  E.  Pariset,  Lyons. 

La  Soie,  L.  Vignon,  Paris. 

Industrie  de  la  Soie,  F.  Dehaitre,  Paris. 
1895. — Grundriss  der   Allgemeinen   Waarenkunde,   Erdman-Kb'nig,    12te   Auf.,   Von 

Hanausek,  Leipzig. 

1902. — The  Textile  Fibres  of  Commerce,  Wm.  T.  Hannan,  London  and  Philadelphia. 
1907. — Papier-prufung,  Wilhelm  Herzberg,  3te  Auf.,  J.  Springer,  Berlin. 

STATISTICS. 

Wool. — The  following  figures  show  the  production,  importation,  and 
home  consumption  of  wool  for  the  United  States  in  recent  years : 

Production.  Importation.  Home  consumption. 

Year.                                        Pounds.                        Pounds.  Pounds. 

1905  295,488,428  249,135,746  542,062,536 

1906 298,915,130  201,688,668  494,960,990 

1907  298,294,750  203,847,545  498,695,547 

1908  311,138,321  125,980,524  431,252,030 

1909  328,110,749  266,409,304  590,996,078 

(Statistical  Abstract  of  U.  S.,  1909.) 

The  importations  of  wool  during  the  last  few  years  are  thus  classified : 

1908  1909  1910 

Class  L— Clothing  wool  (Ibs.)    45,798,303  142,580,993  111,592,978 

Valued  at    $10,278,199  $29,455,598  $27,231,052 

Class  II.— Combing  wool    (Ibs.)    13,332,540  21,952,259  31,614,235 

Valued  at    $3,624,617  $4,591,559  $7,931,145 

Class  III.— Carpet  wool  (Ibs.)    66,849,681  101,876,052  120,721,019 

Valued  at    $9,762,122  $11,124,837  $16,058,647 

The  world's  production  of  raw  wool  in  1903  was  estimated  to  be  2666 
million  pounds.  The  chief  producing  country,  Australia,  exported  as 
follows : 

Raw  wool.  Scoured  wool. 

Amount  Value  in  •        Amount  Value  in 

in  1000  pds.  in  1000  pds. 

1000  Ibs.  sterling  1000  Ibs.  sterling 

1904  339,395  13,147  55,911    3,975 

1905  380,420  15,574  56,775    4,247 

1906  415,353  17,547  64,889    5,099 

1907  512,757  22,928  72,318    5,964 

1908  471,846  18,028  70,915    4,886 

(Statistical  Abstract,  1909.) 

After  the  British  Colonies  of  Australia,  New  Zealand,  and  Cape  of 
Good  Hope,  the  largest  wool  producing  country  is  the  Argentine  Republic 
and  La  Plata.  The  exports  in  bales  of  one  hundred  and  twenty-five  kilos, 
were  as  follows: 

1900  468,000  bales. 

1905  403,821  bales. 

1906  419,386  bales. 

1907  384,971  bales. 

1908  382,000  bales. 


BIBLIOGRAPHY  AND  STATISTICS. 


355 


Silk. — The  production  of  raw  silk  throughout  the  world  at  five-year 
intervals,  as  given  in  the  Census  Report  of  1905,  was: 


1885. 

1890. 

1895. 

1900. 

1905. 

Italy    (kilos)     

2,810,000 

3,033,000 

4,661,900 

4,528,500 

4,900,000 

France    (kilos)     

483,000 

618,000 

896,000 

500,000 

625,000> 

Austria    (kilos)    

142,000 

267,000 

266,000 

276,000 

315,000 

Spain    (kilos)       .  

85,000 

65,000 

90,000 

78,000 

77,000 

The  Levant    (  kilos  ) 

730,000 

707,000 

1,244,000 

1,760,000 

2,186,000 

Japan,  exports    (kilos)     . 

1,346,000 

2,130,000 

3,076,000 

3,371,000 

5,679,518 

China,  Shanghai    (kilos)  . 

2,695,000 

2,914,000 

3,358,000 

4,756,000 

2,950,047 

China,   Canton    (kilos)     . 

774,000 

1,529,000 

1,394,000 

2,253,000 

2,137,785 

India,  Calcutta   (kilos)    . 

861,000 

210,000 

199,000 

350,000 

180,000 

Total  9,926,000  11,473,000  15,184,900  17,932,000  19,050,350 

The  same  report  thus  gives  the  raw  silk  consumption  of  the  world 
by  countries,  taking  an  average  of  the  years  1902,  1903,  and  1904: 


Country.  Kilograms. 

United  States    6,128,000 

France    4,327,000 

Germany     2,846,000 

Switzerland    1,595,000 

Russia  and   Caucasus    . .  1,271,000 

Italy     966,000 

Austria-Hungary     776,000 

England    709,000 

India 350,000 

Egypt    200,000 

Spain    183,000 

Syria    110,000 

Morocco    70,000 

Algeria  and  Tunis    65,000 

Other  countries   152,000 

19,748,000 


Pounds. 
13,512,240 
9,541,035 
6,275,430 
3,516,975 
2,802,555 
2,130,030 
1,711,080 
1,563,345 

771,750 

441,000 

403,515 

242,500 

154,350 

143,325 

335,160 

43,544,340    100.0 


Per  cent,  of 
total. 

31.0 
21.9 
14.4 

8.1 

6.4 

4.9 

3.9 

3.6 

1.8 

1.0 

0.9 

0.6 

0.4 

0.3 

0.8 


No  data  exist  to  show  the  consumption  in  China  and  Japan  and  they 
are  not  included. 


The  importations  of  raw  silk  into  the  United  States  for  the  last  few 
years  have  been  as  follows : 

1905 22,357,307  pounds,  valued  at  $61,040,053 

1907    18,743,904        "  "  71,411,899 

1908    16,662,132        "  "  64,546,903 

1909    25,187,957        "  "  79,903,586 

1910   23,457,223        "  "  67,129,603 

(Commerce  and  Navigation  of  U.  S.,  1910.) 


356 


ANIMAL  TISSUES  AND  THEIR  PRODUCTS. 


FIG.  93. 


CHAPTER   X. 

ANIMAL   TISSUES   AND   THEIR  PRODUCTS. 

A.  LEATHER  INDUSTRY. 

I.  Raw  Materials. 

1.  ANIMAL  HIDES  AND  SKINS. — The  moist  animal  skin  undergoes 
decomposition  very  rapidly;  if  dried  it  becomes  stiff  and  horny,  or  if 
boiled  with  water  is  changed  into  soluble  glue.  The  object  of  tanning 
is  to  bring  the  animal  skin  into  such  a  condition  that  decomposition  is 
arrested,  and  after  drying  it  no  longer  forms  a  stiff  horny  mass,  but  an 
opaque  tissue  insoluble  in  water,  distinctly  fibrous  and  pliable.  The 
product  known  as  leather  has  properties  which  at  once  distinguish  it 
from  the  untanned  hide,  such  as  greater  or  less  impermeability  to  water 
and  toughness  and  strength.  Nevertheless,  the  best  authorities  on  the 

subject  believe  that  in  the 
main  tanning  is  a  physical 
rather  than  a  chemical  pro- 
cess, and  that  the  function  of 
the  tanning  material  is  chiefly 
to  penetrate  the  pores  of  the 
skin  and  envelop  the  indi- 
vidual fibres  so  that  in  drying 
they  are  prevented  from  ad- 
hering and  so  stiffening  the 
whole  mass.  The  power  of 
the  skins  to  fix  tanning  mate- 
rials upon  the  surface  of  its 
fibres  varies  considerably 
according  to  the  nature  of  the 
material  used,  and  in  many 
'  grades  of  leather  is  undoubt- 
edly supplemented  by  a 
chemical  combination  of  the 
coriin  of  the  skin  with  the 
tannin. 

To  understand  the  nature 

of  the  change  wrought  by  tanning  in  the  animal  hide,  it  is  necessary 
first  to  refer  briefly  to  its  anatomical  structure.  Fig.  93  shows  a  section 
of  ox-hide  cut  parallel  with  the  hair,  magnified  about  fifty  diameters. 
It  consists  essentially  of  three  layers :  the  epidermis,  which  is  itself  made 
up  of  two  layers,  the  outer  horny  layer  or  cuticle  A,  a  dead  layer  which 
is  continually  wearing  off  and  being  renewed,  and  the  inner  mucous  layer 


LEATHER  INDUSTRY.  357 

B,  the  rete  Malpighii,  a  watery  cellular  layer,  which  rests  upon  the  true 
skin  and  is  continually  renewing  the  outer  layer ;  the  derma  or  corium,  the 
true  skin,  C,  which  alone  is  the  leather-tissue;  and  the  fatty  under 
tissue,  shown  in  the  illustration  at  D,  in  which  the  perspiratory  and 
sebaceous  glands  are  embedded.  Both  the  epidermis  and  the  under 
tissue  are  removed  in  the  preparatory  processes  of  tanning,  so  that  the 
corium  alone  remains  to  combine  with  the  tanning  materials  to  form 
leather.  The  hair  of  the  animal  is  enclosed  in  hair-sheaths,  which  pass 
down  through  the  epidermis  and  rest  upon  the  corium,  from  which  in 
life  the  hair-glands  draw  their  nourishment.  The  corium,  or  true 
leather- forming  layer,  is  composed  of  bundles  of  interlacing  fibres, 
between  which  is  found  an  albuminoid  substance,  coriin,  which  as  the 
skin  dries  cements  the  fibres  together  and  stiffens  the  hide.  This  is  in- 
soluble in  water  but  soluble  in  lime-water,  and  hence  removed  in  large 
part  by  the  process  of  liming  to  which  the  hides  are  submitted. 

The  animal  skins  which  are  utilized  in  the  manufacture  of  leather 
are,  first,  those  of  the  ox,  cow,  buffalo,  horse,  etc.  These  are  known  as 
hides,  or  if  from  younger  animals  of  the  same  kind  as  kips.  Second, 
those  of  the  calf,  sheep,  goat,  deer,  etc.  These  are  known  as  skins.  For 
special  purposes  the  skins  of  crocodiles,  alligators,  porpoises,  and  seals 
are  also  made  into  leather. 

The  hides  may  come  to  the  tannery  according  to  the  source  whence 
obtained  either  as  fresh  or  green  hides, — that  is,  direct  from  the 
slaughter-houses, — as  wet  salted,  as  dry  salted,  and  as  dried  hides.  In 
addition  to  the  domestic  production,  great  numbers  of  hides  are  im- 
ported into  the  United  States  from  the  Argentine  Republic  and  the 
River  Plate  in  South  America.  England  imports  from  India,  the  Cape 
of  Good  Hope,  and  Australia  as  well  as  from  South  America.  Goat- 
skins for  the  morocco  trade  are  brought  mainly  from  India  and  the  East. 

2.  TANNIN-CONTAINING  MATERIALS. — The  conversion  of  the  hides  into 
leather  is  usually  accomplished  by  the  action  of  an  extract  or  infusion 
of  tannin  or  tannic  acid.  This  powerful  astringent  acid  is  very  widely 
distributed  in  nature,  being  found  in  barks,  roots,  leaves,  seed-pods, 
flowers,  and  fruits,  and  in  excrescences  on  trees.  More  accurately  speak- 
ing, we  find  a  number  of  varieties  of  tannic  acid  in  these  different  vege- 
table sources,  of  which  some  are  more  valuable  for  tanning  than  others. 
As  a  class  they  are  readily  soluble  in  water,  amorphous,  of  slight  acid 
reaction,  and  astringent  taste.  They  yield  with  iron  salts  bluish-black 
or  greenish  precipitates,  throw  gelatine  and  albumen  out  of  solution, 
and  change  hides  into  leather.  In  tanning  it  is  not  necessary  to  extract 
the  acid  in  a  pure  state,  but  infusions  are  made  from  the  powdered  barks 
as  needed,  or  concentrated  extracts  prepared  for  this  purpose  are  used. 
We  will  note  briefly  the  more  important  tannin-containing  materials 
used  at  the  present  time  in  leather  manufactures. 

Oak-bark. — The  common  English  oak  (Quercus  Robur],  which  in- 
cludes the  two  varieties  Q.  pedunculata  and  Q.  sessiliflora,  is  one  of  the 
most  important  materials.  It  contains  from  twelve  to  fifteen  per 
cent,  of  tannic  acid  and  produces  an  excellent  quality  of  leather.  Other 
varieties  in  use  are  Quercus  coccifera  (or  kermes-oak),  of  which  the 


358  ANIMAL  TISSUES  AND  THEIR  PRODUCTS. 

bark,  known  as  coppice-oak,  is  yellowish-brown  in  hue  and  very  rich  in 
tannin;  Quercus  suber  (or  cork-oak)  and  Quercus  Ilex  (or  evergreen- 
oak),  both  of  which  are  grown  in  Algiers,  Italy,  Spain,  and  the  South 
of  France.  In  the  United  States  the  most  important  varieties  of  oak  are 
Quercus  prinus  or  castanea  (chestnut-oak)  ;  Quercus  rubra  (common 
red-oak);  Quercus  alba  (or  white-oak).  The  tannin  of  the  several 
varieties  of  oak  is  known  as  quercitannic  acid.  According  to  the  re- 
searches of  Etti,*  the  main  constituents  of  the  oak-bark  are  quercitannic 
acid,  with  the  formula  C17H16O9;  its  first  anhydride,  phlobaphene, 
C34H30017;  its  second  anhydride,  C34H28016;  its  third  anhydride,  Oser's 
oak-red,  C34H26O15;  and  its  fourth  anhydride,  Lowe's  oak-red,  C34H24014. 
Of  these,  the  quercitannic  acid  and  the  phlobaphene  are  specially  con- 
cerned in  the  tanning  process. 

Hemlock-bark. — The  bark  of  the  hemlock  (Abies  Canadensis)  of 
Canada  and  the  United  States  contains  nearly  fourteen  per  cent,  of 
tannin.  This  is  extensively  used,  either  jointly  with  oak-bark  (union 
tanned  leather)  or  as  a  substitute  for  it,  in  the  manufacture  of  sole- 
leather.  It  is  said  to  produce  a  harder  leather  than  oak-bark,  but  less 
pliable  and  more  pervious  to  water.  A  solid  extract  from  the  hemlock- 
bark  containing  from  twenty-five  to  thirty-five  per  cent,  of  a  deep  red 
tannin  is  prepared  in  large  quantities  for  export.  The  production  of 
this  solid  extract  is  said  to  be  at  present  considerably  over  ten  thousand 
tons  per  annum.  Liquid  extracts  with  fifty  per  cent,  of  solid  matter  are 
also  largely  sold. 

Pine-bark  is  much  used  in  Austria,  Bavaria,  and  Southern  Germany. 
It  contains  from  seven  to  ten  per  cent,  of  tannin  and  considerable  resin- 
ous extractive  matter.  It  does  not  yield  so  good  a  leather  as  oak-bark. 

Closely  related  and  somewhat  used  are  the  barks  of  the  White  Spruce, 
the  Larch,  and  the  Fir. 

Willow-bark. — Several  species  of  the  willow,  notably  Salix  arenaria 
and  8.  caproza,  are  used  in  Russia  and  Denmark  for  the  tanning  of  lighter 
skins,  for  the  manufacture  of  glove  leather  and  the  so-called  Russia 
leather.  It  is  stated  that  the  yearly  consumption  of  willow-bark  in 
Russia  at  present  is  some  six  and  a  half  million  kilos,  against  two  and  a 
half  million  kilos,  of  all  other  tanning  barks.  The  percentage  of  tannin 
in  the  willow  is  usually  given  at  from  three  to  five  per  cent.,  although 
Eitner  f  found  over  twelve  per  cent,  in  several  species. 

Chestnut-wood. — The  wood  of  the  chestnut  (Castanea  vesca)  contains 
from  eight  to  ten  per  cent,  of  a  tannin  which  closely  resembles  gallo- 
tannic  acid.  The  extract,  containing  from  fourteen  to  twenty  per  cent, 
of  tannin,  is  used  largely  to  modify  the  color  produced  by  hemlock 
extract  and  for  tanning  and  dyeing.  > 

Horsechestnut-bark. — The  bark  of  the  horsechestnut  (^Esculus  hippo- 
cast anum)  is  also  said  to  be  used  for  the  manufacture  of  an  extract 
under  the  simple  name  of  "chestnut  extract,"  but  such  manufacture  in 
the  United  States  is  very  doubtful. 

*  Wagner's  Chemical  Technology,  13th  ed.,  p.  1051. 
t  V.  Hohnel,  Die  Gerbriende,  p.  90. 


LEATHER  INDUSTRY.  359 

Catechu  (or  Cutch)  is  the  name  given  the  dried  extract  from  Acacia 
Catechu,  cultivated  in  India  and  Burmah,  and  containing  forty-five  to 
fifty-five  per  cent,  of  a  special  variety  of  tannic  acid  (catechu  or  mimo- 
tannic).  The  extract  is  evaporated  until  a  semi-solid  dark-brown  pro- 
duct is  obtained.  This  is  exported  in  mats,  bags,  and  boxes  to  European 
and  American  markets. 

Gambier  or  Gambir  (Pale  Catechu)  is  the  dried  extract  from  the 
leaves  of  Uncaria  Gambler  and  U.  acida.  It  contains  thirty-six  to  forty 
per  cent,  of  a  brown  tannin  which  rapidly  penetrates  leather  and  tends 
to  swell  it,  but  taken  alone  produces  a  soft,  porous  tannage ;  it  is  largely 
used  in  conjunction  with  other  materials  for  tanning  both  light  and 
heavy  leathers.  It  is  exported  from  Singapore  in  pressed  blocks  and 
cubes.  The  catechutannic  acids  of  cutch  and  gambier  differ  from  gallo- 
tannic  acid  in  giving  a  grayish-green  precipitate  with  ferric  salt  and 
no  reaction  with  ferrous  salts ;  by  giving  a  dense  precipitate  with  cupric 
sulphate  and  none  with  tartar  emetic.  They  also  contain  catechin, 
which  is  said  to  be  an  anhydride  of  catechutannic  acid. 

Kino  is  an  extract  somewhat  resembling  cutch,  and  is  the  dried  juice 
from  a  variety  of  plants.  Thus,  the  East  Indian  kino  is  obtained  from 
Ptcrocarpus  marsupium,  the  Bengal  kino  from  Butea  frondosa,  the 
African  from  Pterocarpus  erinaceum,  and  the  Australian  from  the 
several  species  of  Eucalyptus.  It  ordinarily  forms  small  angular  frag- 
ments of  black  lustrous  appearance,  brittle,  and  crumbling  to  brown-red 
powder.  It  contains  thirty  to  forty  per  cent,  of  a  tannin  (kinotannic 
acid)  analogous  to  catechutannic  acid,  together  with  phlobaphene. 

Sumach  consists  of  the  powdered  leaves,  peduncles,  and  young 
branches  of  Rhus  coriaria,  Rhus  cotinus,  and  other  species  of  Rhus. 
Thus,  Sicilian  sumach,  the  most  esteemed  variety,  is  from  R.  coriaria; 
Spanish  sumach  is  from  several  species  of  Rhus,  and  comes  in  three 
varieties,  Malaga,  Molina,  Valladolid ;  Tyrolean  sumach  from  R.  cotinus; 
French  from  Coriaria  myrti folia;  American  from  R.  glabra,  R.  Cana- 
dense,  and  R.  copallina.  The  leaves  are  collected  while  the  shrub  is  in 
full  foliage  and  cured  by  drying  in  the  sun.  They  are  then  ground 
under  millstones  and  the  product  baled.  The  sumach  contains  from 
sixteen  to  twenty-four  per  cent,  of  a  tannin  which  seems  to  be  identical 
with  gallotannic  acid.  The  American  variety  contains  usually  six  to 
eight  per  cent,  more  than  the  European,  but  also  contains  more  of  a 
dark  coloring  matter,  which  renders  it  inferior  to  the  Sicilian  sumach 
for  white  leathers. 

Myrobalans  (or  Myrabolans). — The  fruit  of  several  species  of  Termi- 
nalia  found  in  Hindostan,  Ceylon,  Burmah,  etc.  Myrobalans  varies  in 
size  from  that  of  a  small  hazel-nut  to  that  of  the  nutmeg.  The  tannin 
occurs  in  the  pulp  which  surrounds  the  kernel.  It  is  generally  used  in 
combination  with  other  tanning  materials  to  modify  the  objectionable 
color  wrhich  some  of  the  latter  impart  to  the  leather.  By  itself  it  pro- 
duces a  soft  and  porous  tannage. 

Valonia  is  the  commercial  name  for  the  acorn  cups  of  several  species 
of  oak,  Quercus  cegilops  and  Quercus  macrolepis,  coming  from  Asia 


360  ANIMAL  TISSUES  AND  THEIR  PRODUCTS. 

Minor,  Roumelia,  and  Greece.  They  are  of  a  bright-drab  color,  and 
contain  twenty-five  to  thirty-five  per  cent,  of  a  tannin  somewhat  resem- 
bling that  of  oak-bark,  but  giving  a  browner  color  and  heavier  bloom. 
It  is  generally  used  in  admixture  with  oak-bark,  myrobalans,  or  mimosa- 
bark,  because  of  itself  it  produces  too  brittle  a  leather. 

Mimosa-bark  (Wattle). — The  bark  of  numerous  species  of  Acacia 
(A.  decurrens  and  A.  dealbata)  from  Australia  and  Tasmania,  contains 
from  twenty-four  to  thirty  per  cent,  of  mimotannic  acid.  The  bark 
comes  into  commerce  chopped  or  ground  and  also  in  the  form  of  an 
extract.  It  makes  a  red  leather  and  is  generally  used  in  admixture. 

Divi-divi. — The  seed-pods  of  Ccesqlpinia  Coriaria,  a  small  tree  found 
in  the  neighborhood  of  Maracaibo,  South  America.  The  pods  are  about 
three  inches  long,  brownish  in  color,  and  generally  bent  by  drying  into 
the  shape  of  the  letter  S.  It  contains  thirty  to  fifty  per  cent,  of  a  pecu- 
liar tannin  somewhat  similar  to  that  of  valonia,  but  is  liable  to  fermen- 
tation. 

Quebracho. — This  is  the  name  applied  to  several  South  American 
trees  possessing  hard  wood.  They  are  Aspidosperma  Quebracho  (Que- 
bracho bianco),  Loxopterygium  Lorentzii  (Quebracho  Colorado).  The 
wood  and  bark  of  the  latter  contain  from  fifteen  to  twenty-three  per 
cent,  of  a  bright  red  tannin.  Both  the  wood  and  the  extract  are  used  in 
tanning. 

Nutgalls  is  the  term  applied  to  the  excrescences  on  plants  produced 
by  the  punctures  of  insects  for  the  purpose  of  depositing  their  eggs.  The 
principal  commercial  kinds  are  oak-galls  (or  Aleppo  galls)  and  Chinese 
galls.  The  first  of  these  are  the  product  of  the  female  of  an  insect  called 
Cynips,  which  pierces  the  buds  on  the  young  branches  of  the  Quercus 
infectoria  and  other  species  of  oak.  In  the  centre  of  the  gall  thus  pro- 
duced the  larva  is  hatched  and  undergoes  its  transformation,  boring  its 
way  out  as  a  winged  insect  in  five  to  six  months.  If  the  galls  are  gath- 
ered while  the  insect  is  in  the  larval  state  they  are  known  as  "blue"  or 
"green"  galls;  if  the  insect  has  cut  its  way  out  they  are  known  as 
"white"  galls,  and  are  of  inferior  character  and  less  astringent.  The 
best  oak-galls  contain  from  sixty  to  seventy  per  cent,  of  gallotannic  acid. 

The  Chinese  gallnuts  are  the  product  from  the  Rhus  semialata,  the 
leaves  of  which  are  punctured  by  an  insect,  the  Aphis  Chinensis.  The 
nuts  are  of  irregular  shape  but  are  very  rich  in  tannin,  containing 
about  seventy  per  cent. 

Knoppern  are  galls  from  immature  acorns  of  several  species  of  oak 
largely  used  for  tanning  in  Austria.  They  contain  from  twenty-eight 
to  thirty-five  per  cent,  of  tannin. 

> 
n.  Processes  of  Manufacture. 

Leather  may  be  manufactured  from  hides  or  skins  by  a  number  of 
methods,  which  may  be  summarized,  however,  under  three  heads, — viz., 
tanning  by  the  use  of  tannin-containing  barks  or  extracts;  mineral  tan- 
ning, using  either  chromium  salts  to  make  an  insoluble  leather,  or  alum 


LEATHER  INDUSTRY.  361 

and  salt,  as  in  "tawing;"  and  the  manufacture  of  soft  leather  by  treat- 
ment of  the  skins  with  oils. 

We  will  note  first  the  methods  involving  the  use  of  tannin-contain- 
ing materials,  and  these  again  differ  somewhat  according  to  the  grade 
of  leather  to  be  made  and  the  character  of  the  hides  or  skins  used. 

A.  MANUFACTURE  OF  SOLE-LEATHER. — 1.  Softening  and  Cleansing 
the  Hides. — This  process  differs  according  as  the  hides  are  taken  in  the 
fresh  or  green  state  or  are  salted  or  dried.  For  fresh  hides,  a  washing 
with  pure  water  to  cleanse  them  from  dirt  and  blood  is  all  that  is  neces- 
sary to  prepare  them  for  the  next  or  "swelling"  process.  For  salted 
hides,  a  soaking  in  fresh  water  for  from  two  to  three  days  is  necessary, 
while  for  hard  dried  hides  a  longer  treatment  is  necessary,  first  in  water 
which  has  been  repeatedly  used  for  softening  and  afterwards  in  fresh 
water.  This  involves  often  a  slight  putrefaction  of  the  coagulated  albu- 
men of  the  dry  hide.  To  control  this  and  prevent  injury  to  the  corium 
of  the  hide  a  weak  salt  solution  (five  per  cent.)  is  often  used  in  this  pro- 
longed softening.  "Stocking"  or  kneading  the  hides  with  heavy  rolls 
or  breaking  weights  is  also  needed  for  heavy  hides  which  have  been  dried. 

2.  Unhairing  and  Swelling. — These  operations  are  carried  out  to- 
gether. As  the  swelling  proceeds  the  cells  in  which  the  roots  of  the  hair 
are  embedded  are  softened,  so  that  the  hair  is  easily  removed  by  mechan- 
ical means.  The  horny  epidermis  is  similarly  softened,  so  that  it  can  be 
removed  by  the  same  means.  The  swelling  may  be  effected  by  several 
different  methods:  (1)  by  sweating;  (2)  by  treatment  with  acid  tan- 
liquor;  (3)  by  liming;  (4)  by  treatment  with  sulphides  of  sodium  and 
calcium,  etc.  The  sweating  process  now  in  use  is  the  so-called  "cold 
sweating"  method,  and  consists  in  hanging  the  hides  in  a  moist  cham- 
ber kept  at  a  uniform  temperature  of  60°  to  70°  F.  (15°  to  21°  C.),  so 
that  an  incipient  putrefaction  ensues  which  attacks  the  soft  parts  of  the 
epidermis  and  root-sheaths  before  materially  injuring  the  corium  or 
leather-forming  material.  This  method  is  that  generally  followed  for 
sole-leather  in  this  country  and  on  the  Continent  of  Europe,  while  in 
England  liming  is  more  generally  adopted.  The  swelling  with  acid  tan- 
liquor  depends  upon  the  action  of  the  acids  which  are  present  in  con- 
siderable quantity  in  old  tan-liquors  and  their  effect  upon  the  connective 
tissue.  The  swelling  and  unhairing  by  lime  always  adopted  for  small 
skins  is  also  used  for  sole-leather  hides  in  England.  A  view  of  the  lime- 
pits  and  skins  in  process  of  softening  by  lime  as  carried  out  in  morocco 
tanneries  is  shown  in  Fig.  94.  The  action  of  the  lime  upon  the  hide  is 
in  part  a  solvent  one.  The  hair-sheaths  are  loosened  and  dissolved  and 
the  hardened  epidermis  swells  up  and  softens,  so  that  both  come  away 
more  or  less  completely  with  the  hair  when  scraped.  The  intercellular 
substance,  or  coriin,  as  before  stated,  is  also  soluble  in  the  lime-water, 
and  as  this  is  removed  the  fibrous  nature  of  the  leather-forming  skin 
becomes  more  evident.  The  hides  are  generally  put  into  several  lime- 
pits  in  succession,  in  the  first  of  which  is  old  liquor  with  the  weakest 
alkaline  reaction  because  of  its  partial  saturation  with  organic  material, 
and  in  the  last  the  liquor  is  the  freshest  and  strongest  in  alkaline  reac- 


362 


ANIMAL  TISSUES  AND  THEIR  PRODUCTS. 


FIG.  94. 


LEATHER  INDUSTRY.  363 

tion.  The  hides  require  to  be  turned  and  changed  in  position  during  this 
liming  process  as  well  as  removed  from  one  pit  to  the  other.  The  swell- 
ing and  unhairing  by  the  use  of  alkaline  sulphides  largely  used  upon  the 
Continent  of  Europe  consists  in  taking  a  solution  of  sodium  sulphide 
(made  from  alkali- waste  by  Schaffner  and  Helbig's  process)  and  bring- 
ing it  to  a  thin  pasty  condition  with  lime.  This  is  then  spread  upon  the 
hair  side  of  the  hides  and  they  are  packed  together  for  five  to  twenty 
hours,  when  the  loosened  hair  and  sulphide  paste  are  washed  off  and 
the  hides  left  in  water  a  time  longer  to  "plump"  or  swell.  Another 
process  uses  the  sulphide  in  solution  only.  The  hair  having  been  loosened 
by  one  or  the  other  of  the  means  just  described,  it  is  to  be  removed  by 
mechanical  means.  This  is  usually  done  on  the  ' '  beam, ' '  a  sloping  frame 
of  wood  or  metal,  with  a  blunt  two-handled  knife,  which  pushes  the  hair 
downward  and  away  from  the  workman.  After  the  unhairing,  the  loose 
flesh  and  fat,  the  latter  somewhat  saponified  by  the  lime,  are  next 
removed  from  the  inner  side  of  the  hide  by  a  sharp-edged  knife.  Hand 
"fleshing"  is  in  many  cases  superseded  by  machine  treatment,  as  the 
hide  must  not  only  be  scraped  but  worked  to  force  out  the  fat  which 
remains  in  the  loose  tissue,  as  this  would  impede  tanning.  The  hides 
after  the  fleshing  are  trimmed,  and  the  inferior  ends  and  edges  are  cut 
off  with  a  sharp  knife.  They  have  still  to  be  freed  from  the  traces  of 
lime  which  they  have  absorbed  during  the  lime  treatment  before  they 
can  be  put  in  the  tan-liquors.  This  used  to  be  done  for  sole-leathers, 
as  it  is  still  done  for  calf-  and  goat-skins,  by  means  of  ' '  bate. ' '  or  dung 
of  animals,  mixed  with  water,  but  that  is  now  almost  entirely  replaced 
by  the  use  of  dilute  acids  which  shall  combine  with  the  lime,  when  the 
lime  salts  so  formed  are  to  be  washed  out.  Dilute  sulphuric,  phosphoric, 
and  hydrochloric  acids  have  been  used  (the  latter  being  best  because  its 
lime  salt  is  soluble),  as  well  as  the  acid  tan-liquors  containing  gallic, 
acetic,  and  lactic  acids.  The  organic  acids  are  considered  to  be  safer 
for  the  hide  than  the  inorganic. 

3.  Tanning. — The  bark  or  other  tanning  material  must  be  crushed 
and  then  ground  to  a  state  sufficiently  fine  to  allow  of  the  extraction  of 
the  tannic  acid,  and  yet  not  so  fine  as  to  cause  it  to  cake  together  in 
clayey  masses.  This  is  accomplished  in  bark-mills  and  disintegrators  of 
various  kinds,  which  need  not  be  specially  described  here.  The  tan- 
house  into  which  the  cleansed  and  prepared  hides  or  "butts"  now  come 
is  provided  with  rows  of  pits  running  in  parallel  lines,  which  are  to 
contain  the  butts  during  the  treatment  with  the  tan-liquor.  The  butts 
in  most  cases  are  first  suspended  in  weak  tanning  infusions  before  they 
go  into  the  first,  or  "handler,"  pits.  The  object  of  this  is  to  insure  the 
uniform  absorption  of  tannin  by  the  skins  before  subjecting  them  to 
the  rough  usage  of  "handling,"  which  in  the  early  stages  of  the  process 
is  liable  to  cause  injury  to  the  delicate  structure  of  the  skin.  During 
this  suspension  the  skins  should  be  in  continuous  agitation  to  cause  the 
tannin  to  be  taken  up  evenly.  Both  the  suspension  and  the  agitation 
are  accomplished  generally  by  mechanical  means.  From  the  suspenders 
the  butts  are  transferred  to  the  "handlers,"  where  they  are  laid  flat  in 


364 


ANIMAL  TISSUES  AND  THEIR  PRODUCTS. 


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LEATHER  INDUSTRY.  365 

the  liquor.  They  are  here  treated  with  weak  infusion  of  bark,  com- 
mencing at  about  15°  to  20°  by  the  barkometer,  and  are  handled 
twice  a  day  during  the  first  two  or  three  days.  This  may  be  done 
by  taking  them  out,  turning  them  over,  and  returning  them  to  the 
same  pit,  or  more  generally  by  running  them,  fastened  together,  from 
one  handler-pit  into  another.  The  treatment  of  the  butts  in  the  handlers 
generally  occupies  about  six  to  eight  weeks,  by  which  time  the  coloring 
matter  of  the  bark  and  the  tannin  should  have  "struck"  through  about 
one-third  of  the  substance  of  the  skin.  Many  of  the  butts  will  have 
become  covered,  moreover,  with  a  peculiar  "bloom"  (ellagic  acid)  in- 
soluble in  water.  They  are  now  removed  to  the  "layers,"  in  which  they 
receive  the  treatment  of  bark  and  "ooze,"  or  tan-liquor,  in  progressive 
stages  until  the  tanning  is  complete.  Here  the  butts  are  stratified  with 
ground  oak-bark  or  valonia,  which  is  spread  upon  each  butt  to  the 
depth  of  about  one  inch,  and  a  thicker  layer  finally  on  top.  The  pit  is 
then  filled  up  with  ooze,  which  varies  in  strength  from  about  35°  barko- 
meter at  the  beginning  to  70°  at  the  end  of  the  treatment.  For  heavy 
tannages  six  to  eight  layers  are  required,  the  duration  of  each  ranging 
from  ten  days  at  the  beginning  to  a  month  in  the  later  stages.  Each  time 
the  butts  are  raised  they  should  be  mopped  on  the  grain  to  remove  dirt 
and  loose  bloom. 

With  the  use  of  strong  prepared  extracts,  especially  with  the  aid  of 
heat,  the  tanning  process  can  be  carried  out  in  much  shorter  time  than 
that  just  indicated,  but  the  leather  produced  though  hard  is  deficient  in 
toughness  and  is  liable  to  crack  on  bending  sharply. 

4.  Finishing. — The  butts  after  coming  from  the  last  layer  are  well 
brushed,  washed  in  a  clear  liquor,  and  then  thrown  over  a  "horse"  to 
drain  before  going  to  the  drying-shed.  They  are  then  frequently  oiled 
lightly  on  the  grain  so  as  to  prevent  too  rapid  drying  out  and  hung  on 
poles  in  the  drying-loft.  When  about  half  dry,  they  are  heaped  upon  the 
floor  in  piles  and  covered  to  sweat  a  little,  which  facilitates  the  operation 
of  ' '  striking, ' '  which  next  follows. 

The  "striking,"  which  may  be  done  by  hand  with  a  two-handled  tool 
with  triangular  blunt  edges  or  by  machinery,  is  chiefly  for  the  purpose 
of  removing  the  deposit  called  bloom,  although  it  somewhat  flattens  and 
stretches  the  leather.  After  a  little  further  drying  the  butt  is  laid  upon 
a  flat  bed  of  wood  or  metal  and  is  rolled  either  by  heavy  hand-rollers 
or  by  the  aid  of  machinery.  The  leather  is  then  sometimes  colored  on 
the  grain  with  a  mixture  of  yellow  ochre,  with  size  and  oil  to  give  a 
gloss,  and  then  brushed  again,  well  rolled,  and  dried  off  gradually  in  a 
room  slightly  warmed  by  steam.  The  main  outlines  of  sole-leather  tan- 
ning are  summarized  on  the  accompanying  diagram. 

B.  UPPER  AND  HARNESS  LEATHERS. — For  upper  and  harness  leathers 
the  hides  of  cows  and  smaller  oxen  are  chosen.  Fresh  hides  are,  more- 
over, much  better  adapted  for  this  class  of  leathers  than  dry  salted  or 
dry  "flint"  hides,  as  the  utmost  toughness  and  strength  rather  than 
hardness  or  weight  are  to  be  secured.  The  hides  are  cleansed,  limed, 
and  unhaired  very  much  as  already  described  for  sole-leather.  They  are 


366 


ANIMAL  TISSUES  AND  THEIR  PRODUCTS. 
FIG.  95. 


LEATHER  INDUSTRY.  367 

then  "bated"  in  a  bate  of  hen  manure  or  treated  with  sour  bran-liquor 
to  completely  remove  the  lime  from  the  pores  of  the  skin.  The  remain- 
ing portions  of  hair-sheaths  and  fat-glands  are  at  the  same  time  so 
loosened  that  they  are  easily  worked  out  by  a  blunt  knife  on  the  beam. 
This  final  cleansing  process  is  called  "scudding."  The  action  of  the 
"bate"  is  considered  by  the  best  authorities  to  be  a  fermentative  one, 
and  the  weak  organic  acids  produced  neutralize  and  remove  the  lime 
and  at  the  same  time  soften  the  hide  by  dissolving  out  the  coriin  and 
probably  also  portions  of  the  gelatinous  fibre.  "Stocking"  is  also  used 
to  assist  in  the  softening  and  cleansing.  These  lighter  tannages  are  also 
carried  out  very  largely  by  the  aid  of  gambier  in  combination  with  bark, 
valonia,  mimosa,  and  myrobalans.  The  tanning  liquors  are  often  used 
at  temperatures  of  from  110°  to  140°  F.  (43°  to  60°  C.).  The  finishing 
of  the  light  leathers  requires  much  care  in  order  to  give  them  the  proper 
softness  and  strength.  They  are  alternately  worked  with  a  stretching- 
iron,  or  "sleeker,"  and  rubbed  with  oil  or  with  a  mixture  of  degras 
and  tallow. 

C.  MOROCCO   LEATHER. — This    is    generally    made    from    goat-skins, 
although  a  cheaper  variety  is  made  from  sheep-skins.     The  skins  are 
softened  and  then  unhaired  by  lime,  to  which  a  small  quantity  of  arsenic 
sulphide  is  often  added,  whereby  calcium  sulphydrate  and  sulpharsenite 
are  produced,  which  assist  in  softening  the  hair-sheaths  and  in  giving 
the  grain  a  higher  gloss.    A  view  of  the  unhairing  machines  and  washing 
drums  of  a  morocco  tannery  is  given  in  Fig.  95.     They  are  then  bated 
with  a  mixture  of  dog's  dung  and  water,  known  as  the  "puer."    This 
is  often  followed  by  a  treatment  with  bran  to  aid  in  removing  the  lime 
from  the  skins.     A  "scudding"  or  scraping  with  a  blunt  two-handled 
knife  on  both  the  grain  and  flesh  sides  then  ensues  to  remove  the  last 
portions  of  lime  salts  and  albuminoid  matters.     The  tanning  was  for- 
merly done  with  sumach  and  gambier,  either  in  revolving  paddle  "tum- 
blers," as  shown  in  Fig.  96,  or  according  to  the  English  method,  by 
sewing  up  the  skins  into  bags  partially  filled  with  the  sumach-liquor  and 
then  distended  by  air  and  floated  in  a  large  vessel  of  the  same  liquor. 
The  bags  are  turned  over  constantly,  and  afterwards  piled  up  in  heaps. 
The  sumach  solution  is  thus  forced  through  the  pores  of  the  skin,  and 
the  tanning  is  rapidly  effected.    The  tanned  skins  are  thoroughly  washed 
and  "struck,"  or  scraped  and  rubbed,  until  smooth.     After  thorough 
drying  they  are  again  struck  until  thoroughly  soft  and  smooth.     This 
sumach  tannage  has  been  replaced  in  this  country  almost  entirely  by  the 
chrome  tanning,  to  be  mentioned  later. 

D.  MINERAL  TANNING  OR  "TAWING." — Skins  may  be  converted  into 
a  substance  resembling  leather,   although  in  fact  essentially  different 
from  it,  by  the  action  of  alum  and  salt.     There  has  been  no  chemical 
combination,  however,  analogous  to  that  formed  by  the  gelatine  and 
tannic  acid  in  the  ordinary  tanning  processes,  as  the  gelatine,  alum,  and 
salt  can  be  again  separated  by  treatment  with  water. 

The  process  of  tawing  is  applied  to  goat,  kid,  sheep,  and  other  small 
skins.     The  preliminary  operations  of  steeping,  breaking,  liming,  un- 


368 


ANIMAL  TISSUES  AND  THEIR  PRODUCTS. 


hairing,  and  fleshing,  steeping  in  bran-water  and  working  on  the  beam, 
are  essentially  the  same  as  have  been  described  already.  The  skins  with 
the  pores  cleared  of  lime  and  sufficiently  opened  are  then  put  into  a  kind 
of  wooden  drum  or  "tumbler,"  such  as  is  used  for  washing  skins  and 
for  treating  morocco  leather  skins  with  sumach  solution.  For  every 
two  hundred  skins  some  twelve  pounds  of  alum  and  two.  and  a  half 
pounds  of  salt  with  twelve  gallons  of  water  are  used. 

The  action  is  continued  for  a  short  time  only, — about  five  minutes. 
They  are  then  put  into  an  emulsion  of  yolk  of  eggs  with  flour  and  water, 
and  tramped  and  worked  in  this  until  it  has  been  thoroughly  absorbed. 
The  skins  are  now  hung  upon  poles  to  dry,  after  which  they  are  stretched 
and  softened  by  drawing  them  to  and  fro  upon  the  "stake,"  a  blunt 
steel  blade  set  in  upright  position. 

FIG.  96. 


"Combination  tanning,"  in  which  the  joint  action  of  gambier  and 
alum  is  used,  is  also  extensively  followed. 

Very  different  from  this  kind  of  mineral  tanning  is  that  introduced 
within  the  last  few  years  under  the  name  of  "chrome  tanning."  It 
depends  upon  the  power  of  chromium  oxide  (sesquioxide  of  chromium) 
of  forming  an  insoluble  compound  with  the  gelatigenous  fibre  of  the 
hide,  furnishing  a  product  which  possesses  in  a  high  degree  the  water- 
proof character  desirable  for  leather. 

The  process  generally  in  use  at  present  in  this  country  involves  treat- 
ing the  skins  at  first  with  a  weak  solution  of  bichromate  of  potash  to 
which  sufficient  hydrochloric  acid  is  added  to  liberate  the  chromic  acid 
(of  course  pickled  skins  may  be  used  without  the  necessity  of  adding 
free  acid).  After  the  skins  have  taken  up  a  bright  yellow  color  through 
their  entire  texture  they  are  drained  and  transferred  to  a  bath  of  sodium 
thiosulphate,  to  which  some  acid  is  added  to  liberate  sulphurous  acid, 
which  reduces  the  chromic  acid  to  green  chromic  oxide.  The  sulphur- 
ous acid  is  at  the  same  time  oxidized  to  sulphuric  acid,  which  liberates  a 


LEATHER  INDUSTRY.  369 

further  portion  of  sulphurous  acid,  until  the  whole  of  the  chromic  acid 
is  reduced.  Hydrogen  sulphide  liberated  from  alkaline  sulphides  has 
also  been  used  as  the  reducing  agent  for  bichromated  skins,  and  still 
more  recently  electrolytic  hydrogen  developed  upon  the  bichromated 
skin  itself.  In  any  case  the  reduction  must  take  place  rapidly,  so  that 
the  potassium  bichromate  may  be  reduced  superficially  before  it  can 
"bleed"  or  diffuse  out  of  the  skins  into  the  water  of  the  reducing  bath. 

The  leather  so  produced  is  of  a  pale  bluish-green  color,  tough  and 
flexible,  and  thoroughly  resistant  to  water.  Indeed,  it  is  this  latter 
property  which  distinguishes  it  from  all  other  forms  of  leather,  as  the 
combination  of  the  hide  fibre  or  coriin  with  the  chromium  oxide  is 
apparently  more  stable  than  its  combination  with  tannin  and  yields 
less  to  boiling  water,  as  has  been  shown  in  tests  made  by  Professor  Henry 
Procter,  of  Leeds.  The  leather  can  also  be  dyed  and  produced  in  a  variety 
of  colors,  but  the  dyeing  must  be  done  before  the  leather  dries,  as  its 
water-repellent  character  is  such  that  once  dried  it  cannot  be  wetted 
sufficiently  to  take  up  a  full  color. 

Chrome-tanning  processes  involving  the  use  of  chrome  alum  and 
other  salts  of  the  sesquioxide  of  chromium  as  the  basis  of  the  tanning  vat 
have  been  used,  but  apparently  the  combination  does  not  take  place  so 
readily  as  where  the  chromium  oxide  is  obtained  in  statu  nascendi  by 
reduction  from  the  bichromate  under  the  influence  of  reducing  agents. 
Basic  chromium  salts,  such  as  the  basic  chromium  chloride,  have  also 
been  proposed  as  mineral  tanning  agents,  it  being  claimed  that  the  dis- 
solved chromium  oxide  is  taken  up  by  the  hide-fibre  at  once  and  that  a 
single  bath  only  is  necessary  in  this  case.  Such  a  basic  salt  is  prepared 
by  dissolving  commercial  chromium  hydroxide  (chrome  green)  in  hydro- 
chloric acid,  adding  sal  soda  until  precipitation  of  the  hydrate  begins 
again.  The  solution  is  then  nearly  neutral,  and  contains  an  oxychloride 
or  basic  chloride  in  solution.  Common  salt  is  also  added  to  prevent 
injury  to  the  grain  of  the  leather  and  to  facilitate  tanning.  After  the 
absorption  of  the  chromium  oxide  is  completed  the  skins  are  agitated 
in  water  containing  suspended  carbonate  of  lime  to  neutralize  all  traces 
of  acid.  They  are  then  washed  and  are  ready  for  the  fat  liquor.  At  the 
present  time  the  bulk  of  the  glazed  kid  made  in  the  United  States  is 
chrome-tanned,  two  establishments  in  Philadelphia  each  turning  out  at 
present  three  thousand  dozen  chrome-tanned  goat-skins  daily. 

Quite  recently  formaldehyde,  applied  either  as  gas  or  in  aqueous 
solution,  has  been  introduced  as  a  tanning  agent,  the  well-known  coagu- 
lating power  of  the  formaldehyde  on  animal  tissue  causing  it  to  unite 
with  the  hide  fibre  to  form  an  insoluble  leather.  All  grades  of  leather, 
from  sole  leather  to  light  morocco,  it  is  asserted,  can  be  made  readily 
and  very  rapidly  by  this  treatment.  As  yet,  it  is  too  early  to  judge  con- 
clusively of  its  quality  and  durability. 

E.  CHAMOIS  AND  OIL-TANNED  LEATHER. — The  skins  tanned  in  this 
way  are  sheep-  and  calf-skins,  and  formerly  chamois-  and  deer-skins. 
The  flesh  splints  of  sheep-skins  are  now  generally  employed  for  ordinary- 
wash-leather.  If  heavy  hides  are  taken,  the  grain  side  of  the  skin  is 

24 


370  ANIMAL  TISSUES  AND  THEIR  PRODUCTS. 

shaved  so  that  the  oil  can  penetrate  easily.  The  skins  receive  a  thorough 
liming,  so  that  the  coriin  is  thoroughly  removed  from  between  the  fibres, 
making  them  very  soft.  A  bran-drench  follows  to  remove  the  lime,  and 
they  are  worked  on  the  beam.  The  surplus  water  having  been  removed 
by  pressing,  while  still  moist  they  are  oiled  with  fish,  seal,  or  whale  oil 
(to  which  some  five  per  cent,  of  carbolic  acid  is  often  added).  After 
being  stocked  for  two  to  three  hours,  shaken  out,  and  hung  up  for  one- 
half  of  an  hour  to  an  hour  to  partially  dry,  they  are  again  oiled  and 
stocked,  and  this  process  is  repeated  until  the  skins  lose  their  original 
smell  of  limed  hide  and  acquire  a  peculiar  mustard-like  odor.  The  later 
dryings  are  frequently  conducted  in  a  heated  room,  and  when  the  oiling 
is  complete  the  skins  are  piled  up,  and  the  oxidation  of  the  oil  which  has 
already  commenced  during  the  fulling  and  drying  is  completed  by  a 
sort  of  a  fermentation,  in  which  the  skins  heat  considerably.  This  heat- 
ing must  be  controlled  so  that  the  leather  is  not  injured,  and  if  necessary 
the  pile  of  skins  is  turned.  When  the  oxidation  is  complete  the  skins 
are  of  the  yellow  chamois  leather  color.  To  remove  the  surplus  oil,  the 
skins  are  again  oiled,  then  thrown  into  hot  water  and  wrung  out.  The 
semi-solid  fat  obtained  this  way  is  the  degras  so  much  prized  for  currying 
purposes.  Or  the  whole  of  the  uncombined  oil  is  removed  by  washing 
with  soda  or  potash  lye  and  then  set  free  by  neutralizing  with  sulphuric 
acid.  The  oil  so  obtained  forms  the  "sod  oil"  of  commerce.  About 
half  of  the  oil  employed  is  retained  by  the  skin,  and  cannot  be  removed 
even  by  boiling  with  alkalies.  No  gelatine  is  obtained  by  boiling  with 
water,  to  which  the  chamoised  skin  is  much  more  resistant  than  ordinary 
leather.  The  skins  intended  for  gloves,  etc.,  are  bleached  like  linen,  by 
sprinkling  and  exposure  to  the  sun  or  with  weak  solution  of  potassium 
permanganate  followed  by  sulphurous  acid. 

HI.  Products. 

1.  SOLE-LEATHER. — This  is  the  heaviest  and  firmest  variety  of  leather 
produced.    It  is  made  from  the  heaviest  and  thickest  hides,  and  is  valued 
for  its  fine  grain  and  toughness.     It  retains  the  whole  thickness  of  the 
hide,  and  no  part  is  split  off,  so  that  it  is  not  weakened  by  the  loss  of  the 
flesh  side.    The  tanning  process  is  protracted  until  the  whole  hide  is  of 
uniform  color  throughout  and  shows  the  completed  action  of  the  tannin 
upon  the  interior  of  the  hide. 

2.  UPPER  AND  HARNESS  LEATHERS. — These  are  made   from  lighter 
hides,  and  are  tanned  for  strength  and  flexibility  rather  than  for  weight, 
and  are  finished  with  care  to  give  perfect  pliability.    They  may  be  shaved 
or  split  leather.    The  black  color  and  finish  are  put  on  upper  leather  by 
coating  it  with  a  mixture  of  lamp-black,  linseed  oil,  and  fish  oil,  to  which 
tallow  and  wax  and  a  little  soap  have  been  added.     This  is  brushed  on, 
allowed  to  dry,  and  then  thoroughly  rubbed  in  and  the  skin  sized  with  a 
glue  size. 

3.  MOROCCO  LEATHER. — The  true  morocco  leathers  are  manufactured 
from  goat-skins.     A  cheaper  grade,  known  as  French  morocco,  is  pro- 
duced from  sheep-skins.     As  they  are  to  be  dyed  on  one  side  only,  two 


LEATHER  PRODUCTS.  371 

of  the  skins  are  fixed  face  to  face  with  the  flesh  side  inward,  so  that 
the  dye  acts  upon  one  side  of  each  skin  only.  After  dyeing  the  skins 
are  rinsed  and  drained,  saturated  with  linseed  oil  to  prevent  too  rapid 
drying,  and  then  curried  by  repeated  oiling  or  waxing  and  rubbing  with 
a  glass  "slicker." 

4.  ENAMELLED  OR  PATENT  LEATHERS. — These  are  leathers  finished 
with  a  water-proof  and  bright  varnished  surface  similar  to  lacquered 
woodwork.      The   name    "enamelled"    is    generally    applied    when    the 
leathers  are  finished  with  a  roughened  or  grained  surface,  and  ' '  patent, ' ' 
or  "japanned,"  when  the  finish  is  smooth.   Thin  and  split  hides  are  used. 
The  skins  after  drying  are  prepared  with  a  mixture  of  linseed  oil  and 
white  lead  and  heated  in  closets  to  160°  F.   (71°  C.)   or  higher,  then 
coated  with  a  varnish  of  spirits  of  turpentine,  linseed  oil,  thick  copal 
varnish,  and  asphaltum,  and  heated  again  in  closets  or  "stoves,"  as  they 
are  termed.     This  varnishing  and  heating  are  alternated,  while  the  sur- 
face is  meanwhile  rubbed  smooth  with  pumice,  until  the  desired  thickness 
is  acquired. 

5.  RUSSIA  LEATHER. — This  variety  is  peculiar  in  its  characteristic 
odor  and  ability  to  withstand  dampness  without  any  tendency  to  mould, 
both  of  which  qualities  it  owes  to  the  currying  with  the  empyreumatic 
oil  of  birch-bark.     In  Russia  the  skins  are  tanned  with  willow-bark,  but 
the  imitation  Russia  leather  made  largely  in  Germany  and  England  is 
tanned  in  the  ordinary  way  with  oak-bark.    The  birch-bark  oil  is  rubbed 
into  the  flesh  side  of  the  tanned  skins  with  cloths,  care  being  taken  not 
to  apply  so  much  as  to  cause  it  to  pass  through  and  stain  the  grain  side 
of  the  leather.     The  red  color  is  given  by  dyeing  with  Brazil-wood  or 
red  saunders,  and  the  diamond-shaped  marking  by  rolling  with  grooved 
rollers. 

6.  CHAMOIS  LEATHER  is  a  soft  felt-like  leather  originally  prepared 
from  the  skin  of  the  chamois  goat,  but  now  made  from  other  goat-skins 
and  from  the  "flesh-splits"  of  sheep-skins.     In  these  leathers  the  grain 
has  practically  been  removed  by  scraping  or  "prizing"  before  the  oil  is 
applied,  so  that  it  is  uniformly  porous  and  soft  throughout.     They 
acquire  a  yellow  color  and  a  peculiar  odor,  although  they  are  often 
bleached  whiter  by  subsequent  treatment.     (See  preceding  page.)     The 
combination  of  oil  with  the  hide  makes  chamois  leather  very  resistant 
to  water  and  allows  it  to  be  washed  without  any  change  of  nature. 

7.  WHITE-TANNED  OR  "TAWED"  LEATHER. — Skins  to  be  tanned  with 
the  hair  on,  as  sheep-skin  rugs,  etc.,  are  always  alum-tawed,  as  well  as 
light  calf  kid  and  glove  leather.     The  glove  leather  obtained  in  this 
process  has  softness  and  considerable  strength  but  is  not  thoroughly 
water-resistant,   although  the  treatment  with  egg-yolk  and  flour-paste 
which  follows  the  alum  treatment  tends  to  give  it  somewhat  of  this 
character. 

8.  CROWN  LEATHER. — This  is  a  variety  which  is  intermediate  between 
oil-tanned  and  tawed  leather,  being  stronger  than  the  first  and  more 
water-resistant  than  the  latter.    The  hides  are  first  tawed  with  the  alum 
and  salt  mixture,  then  washed  to  partially  dissolve. out  the  tawing  mate- 
rials, and  now  spread  upon  a  table  and  the  flesh  side  covered  with  a 


372  ANIMAL  TISSUES  AND  THEIR  PRODUCTS. 

mixture  of  fat,  ox-brain,  barley-flour,  and  milk.  They  are  then  put 
into  a  revolving  tumbler  and  rotated  for  a  time,  and  again  rubbed  with 
the  fat  mixture  and  rotated  if  necessary.  The  leather  readily  becomes 
mouldy,  but  seems  to  be  strong  and  specially  adapted  for  belting. 

9.  PARCHMENT  AND  VELLUM. — The  first  of  these  is  prepared  from  the 
skins  of  sheep  and  goats  and  the  second  from  the  skins  of  calves.     The 
skins  are  washed,  limed,  unhaired,  and  fleshed,  again  well  washed,  and 
then  stretched  either  upon  hoops  or  upon  a  square  wooden  frame  called 
the  herse.    On  these  the  skin  while  wet  and  soft  is  stretched  thoroughly. 
It  is  then  scraped  again  free  from  the  fleshy  matters,  the  flesh  side 
dusted  over  with  sifted  chalk  or  slaked  lime  and  rubbed  in  all  directions 
with  a  flat  piece  of  pumice-stone.    The  grain  side  is  also  scraped  with  a 
blunt  tool  and  rubbed  with  pumice.     The  skin  is  then  allowed  to  dry 
on  the  frame  in  'the  shade,  care  being  taken  to  avoid  sunshine  or  frost. 
Very  fine  vellums  are  prepared  with  the  finest  pumice-stone. 

10.  DEGRAS. — Among  the  side-products  of  the  leather  industry  is  one 
which  is  quite  valuable  for  after-use.     Degras,  originally  obtained  only 
as  a  side-product  of  the  chamois-leather  manufacture,  is  now  also  made 
specially  on  a  large  scale.     The  purest  degras  is  essentially  an  emulsion 
of  oxidized  fish  oil  produced  by  soluble  albuminoids.     That  which  is 
squeezed  out  of  the  skins  after  completion  of  the   fermentation  and 
heating,  which  makes  the  last  stage  of  the  chamois-leather  manufacture 
(see  p.  370),  is  the  finest  grade  of  degras.     That  which  is  recovered  by 
the  aid  of  caustic  alkalies  and  after-liberation  with  sulphuric  acid  is  the 
second  grade    (sod  oil).     The  great  demand  for  degras  for  currying 
purposes  has  led  to  the  manufacture  of  it  as  a  special  industry.     The 
skins  employed  for  this  purpose  are  treated  exactly  as  are  those  in  the 
normal  chamois-leather  manufacture,  but  are  used  over  and  over  until 
no  longer  capable  of  taking  up  the  oil.    An  artificial  degras  has  also  been 
made  from  oleic  acid,  fat,  and  a  little  lime  soap  to  which  some  tannic 
acid  had  been  added. 

Degras  is  of  semi-solid  consistence  and  has  a  peculiar  odor.  Its 
specific  gravity  is  higher  than  that  of  fish  oil,  and  after  dehydrating  is 
from  0.945  to  0.955.  Its  characteristic  constituent  is  the  so-called  degras- 
former,  which  in  a  genuine  degras  should  range  from  twelve  to  twenty 
per  cent.  It  is  this  which  effects  the  ready  emulsion  with  water.  The 
degras-former  is  a  brown  resinous  saponifiable  substance,  fusing  at  from 
65°  C.  to  67°  C.,  and  is  distinguished  from  fats  in  that  it  is  not  pre- 
cipitated when  in  alkaline  solution  by  salt  and  is  not  soluble  in  petro- 
leum-ether. According  to  Fahrion,  the  degras-former  is  a  mixture  of 
oxy-fatty  acids. 

IV.  Analytical  Tests  and  Methods. 

1.  QUALITATIVE  TESTS  FOR  THE  SEVERAL  TANNING  MATERIALS. — H.  R. 
Procter*  has  constructed  the  following  table  (see  p.  373)  showing  the 
reactions  of  the  several  tanning  materials. 

2.  ANALYSIS  OF  LIQUID  AND  SOLID  TANNING  EXTRACTS. — The  method 

*  Text-book  of  Tanning,  pp.  112  and  113. 


LEATHER  INDUSTRY. 


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374  ANIMAL  TISSUES  AND  THEIR  PRODUCTS. 

prescribed  by  the  "Official  and  Provisional  Methods  of  Analysis"  of  the 
U.  S.  Department  of  Agriculture  is  as  follows :  Dissolve  in  nine  hundred 
cubic  centimetres  of  water  at  80°  C.  such  a  quantity  of  the  extract  as  will 
give  from  0.35  to  0.45  gramme  of  tannin  in  one  hundred  cubic  centi- 
metres of  solution.  Allow  to  cool  slowly  for  from  twelve  to  twenty 
hours  at  a  temperature  not  below  20°  C.  and  dilute  to  one  litre. 

a.  Thoroughly  mix  the  solution,  immediately  pipette  one  hundred 
cubic  centimetres  into  a  tared  dish,  evaporate  and  dry  for  sixteen  hours 
in  a  combined  evaporator  and  dryer  at  from  98°  to  100°  C.    The  result  is 
the  total  solids. 

b.  Add  seventy-five  cubic  centimetres  of  solution  (kept  at  from  20° 
to  25°  C.  during  filtration)  to  two  grammes  of  kaolin  (free  from  soluble 
salts),  stir,  let  stand  fifteen  minutes,  decant,  and  discard  as  much  as 
possible  of  the  supernatant  liquid  and  again  add  seventy-five  cubic  cen- 
timetres of  the  tannin  solution  to  the  kaolin.     Stir  and  pour  immedi- 
ately on  a  fifteen  centimetre  folded  filter.    Keep  the  filter  full  and  the 
funnel  and  receiving  vessel  covered.     Reject  the  first  one  hundred  and 
fifty  cubic  centimetres  of  filtrate,  evaporate  and  dry  the  next  one  hun- 
dred cubic  centimetres  (which  must  be  as  clean  as  practicable)  as  before 
under  total  solids.     The  residue  is  the  soluble  solids. 

c.  Non-tannins. — Prepare   a  sufficient  quantity   of  hide   powder  in 
the  following  manner :  Digest  with  twenty-five  times  its  weight  of  water 
until  thoroughly  soaked ;  add  three  per  cent,  of  chrome  alum  in  solution, 
agitate  occasionally  for  several  hours  and  allow  to  stand  over  night. 
"Wash  by  squeezing  through  linen,  until  the  wash  water  gives  no  pre- 
cipitate  with  barium    chloride.      Squeeze   the   hide,    using    a    press   if 
necessary,  so  that  it  contains  from  seventy  to  seventy-five  per  cent,  of 
water    and    determine    moisture     (twenty    grammes    is    a    convenient 
quantity). 

Add  to  two  hundred  cubic  centimetres  of  the  tannic  solution  such  a 
quantity  of  the  cut  hide  as  contains  from  twelve  to  thirteen  grammes 
of  dry  hide,  shake  for  ten  minutes  in  a  shaker  and  squeeze  immediately 
through  linen,  add  two  grammes  of  kaolin  to  the  filtrate,  stir  and 
filter  through  a  folded  filter,  returning  until  clear.  Evaporate  and  dry 
one  hundred  cubic  centimetres  as  in  previous  section.  Correct  the 
weight  of  the  residue  for  dilution  caused  by  the  water  contained  in 
the  cut  hide  powder.  This  non-tannin  filtrate  must  not  give  a  precipi- 
tate with  a  gelatine  salt  solution  (one  per  cent,  of  gelatine  and  ten 
per  cent,  of  salt). 

d.  The  difference  between  the  weight  of  the  soluble  solids  and  the 
corrected  non-tannin  residue  is  the  weight  of  tannin  in  one  hundred 
cubic  centimetres  of  solution.  s 

3.  QUANTITATIVE  ESTIMATION  OF  TANNIN. — Of  the  numerous  pro- 
cesses that  have  been  described  for  this  purpose,  the  only  one  generally 
accepted  as  capable  of  sufficient  accuracy  is  Lowenthal's  permanganate 
method.  This  depends  upon  the  oxidation  of  the  tannin,  etc.,  by  per- 
manganate of  potash  in  acid  solution  in  the  presence  of  indigo,  which 
serves  as  indicator,  as  its  oxidation  shows  the  end  of  the  reaction.  As 
solutions  of  commercial  tanning  materials  contain  other  oxidizable 


LEATHER  INDUSTRY.  375 

matters  besides  tannins,  it  is  necessary  to  separate  these  and  titrate  a 
second  time  in  order  to  ascertain  the  volume  of  permanganate  actually 
required  by  the  tannin  present.  This  separation  may  be  effected  by 
digestion  with  hide-raspings,  or  more  conveniently  by  a  solution  of  gela- 
tine. In  practice,  a  mixed  solution  of  gelatine  and  common  salt  is  used 
to  which  a  small  quantity  of  sulphuric  or  hydrochloric  acid  is  added. 
Procter  has  also  improved  the  process  by  adding  kaolin,  after  the  gela- 
tine and  salt  have  removed  the  tannin,  for  the  purpose  of  facilitating 
filtration. 

The  special  precautions  and  details  of  the  process  as  generally  prac- 
tised and  as  modified  by  the  Commission  of  German  Technical  Chemists 
are  given  in  Allen.*  The  results  are  always  stated  in  terms  of  crystal- 
lized oxalic  acid  to  which  the  tannin  is  equivalent  in  reducing  power 
upon  the  permanganate  solution,  and  are  gotten  by  the  aid  of  the  pro- 
portion c:  (a — &)  :  :  63 :  z,  in  which  c  represents  the  volume  of  per- 
manganate needed  for  ten  cubic  centimetres  of  decinormal  oxalic  acid, 
a  and  b  the  volume  of  permanganate  needed  for  the  tanning  infusion 
before  and  after  precipitation  of  the  tannin.  The  shaking  method  with 
chromed  hide-powder,  as  given  on  the  preceding  page,  is  that  gen- 
erally used  by  American  leather  chemists.  It  is  objected  to,  however, 
by  European  chemists,  that  the  shaking  introduces  abnormal  conditions 
so  that  some  of  the  non-tannins  are  absorbed  and  that  the  result  will 
vary  somewhat  with  the  degree  of  chroming  of  the  hide-powder. 
Many  workers,  therefore,  prefer  the  bell,  as  proposed  by  Procter,  which 
is  packed  with  the  chromed  hide-powder  and  the  shaking  is  dispensed 
with.  The  most  recent  method  adopted  by  the  International  Association 
of  Leather  Trade  Chemists  and  officially  promulgated  by  them  is  found  in 
Trotman's  Leather  Trades  Chemistry,  p.  146.  f 

4.  DETERMINATION  OF  ACIDITY  OF  TAN-LIQUORS. — A  method  for  the 
determination  of  volatile  and  non-volatile  organic  acids  and  the  sul- 
phuric acid  present  in  acid  tan-liquors  has  been  given  by  Kohnstein 
and  Simand.J  One  hundred  cubic  centimetres  of  the  tanning  liquor  are 
taken  and  eighty  cubic  centimetres  distilled  off,  the  residue  diluted  and 
again  distilled  with  steam.  The  acidity  of  the  distillate  is  determined, 
and  the  result  is  the  volatile  organic  acids  reckoned  in  terms  of  acetic 
acid.  To  determine  the  non-volatile  organic  acids,  eighty  cubic  centi- 
metres of  the  tanning  infusion  is  treated  with  three  to  four  grammes 
of  freshly-ignited  magnesium  oxide  and  the  mixture  left  for  some  hours 
with  frequent  agitation,  when  the  filtered  liquid  will  be  nearly  colorless 
and  perfectly  free  from  tannin.  The  magnesia  in  solution  is  determined 
in  an  aliquot  part  of  the  filtered  solution,  and  will  be  equivalent  to  the 
total  free  acids  of  the  liquor  exclusive  of  the  tannic  acid.  Another 
portion  of  the  filtrate  is  evaporated  to  dryness,  the  residue  gently  ignited, 
moistened  with  carbonic  acid  water,  and  dried.  It  is  then  boiled  with 
distilled  water  and  the  solution  filtered.  The  carbonate  of  magnesia 

*  Allen,  Commercial  Organic  Analysis,  2d  ed.,  vol.  iii,  Part  i,  pp.  109-116. 

t  Leather  Trades  Chemistry,  S.  R.  Trotman.  1908,  J.  B.  Lippincott  Co.,  Phila. 

J  Dingier,  Polytech.  Journ.,  256,  pp.  38  and  64. 


376  ANIMAL  TISSUES  AND  THEIR  PRODUCTS. 

remaining  insoluble  represents  the  total  organic  acids,  and  can  be  more 
accurately  determined  by  converting  the  magnesia  into  pyrophosphate 
and  weighing.  If  these  total  organic  acids  be  calculated  in  terms  of 
acetic  acid,  and  the  previously  found  volatile  acids,  reckoned  as  acetic,  be 
deducted,  the  difference  represents  the  non-volatile  organic  acids.  The 
magnesia  remaining  in  the  filtrate  from  the  carbonate  of  magnesia  is 
combined  as  sulphate,  and  when  determined  gives  the  sulphuric  acid  of 
the  original  liquors. 

5.  ANALYSIS  OF  LEATHER. — It  is  possible  in  the  case  of  a  leather  to 
determine  the  percentage  of  moisture,  total  fats,  water-soluble  matter, 
insoluble  fibre,  and  ash.  In  the  case  of  mineral  tannages,  the  quantita- 
tive determination  of  the  chief  constituents  of  the  ash  is  of  special 
importance.  The  fats  are  determined  by  extraction  in  a  Soxhlet  appa- 
ratus, as  described  in  a  previous  chapter,  carbon  disulphide  or  petro- 
leum-ether being  used  as  solvent.  The  dry  leather  residue  remaining 
after  this  extraction  is  digested  for  some  hours  with  distilled  water  at 
40°  C.  and  then  thoroughly  extracted  by  fresh  water  at  the  same  tem- 
perature. The  washings  are  then  brought  to  fixed  volume  and  the  resi- 
due determined  in  an  aliquot  portion.  Uncombined  tannin  may  also  be 
determined  in  this  aqueous  extract  by  means  of  the  hide-powder  or  Low- 
enthal  method.  The  total  ash  is  obtained  by  igniting  a  separate  quantity 
of  the  leather.  This  is  chipped  in  small  fragments  and  ignited  grad- 
ually in  small  portions  in  a  platinum  dish.  After  the  leather  swells  and 
carbonizes,  it  can  be  burned  completely  at  a  dull-red  heat  without  loss 
of  the  mineral  salts. 

B.  GLUE  AND  GELATINE  MANUFACTURE. 

Glue  is  a  decomposition  product  of  many  nitrogenous  animal  tissues. 
These  lose  on  heating  with  water  (analogous  to  starch-granules)  their 
organized  structure,  swell  up,  and  gradually  go  into  solution.  The  solu- 
tions, even  when  very  dilute,  gelatinize  on  cooling,  forming  a  jelly, 
which  dries  to  a  horny  translucent  mass.  This  mass  is  glue  or  gelatine, 
as  the  finer  grades  are  termed.  It  dissolves  in  hot  water  to  a  liquid 
possessing  notable  cementing  power.  Neither  the  original  solution 
obtained  from  the  nitrogenous  tissues  nor  the  jelly  formed  from  it  on 
cooling  have  any  cementing  power.  This  is  only  acquired  when  the  jelly 
has  dried  to  the  hard  mass  known  as  the  glue.  Two  proximate  principles 
seem  to  be  present  as  characteristic  in  all  preparations  of  glue:  glutin, 
obtained  chiefly  from  the  hide  and  larger  bones,  and  chondrin,  from  the 
young  bones  while  yet  in  the  soft  state  and  the  cartilage  of  the  ribs, 
and  joints.  Of  these,  the  former  much  exceeds  the  latter  in  adhesive 
power,  and  is  therefore  sought  to  be  obtained  predominantly  in  the 
glue  manufacture. 

I.  Raw  Materials. 

1.  HIDES  AND  LEATHER. — The  corium  of  the  animal  hides  (see  p.  356) 
is  the  most  important  glue-yielding  material  to  be  had.  Neither  the 
epidermis  nor  the  underlying  fat-tissue  contribute  to  the  glue  produc- 
tion, but  have  rather  an  injurious  effect  when  present.  "What  is  known 


GLUE  AND  GELATINE  MANUFACTURE.  377 

as  ''glue-stock"  is  made  up  of  the  trimmings  from  the  ox.  sheep,  and 
calf-skins,  the  refuse  of  the  beam-house,  and  scraps  of  parchment,  which 
have  been  softened  and  unhaired  by  liming  and  are  in  condition  for 
immediate  boiling.  Of  still  greater  value  are  the  so-called  calves'  heads, 
which  after  liming  and  drying  form  a  special  article  of  commerce.  The 
amount  of  glue  obtainable  from  these  various  materials  varies  from 
fifteen  to  sixty  per  cent.  According  to  Fleck,*  the  scraps  from  the 
alum-tawing  process  yield  forty-five  per  cent.,  those  from  the  ox-hides 
thirty  per  cent.,  hare-  and  rabbit-skins  and  parchment  trimmings  fifty 
to  sixty  per  cent.,  foot  and  tail  pieces  of  oxen  fifteen  to  eighteen  per 
cent.,  other  scraps  from  the  tanneries,  such  as  ear-laps  of  sheep  and 
cows,  sheep's  feet,  etc.,  thirty-eight  to  forty-two  per  cent.  Scraps  of 
bark-tanned  leather,  such  as  shoemaker's  and  saddler's  trimmings,  are 
also  available  after  a  special  treatment  for  the  removal  of  the  tannin. 
(See  p.  379.) 

2.  BONES. — The  bones  contain  on  an  average  nearly  one-third  (32.2 
per  cent.)  of  their  weight  of  organic  constituents,  extracted  by  boiling 
and  converted  into  glue,  which,  however,  is  inferior  in  adhesive  power 
to  that  prepared  from  animal  skins.    The  soft  bones  of  the  head,  shoul- 
ders, ribs,  legs,  and  breast,  and  especially  deer's  horns  and  the  bony  core 
of  the  horns  of  horned  cattle,  yield  a  larger  quantity  of  glue  than  the 
hard  thigh-bones  and  the  thick  parts  of  the  vertebra,  which  are  prin- 
cipally composed  of  calcium  phosphate  and  require  a  more  prolonged 
treatment  to  extract  the  glue-making  constituents. 

3.  FISH-BLADDER. — The  inner  skin  of  the  air-bladders  of  the  several 
varieties  of  sturgeon  and  cod  furnishes  a  very  pure  glue  substance,  which 
on  account  of  its  purity  is  preferably  used  for  culinary  and  medicinal 
purposes,  and  is  known  as  "isinglass."    It  is  inferior  in  adhesive  power 
to  hide-glue,  but  on  account  of  its  freedom  from  color,  taste,  and  odor, 
and  its  almost  perfect  solubility  in  hot  water,  commands  a  higher  price. 
It  is  used  for  food  preparations,  for  clarifying  wine,  beer,  and  other 
liquids.    The  chief  production  of  isinglass  is  from  the  sturgeon  in  Rus- 
sia, on  the  borders  of  the  Caspian  and  the  Black  Sea. 

4.  VEGETABLE  GLUE. — Certain  species  of  algae   (Plocaria  tenax  and 
others)  found  in  Chinese  and  Japanese  waters  when  cleansed  and  boiled 
yield  a  product  known  under  the  several  names  of  "Chinese  isinglass" 
and  ' '  agar-agar. ' '    Of  similar  character  is  no  doubt  the  ' '  algin ' '  obtained 
from  Scotch  alga3  by  E.  C.  C.  Stanford. f 

n.  Processes  of  Manufacture. 

1.  MANUFACTURE  OF  GLUE  FROM  HIDES. — The  hide  trimmings  and 
offal,  if  in  the  fresh  state,  must  first  of  all  be  well  limed, — that,  is,  treated 
with  milk  of  lime  in  pits  for  a  period  varying  from  ten  to  forty  days, 
according  to  the  character  and  source  of  the  hides,  the  lime  being  fre- 
quently renewed.  The  lime  softens  and  swells  the  hide-tissue,  saponifies 

*  Die  Fabrikation  Chemischer  Producte,  etc.,  p.  GO. 
t  Soc.  Chem.  Ind.  Jour.,  1884,  p.  297. 


378 


ANIMAL  TISSUES  AND  THEIR  PRODUCTS. 


FIG.  97. 


the  fats,  and  dissolves  in  large  part  the  coriin,  blood,  and  flesh-particles 
which  do  not  form  glue.  The  glue-stock  is  then  thoroughly  washed  free 
from  the  lime,  lime  salts,  and  dirt,  usually  by  putting  it  in  nets  or 
wicker  baskets  which  are  suspended  in  running  water.  The  liming  also 
serves  to  preserve  the  glue-stock  in  case  it  is  not  to  be  immediately  worked 
up.  After  washing  it  is  spread  out  to  dry.  The  lime  scum  from  the 
pits  is  often  utilized  in  fertilizer  manufacture.  Caustic  soda  has  also 

been  used  instead  of  milk  of 
lime  for  this  treatment.  A  short 
treatment  with  chloride  of  lime 
immediately  after  taking  the 
stock  out  of  the  lime-pits  has 
also  been  found  to  give  the  glue 
a  bright  color  and  excellent  ad- 
hesive power.  In  recent  years 
sulphurous  acid  has  been  used 
with  advantage  to  cleanse  and 
prepare  the  glue-stock,  as  it 
bleaches  and  at  the  same  time 
swells  the  hide,  at  least  as  well 
as  can  be  done  by  the  lime. 

The  boiling  and  conversion 
of  the  glue-stock  into  solution 
may  be  effected  by  heating  with 
water  or  with  steam.  The  use 
of  steam,  either  from  closed 
pipes  or  direct  steam  from  per- 
forated pipes,  greatly  improves 
the  extraction,  shortening  the 
time  required  and  improving 
the  quality  of  the  product. 
Direct  high-pressure  steam 
blown  into  closed  vessels  has 
been  found  to  be  quite  effective 
in  rapidly  melting  down  the 
glue-stock  and  producing  a  con- 
centrated solution. 

The  use  of  vacuum-pans  and  the  extraction  by  steam  under  reduced 
pressure  and  at  lower  temperatures  has  also  been  found  very  satisfactory 
in  giving  a  good  product  in  which  the  adhesive  qualities  of  the  gluten 
are  in  no  way  impaired.  A  form  of  vacuum  pan  designed  for  the  evap- 
oration of  thin  glue  extraction  liquors  is  shown  in  Fig.  97.  The 
solution  must  be  freed  from  any  melted  fat  and  lime  soaps  by  skimming 
and  from  suspended  impurities  by  settling,  by  filtering  through  linen 
bags,  or  clarifying  by  the  use  of  bone-black.  The  addition  of  alum  as 
sometimes  practised  has  an  injurious  effect  upon  the  adhesive  power  of 
the  product.  The  residue  of  the  glue-stock  left  unextracted  is  pressed 
out,  dried,  and  sold  as  a  fertilizer  containing  about  four  per  cent,  of 


GLUE  AND  GELATINE  MANUFACTURE.  379 

nitrogen.  The  clarified  glue  solution  is  poured  into  shallow  wooden 
moulds  some  six  inches  in  depth,  in  which  as  it  cools  it  gelatinizes  to  a 
brownish-yellow  jelly  containing  from  eighty  to  ninety  per  cent,  of 
water.  The  block  of  jelly  is  then  turned  out  upon  a  smooth  table,  pre- 
viously moistened  to  prevent  adherence,  and  sawed  by  horizontal  wires 
into  thin  slabs,  which  are  again  cut  by  vertical  wires  into  strips  of  the 
proper  width. 

The  drying  of  the  jelly  is  one  of  the  most  troublesome  parts  of  the 
whole  process,  as  it  must  take  place  rapidly  so  that  the  glue-making 
material  may  not  spoil,  as  it  is  very  prone  to  do  while  in  the  jelly  form, 
and,  on  the  other  hand,  the  heat  should  not  exceed  20°  C.  (68°  F.).  It 
may  take  place  with  this  limitation  of  temperature  in  the  open  air,  if 
the  air  is  not  too  moist  or  too  dry,  both  of  which  conditions  are  unfavor- 
able. It  is  now  generally  effected  in  drying-rooms  in  which  a  current 
of  warm  dry  air  at  the  right  temperature  is  made  to  circulate.  As  the 
surface  of  the  cakes  after  drying  is  generally  rough  and  dull,  it  is 
improved  in  appearance  by  moistening  with  warm  water,  brushing  with 
a  soft  brush,  and  again  drying. 

2.  MANUFACTURE  OF  GLUE  FROM  LEATHER-WASTE. — Before  attempt- 
ing to  boil  the  leather-waste  to  glue,  the  removal  of  all  traces  of  tannic 
acid  becomes  absolutely  necessary,  since  the  retention  of  the  smallest 
quantity  prevents  the  animal  tissue  from  dissolving  in  water.    The  waste 
must  therefore  be  comminuted  as  thoroughly  as  possible  to  facilitate  the 
complete  removal  of  the  tannic  acid.     This  is  done  frequently  in  the 
"hollander"  used  for  paper-pulp,  and  the  washed  and  ground  leather- 
waste  then  heated  in  a  pressure-boiler  under  a  pressure  of  two  atmos- 
pheres with  fifteen  per  cent,  of  its  weight  of  slaked  lime.     After  thor- 
ough washing,  the  residue  is  ready  for  use  as  glue-stock. 

3.  MANUFACTURE  OF  GLUE  OR  GELATINE  FROM  BONES. — Two  methods 
have  been  followed  for  the  extraction  of  gelatine,  as  the  product  is 
generally  called  in  this  case,  from  bones.     The  bones  are  either  boiled 
under  pressure,  or  they  are  treated  with  hydrochloric  acid  to  remove 
the  calcium  phosphate  and  afterwards  boiled  for  the  extraction  of  the 
gelatine.    The  bones  in  either  case  are  with  advantage  deprived  of  their 
fat  first,  which  is  done  either  by  heating  them  with  water  and  steam 
in  boiler-shaped  vessels,  when  the  fat  rises  and  can  be  skimmed  off  from 
the  water,   or  in  closed  vessels  with  volatile   solvents  like  petroleum- 
benzine  and  carbon  disulphide.     The  older  process  of  extracting  the 
gelatine   by   boiling   the    powdered   bones   with  water   under   pressure 
decomposes  a  portion  of  the  valuable  material,  and  is  now  generally 
replaced  by  the  method  of  treatment  with  hydrochloric  acid  for  the 
removal  of  the  calcium  phosphate.     The  crushed  bones  are  placed  in 
wooden  vats  with  dilute  hydrochloric  acid  of  specific  gravity  1.05  (forty 
litres  of  acid  to  ten  kilos,  of  bones)  and  allowed  to  remain  for  several 
days.    They  are  then  placed  in  lime-water  for  a  time,  well  washed,  and 
boiled  eight  to  ten  hours  with  a  large  excess  of  water,  or  converted  more 
rapidly  into  gelatine  solution  by  the  aid  of  steam.     The  resulting  solu- 
tion is  filtered  through  cloth,  bleached  by  sulphurous  oxide,  and  poured 


380  ANIMAL  TISSUES  AND  THEIR  PRODUCTS. 

into  forms  to  gelatinize.  The  manufacture  of  bone  gelatine  is  fre- 
quently combined  with  the  fertilizer  manufacture,  as  the  calcium  phos- 
phate extracted  by  the  hydrochloric  acid  treatment  contains  from 
eighteen  to  twenty  per  cent,  of  phosphoric  acid.  The  newer  method 
of  extracting  the  fat  by  volatile  solvents  yields  five  to  six  per  cent,  of 
fat  without  injury  to  the  gelatine  of  the  bones,  while  the  older  method 
of  boiling  out  the  fat  yields  from  three  to  four  per  cent,  only  and  tends 
to  lessen  the  yield  of  gelatine. 

4.  MANUFACTURE  OF  FISH  GELATINE. — The  swimming-bladders  of  the 
fish  are  taken  and  thoroughly  washed  in  water  from  all  fatty  and 
bloody  particles.  They  are  then  removed  and  cut  longitudinally  into 
sheets,  which  are  exposed  to  the  sun  and  air  to  dry,  with  the  outer  face 
turned  down  upon  boards  of  linden  or  bass-wood.  The  inner  face 
of  the  bladders  is  pure  isinglass,  which  when  partially  dried  can  with 
care  be  removed  from  the  outer  muscular  layer.  The  isinglass  layer, 
possessing  a  silvery  white  lustre,  is  taken  either  in  sheets,  rings,  or 
horseshoe-shaped  strips,  etc.,  bleached  with  sulphurous  acid,  and  then 
thoroughly  dried. 

A  product  distinct  from  isinglass  and  known  as  fish  glue  is  prepared 
by  boiling  the  sldn  and  muscular  tissue  of  fish,  and  more  resembles 
ordinary  hide  glue  in  its  adhesive  properties,  but  is  offensive  in  odor. 
It  is  prepared  from  the  scales  and  skins  of  large  fish  like  the  carp  by 
acting  on  them  with  hydrochloric  acid  as  upon  bones  and  then  extract- 
ing with  water. 

m.  Products. 

1.  HIDE  GLUE  is  the  variety  which  shows  most  strongly  the  adhesive 
property,  and  hence  is  that  manufactured  for  joiner's  and  carpenter's 
use.    Its  color  may  vary  considerably  without  any  impairing  of  its  adhe- 
sive power.     It  is  rarely  perfectly  colorless  or  transparent.     A  gray  to 
amber  or  brown-yellow  color  and  translucent  or  partially  opaque  ap- 
pearance is  more  usual.     It  should  be  clear,  dry,  and  hard,  and  possess 
a  glassy  fracture.     It  should  swell  up  but  not  dissolve  in  cold  water, 
but  dissolve  in  water  at  62.5°   C.    (144.5°   F.).     Inorganic  substances 
(such  as  white  lead)   are  intentionally  introduced  into  some  varieties, 
such  as  the  Russian  glue,  without  injury  to  their  adhesive  power. 

The  variety  known  as  "Cologne  glue"  is  manufactured  from  scrap 
hide,  which  after  liming  is  carefully  bleached  in  a  chloride  of  lime 
bath  and  then  thoroughly  washed. 

"Russian  glue,"  as  stated,  contains  some  inorganic  admixture.  It  is 
of  a  dirty-white  color,  and  contains  from  four  to  eight  per  cent,  of  white 
lead,  chalk,  zinc-white,  or  barytes. 

"Size  glue"  and  "Parchment  glue"  are  both  skin  glues  prepared 
with  special  care. 

2.  BONE  GLUE  (OR  BONE  GELATINE). — Bones  yield  a  product  of  less 
adhesive  power  than  the  glue  of  skins  and  tendons,  but  when  carefully 
worked  the  product  is  clearer  and  is  free  from  offensive  odor.     It  is 


GLUE  AND  GELATINE  MANUFACTURE.  381 

therefore  much  used  for  culinary  purposes  and  for  medicinal  applica- 
tions, and  for  fining  or  clarifying  beer,  wine,  and  other  liquids  it  has 
largely  superseded  isinglass.  The  gelatine  thus  used  must,  however,  be 
absolutely  tasteless  and  free  from  odor. 

Bone  gelatine  is  now  made  use  of  very  largely  in  the  manufacture 
of  gelatine  capsules,  etc.,  for  medicinal  uses,  of  court-plaster  for  apply- 
ing to  wounds,  and  of  gelatine  emulsions  with  bromide  and  chloride  of 
silver  for  coating  the  photographic  dry  plates.  Mixed  with  glycerine 
it  makes  an  elastic  mass  used  for  printers'  rollers,  for  hectographs,  etc. 

"Patent  Glue"  is  a  very  pure  variety  of  bone  glue  of  deep  dark- 
brown  color.  It  is  very  glossy  and  swells  up  very  much  in  water. 

3.  ISINGLASS   (OR  FISH  GELATINE). — This  is  the  finest  and  best  of 
animal  glues.     The  best  isinglass  should  be  pure  white,  nearly  trans- 
parent, dry  and  horny  in  texture,  and  free  from  smell.     It  dissolves 
in  water  at  from  35°  to  50°  C.  (95°  to  122°  F.)  without  any  residue, 
and  in   cooling  should   produce   an  almost  colorless   jelly.      The   com- 
mercial varieties  of  isinglass  are  the  Russian   (the  best  coming  from 
Astrachan),  North  American   (or  New  York},  East  Indian,  Hudson's 
Bay,  Brazilian,  and  German  (or  Hamburg). 

4.  LIQUID  GLUE. — By  the  action  of  nitric  or  acetic  acid  upon  a  solu- 
tion of  glue  its  power  to  gelatinize  may  be  completely  arrested  while 
its  adhesive  power  is  not  at  all  interfered  with.     Thus,  if  one  kilo,  of 
glue  is  dissolved  in  one  litre  of  water  and  .2  kilo,  of  nitric  acid  of  36°  B. 
be  added,  after  the  escape  of  the  nitrous  fumes  we  have  a  solution  that 
will  not  gelatinize  on  cooling,  although  it  has  the  full  adhesive  power 
of  the  glue.     Four  parts  of  transparent  gelatine,  four  parts  of  strong 
vinegar,  one  part  of  alcohol,  and  a  small  amount  of  alum  will  also 
yield  an  excellent  liquid  glue. 

IV.  Analytical  Tests  and  Methods. 

The  nature  of  glue  makes  it  rather  a  question  of  physical  and 
mechanical  tests  as  to  quality  of  a  given  sample  than  of  chemical  tests. 

1.  ABSORPTION  OF  WATER. — Thus  the  relative  amount  of  water  that 
a  given  sample  will  take  up  when  laid  in  cold  water  is  regarded  as  a 
moderately  fair  criterion  of  its  quality.  A  weighed  sample  is  laid  for 
twenty-four  hours  in  cold  water  (not  exceeding  12°  C.  (53.4°  F.)  in 
temperature),  and  at  the  expiration  of  that  time  the  excess  of  water 
having  been  poured  off,  the  jelly  is  weighed.  Very  good  varieties  (white 
gelatine  prepared  from  bones)  will  take  up  thirteen  times  the  quantity 
of  water  in  gelatinizing,  second  quality  glue  ten  times,  and  inferior 
grades  only  about  six  times  the  amount  of  water.  At  the  same  time  the 
consistency  of  the  jelly  formed  must  also  be  taken  into  consideration. 
A  firm  jelly  produced  by  the  absorption  of  a  large  quantity  of  water 
indicates  a  glue  of  the  best  quality. 

Two  observations  are  of  value  in  this  connection:  first,  glue  twice 
dissolved  and  again  dried  is  capable  of  drying  out  more  thoroughly  and 
of  showing  water-assimilating  properties  on  redissolving  more  fully 


382  ANIMAL  TISSUES  AND  THEIR  PRODUCTS. 

than  glue  obtained  by  a  single  drying;  and,  second,  that  hide  glue  on 
taking  up  smaller  quantities  of  water  becomes  very  soft  and  more  dif- 
ficult to  weigh  accurately  than  bone  glue,  which,  with  larger  amounts 
of  absorbed  water,  still  forms  a  firm  jelly.  This  difference  in  behavior 
alone  is  capable  of  giving  an  indication  of  the  source  of  the  glue. 

2.  INORGANIC  IMPURITIES. — The  presence  of  inorganic  salts,  as  in  the 
case  of  Russian  glue,  can  be  determined  by  the  use  of  the  appropriate 
reagents,  and  the  amount  also  quantitatively  determined. 

3.  ADULTERATION  OP  ISINGLASS  WITH    GLUE. — Isinglass  is  sometimes 
adulterated  by  rolling  up  sheets  of  gelatine  (bone  gelatine)  between  the 
layers  of  true  isinglass  and  drying  them  in  this  condition. 

Redwood  and  Letheby  have  observed  that  the  ash  of  pure  isinglass 
does  not  exceed  .9  per  cent.,  while  glue  contains  from  two  to  four  per 
cent,  of  ash.  An  adulterated  sample  of  isinglass  gave  Letheby  1.5  per 
cent,  of  ash. 

On  heating  with  water,  true  isinglass  gives  only  a  peculiar  fish  or 
algae  odor,  while  the  adulterated  isinglass  gave  a  strong  glue-like  odor 
at  once  recognizable. 

V.  Bibliography  and  Statistics. 

» 

BIBLIOGRAPHY. 

ON   LEATHER. 

1873. — Die  Rohstoffe  des  Pflanzenreiches,  J.  Wiesner,  Leipzig. 
1876. — Leather  Manufacture,  J.  S.  Schultz,  New  York. 
1877. — Die  Weissgerberei    etc.,  F.  Wiener,  Leipzig. 

Leder-Industrie-Bericht    iiber    die    Austellung    in    Philadelphia,    W.    Eitner, 

Vienna. 
1880. — Classification  de  300  Matidres  tannantes,  R.  J.  Bernardin,  Gand. 

Die  Gerberinden,  F.  R.  von  Hohnel,  Berlin. 

The  Culture  of  Sumach,  Department  of  Agriculture,  Special  Report  26,  W. 

McMurtrie,  Washington. 

1881. — Matieres  premieres  organiques,  Geo.  PennetieT,  Paris. 
1882. — Die  Grundziige  der  Lederbereitung,  Chr.  Heinzerling,  Braunschweig. 
1885. — Bericht  der  Commission  der  Gerbstoffbestimmung,  etc.,  C.  Councler,  Cassel. 

Text-book  of  Tanning,  H.  R.  Procter,  London  and  New  York. 
1886. — Cuirs  et  Peaux,  Tannage,  etc.,  H.  Villain,  2me,  Paris. 
1888. — Abriss  der  chemischen  Technologic,  Chr.  Heinzerling,  Berlin. 
1889. — Handbuch     der    technisch-chemischen     Untersuchungen,     6te    Auf.,     Bolley, 
Leipzig. 

Hand-book  of  Commercial  Geography,  Geo.  Chisholm,  London  and  New  York. 

Traite  pratique  de  la  Fabrication  des  Cuirs,  etc.,  A.  M.  Villon,  Paris. 
1890. — Lehrbuch  der  technischen  Chemie,  H.  Ost,  Berlin. 

Die  Lohgerberei,  F.  Wiener,  2te  Auf.,  Leipzig, 
1891. — Leather  Manufacture,  J.  W.  Stevens,  London. 

Praktisches  Lehrbuch  der  Lohgerberei,  S,  Kas,  Weimar. 
1892. — Industrie  des  Cuirs  et  des  Peaux,  T.  Jean,  Paris. 

The  Tannins,  vol.  i.,  Henry  Trimble,  Philadelphia. 
1893. — Die  Herstellung  der  Lohgaren  Leder,  L.  Hoffmann,  Weimar. 
1894. — Cuirs  et  Peaux,  Voinesson  de  Lavelines,  Paris. 

The  Tannins,  vol.  ii.,  Heniy  Trimble,  Philadelphia. 

1896. — Anleitung  zur  Mikrochemischen  Analyse,  2te  Heft    (Die  wichtigsten  Faser- 
stoffe),  H.  Behrens,  Leipzig. 


BIBLIOGRAPHY  AND  STATISTICS. 


383 


1897. — The  Art  of  Leather  Manufacture,  Alexander  Watt,  4th  ed.,  London. 

The  Manufacture  of  Leather,  C.  T.  Davis,  2d  ed.,  Philadelphia. 
1898. — Leather  Industries  Laboratory  Book,  H.  R.  Procter,  London. 
1900. — Leather- Worker's  Manual,  H.  C.  Standage,  London. 
1901. — Die  Feinleder  fabrikation,  etc.,  Joseph  Borgman,  Berlin. 
1903. — The  Principles  of  Leather  Manufacture,  H.  R.  Procter,  New  York. 

Die  Chromgerburg,  S.  Hegel,  J.  Springer,  Berlin. 

1906. — Leather  Manufacturer,  A  Practical  Hand-book,  A.  Watt,  London. 
1908. — Leather  Industries  Laboratory  Book,  H.  R.  Procter,  2d  ed.,  New  York. 

Leather  Trades  Chemistry,  S.  R.  Trotman,  London. 

Practical  Tanning,  L.  A.  Fleming,  H.  Carey  Baird  &  Co.,  Philadelphia. 
1909. — Tanners'  and  Chemists'  Hand-book,  L.  E.  Levi  and  E.  V.  Manuel,  Milwaukee. 

Leder  fabrikation,  H.  Kronlein,  M.  Janecke,  Hanover. 

Die  Pflanzlichen  Gerbstoffe,  H.  Franke,  Magdeburg. 
1910. — Praxis  und  Theorie  der  Leder-Erzeugung,  J.  Jettmar,  J.  Springer,  Berlin. 

ON   GLUE  AND  GELATINE. 

1878. — Die   Fabrikation   chemischer   Producte  aus   thierischen   Abfallen,   H.   Fleck, 

Braunschweig. 
1884. — Die  Verwerthung  der  Knochen  auf  chem.  Wege,  W.  Friedberg,  Vienna. 

Glue  and  Gelatine,  Davidowsky,  translated  by  H.  Brannt,  Philadelphia. 
1893. — Cements,  Pastes,  Glues,  and  Gums,  H.  C.  Standage,  London. 
1900. — Glue  and  Glue-testing,  S.  Rideal,  London. 
1901. — Glues  and  Gelatines,  R.  L.  Fernbach,  Van  Nostrand  Co.,  New  York. 

Bone  Products  and  Manures,  Thomas,  Lambert,  London. 
1907. — Die  Fabrikation  von  Leim  und  Gelatine,  Dr.  L.  Thiele,  Hannover. 
1911.— Die  Kitte  und  Klebstoffe,  W.  Jeep,  5te  Auf.,  Leipzig. 


STATISTICS. 

1.  IMPORTATIONS  OF  TANNING  MATERIALS  INTO  THE  UNITED  STATES. — 

1908.  1909.  1910. 

Gambler  or  terra  Japonica    (pounds)    26,681,791  30,992,245  25,572,655 

Valued  at  $894,752  $1,313,997  $1,255,296 

Quebracho  extract  (pounds)  98,186,787  102,004,981  95,183,073 

Valued  at  $2,260,304  $2,740,530  $3,021,902 

Quebracho-wood  (tons)  48,871  66,113  80,210 

Valued  at  $612,971  $731,795  $1,058,647 

Sumac  (pounds)  8,576,091  10,974,613  13,632,861 

Valued  at    $227,611  $293,299  $299,170 

2.  IMPORTATION  OF  SKINS  AND  HIDES  INTO  THE  UNITED  STATES. — 

1908.  1909.  1910. 

Goat-skins   (pounds)    63,640,758  104,048,244  115,844,758 

Valued  at    $17,325,126  $26,023,914  $30,837,590 

Sheep-skins   (pounds)    48,906,326  67,406,131 

Valued  at    $8,276,637  $11,289,158 

Calf-skins    (pounds)    75,503,451 

Valued  at    $17,922,051 

Cattle-hides    (pounds)     98,353,249  192,252,083  285,468,821 

Valued   at    $12,044,435  $23,795,602  $42,306,943 

Horse-skins   (pounds)    19,512,397 

Valued  at    $3,080,484 

All  others   (pounds)    120,770,918  99,347,672  12,258,753 

Valued  at    $25,400,575  $20,319,171  $2,418,414 

Total  (pounds)    282,764,925  444,554,325  608,619,028 

Valued   at    $54,770,136  $78,487,324  $112,247,836 


384 


ANIMAL  TISSUES  AND  THEIR  PRODUCTS. 


3.  LEATHER  INDUSTRY  ACCORDING  TO  CENSUS  OF  1905. — 

Raw  materials  used — 

Number.  Value. 

Hides  and  skins  of  all  kinds 17,581,613  $89,126,593 

Tanning  materials — 

Hemlock   bark    (cords)     1,000,328  8,471,292 

Oak  bark    (cords)    422,269  3,765,559 

Gambier    (bales)     80,610  752,347 

Hemlock   extract    (barrels)     21,766  265,665 

Oak-bark  extract  (barrels) 214,391  2,300,395 

Quebracho 2,490,487 

Sumac    (tons) 7,958  "338,614 

Chemicals 2,847,441 

All  other  materials  used  in  tanning 3,798,244 

Oil,  degras,  tallow,  etc.,  used  in  currying 3,807,186 

Aggregate  value  of  products    252,620,986 

4.  UNITED  STATES  EXPORTS  OF  LEATHER. — 

1908.  1909.  1910. 

Sole-leather  (pounds)    31,189,897  33,002,746  38,332,247 

Value    $6,593,950  $6,887,298  $8,307,880 

Upper  leather — 

Kid,  glazed— value    2,879,969  3,593,909  10,926,255 

Patent  or  enamelled — value 131,154  168,825  367,601 

Splits,  buff,  grain,  and  other  upper 

leathers— value     15,342,497  17,623,525  15,620,336 

All   other  leather    2,004,022  2,159,542  2,192,103 

5.  PRODUCTION  OF  GLUE  AND  GELATINE  IN  DIFFERENT  COUNTRIES. — 

United  States   (Census  of  1905),  50,000  tons,  valued  at  $10,034,685. 
Germany    ( 1901 )'  32,000  tons,  including  2000  tons  of  fine  gelatine. 
England  (1907),  30,850  tons,  valued  at  $2,530,000. 

6.  EXPORTS  OF  GLUE  AND  GELATINE  FROM  THE  UNITED  STATES. — 

1908.  1909.  1910. 

Glue    (pounds)    2,917,173         2,340,426         2,488,205 

Valued   at    $289,441          $244,751          $261,756 


7.  IMPORTS  OF  GLUE  AND  GELATINE  INTO  THE  UNITED  STATES. — 

1908.  1909.  1910. 

Glue  and  gelatine    (pounds)    6,731,943         6,610.894  8,821,554 

Valued  at    $629,032          $655,127  $861.888 


DESTRUCTIVE  DISTILLATION  OF  WOOD.  385 


CHAPTER    XI. 

INDUSTRIES  BASED   UPON  DESTRUCTIVE  DISTILLATION. 

DESTRUCTIVE  distillation  has  been  defined  as  "the  decomposition  of 
a  substance  in  a  close  vessel  in  such  a  manner  as  to  obtain  liquid  pro- 
ducts. ' '  It  must  be  observed  here  that  the  word  product  is  used  to  indi- 
cate something  not  originally  present  in  the  substance  distilled.  A  body 
may  be  obtained  in  the  liquid  distillate  which  has  merely  been  driven 
over  by  heat  and  which  already  existed  in  the  original  material  in  phys- 
ical or  mechanical  admixture.  Such  a  body  is,  to  speak  exactly,  an 
educt  and  not  a  product. 

The  substances  which  are  submitted  to  destructive  distillation  are  in 
the  main  solids,  as  most  classes  of  liquids  are  capable  when  heated  with 
care  of  volatilization  without  decomposition,  although  such  liquids  as 
fatty  oils,  glycerine,  etc.,  are  decomposed  if  distilled  under  normal 
atmospheric  pressure.  (The  cracking  of  petroleum  is  another  illustra- 
tion of  destructive  distillation  of  a  liquid  purposely  brought  about.) 
With  solids,  on  the  other  hand,  it  is  the  exception  rather  than  the  rule 
to  find  one  capable  of  melting  and  vaporizing  unchanged  in  composition 
when  distilled  under  normal  atmospheric  pressure.  The  same  solid, 
moreover,  if  of  at  all  complex  molecular  composition,  may  decompose 
quite  differently  and  yield  different  sets  of  products  according  to  the 
conditions  which  govern  the  distillation.  The  most  important  of  these 
modifying  conditions  is  that  of  temperature.  "Low  temperature  "  dis- 
tillation and  "high  temperature"  distillation  as  practised  upon  the 
same  material  (.wood  or  coal,  for  example)  may  yield  quite  different 
results.  The  physical  condition  or  mechanical  subdivision  of  the  sub- 
stance also  has  an  influence,  although  a  subordinate  one,  upon  the  nature 
of  the  products.  Solids,  upon  the  destructive  distillation  of  which 
important  industries  are  founded,  are  wood,  coal,  shales,  bones,  and 
animal  refuse.  The  distillation  of  shale  has  already  been  considered  in 
connection  with  the  mineral  oil  industry.  (See  p.  28.)  The  other  in- 
dustries will  now  be  noted  in  succession. 

A.  DESTRUCTIVE  DISTILLATION  OF  WOOD. 
I.  Raw  Materials. 

1.  COMPOSITION  OF  WOOD. — The  wood  which  is  to  be  destructively 
distilled  is  composed,  we  may  say  in  general  terms,  of  woody  fibre  and 
plant-juice  or  sap,  which  is  an  aqueous  solution  of  the  substances,  both 
nitrogenous  and  non-nitrogenous,  which  serve  as  the  food  for  the  living 
plant.  The  woody  fibre  is  made  up  primarily  of  cellulose,  which  is  in 
part  changed  into  "lignin,"  as  the  incrusting  substance  is  called.  In 
percentage  composition  this  latter  substance  differs  from  the  pure  cellu- 

25 


386   INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 


lose  in  containing  more  carbon  and  less  oxygen  and  hydrogen.  The 
amount  of  incrusting  material  varies,  being  more  abundant  in  hard  and 
heavy  varieties  than  in  light  and  soft  kinds,  and  wood  which  contains 
it  in  the  largest  proportion  gives  the  most  acid  and  naphtha  on  distilla- 
tion. The  amount  of  water  present  in  wood  also  varies  not  only  accord- 
ing to  the  season  of  the  year,  but  also  quite  widely  in  different  woods 
cut  at  the  same  season.  Thus,  the  following  table  of  Schiibler  and 
Hartig  shows  the  percentage  of  water  of  different  trees  taken  at  the 
period  of  minimum  amount: 


Per  cent,  of  water. 

Beech    18.6 

Willow    26.0 

Maple   27.0 

Elder     28.3 

Ash      28.7 

Birch     30.8 

White  hawthorn 32.3 

Oak   34.7 

White  fir   .  .37.1 


Per  cent,  of  water. 

Horsechestnut 38.2 

Pine    39.7 

Alder    41.6 

Elm     44.5 

Lime   47.1 

Lombardy  poplar 48.2 

La.rch    48.6 

White  poplar    50.6 

Black  poplar 51.8 


2.  EFFECT  OF  HEAT  UPON  WOOD. — The  effect  of  heat  upon  wood  in 
the  absence  of  air  is  a  matter  which  is  to  be  carefully  noted  as  throwing 
light  upon  the  results  obtained  in  destructive  distillation.  It  of  course 
differs  radically  from  the  result  of  heating  with  free  contact  of  air. 
Violette  *  found  that  when  wood  was  carefully  and  slowly  heated  no  de- 
composition occurred  under  150°  C.,  water  only  being  given  off;  between 
150°  and  160°  C.  the  loss  was  two  per  cent,  of  weight  of  the  water-free 
wood;  between  160°  and  170°  C.,  5.5  per  cent.;  between  170°  and  180° 
C.,  11.4  per  cent.,  and  so  on  until  at  280°  C.  63.8  per  cent,  of  volatile 
products  had  been  driven  off  and  36.2  per  cent,  only  of  the  water-free 
wood  remained  in  the  retort.  The  products  given  off  in  this  period  of 
heating  between  150°  and  280°  are  the  valuable  liquid  products  known 
as  pyroligneous  acid  (acetic  acid  and  its  homologues),  wood-naphtha  or 
methyl  alcohol,  methyl  acetate,  acetone,  furfurol,  the  mixture  of  phenols 
known  collectively  as  "wood-creosote,"  and  all  other  bodies  of  empyreu- 
matic  and  tarry  odor.  Above  280°  C.,  the  decomposition  proceeds  some- 
what differently,  hydrocarbons,  both  gaseous  and  liquid,  being  formed. 
The  additional  percentage  of  loss  by  weight  between  280°  and  350°  C. 
is  only  6.5  per  cent,  of  the  water-free  wood,  but  it  makes  from  eighty 
to  ninety  volumes  of  gas.  The  decomposition  continues  from  350°  to 
430°  C.,  when  the  total  loss  by  weight  amounts  to  eighty-one  per  cent, 
of  the  water-free  wood.  The  products  obtained  within  these  limits  of 
temperature  are  largely  solid  hydrocarbons  like  paraffin  and  high  tem- 
perature products  like  benzene  and  toluene,  naphthalene,  phenol  and 
cresol.  From  430°  to  1500°  C.  the  additional  loss  of  weight  is  only  1.7 
per  cent.  We  may  sum  up  these  results  by  saying  that  three  periods 
may  be  distinguished  broadly  for  this  decomposition  of  wood  by  heat: 
first,  from  150°  to  280°  C.,  the  period  of  watery  acid  products;  second, 

*Dingler's  Polytech.   Journal,   123,   117. 


DESTRUCTIVE  DISTILLATION  OF  WOOD.  387 

from  280°  to  350°  C.,  the  period  of  gaseous  products;  and,  third  from 
350°  to  430°  C.,  the  period  of  liquid  and  solid  hydrocarbons.  Violette 
found  also  great  difference  in  the  results  according  as  the  temperature 
was  slowly  raised  or  as  the  wood  was  rapidly  brought  up  to  a  higher 
heat.  Thus,  one  hundred  parts  by  weight  of  wood  slowly  heated  so  that 
the  temperature  of  432°  C.  was  only  reached  after  six  hours  left  18.87 
parts  of  charcoal,  while  one  hundred  parts  of  the  same  wood  put  into  a 
retort  previously  heated  to  432°  C.  left  only  8.96  parts  by  weight  of 
charcoal. 

n.  Processes  of  Manufacture. 

1.  DISTILLATION  OF  THE  WOOD. — The  primitive  method  of  distilling 
wood  devised  by  the  charcoal-burners,  in  which  the  wood  was  piled  up  in 
large  heaps  covered  in  by  clay  and  turf  so  as  to  form  a  circular  dome- 
shaped  mound,  is  still  followed  in  some  heavily- wooded  districts.  Of 
course  the  charcoal  is  the  only  product  sought  in  this  case,  and  the  gase- 
ous and  liquid  products  of  the  distillation  are  allowed  to  escape.  In 
Russia  and  Sweden  the  charcoal-burning  in  mounds  is  now  frequently 
combined  with  the  collection  of  tar,  which  as  it  condenses  is  made  to 
flow  through  inclined  troughs,  and  is  drawn  off  from  below.  In  this 
way  the  valuable  birch-bark  tar  (see  p.  371)  and  kienoel  (Russian  tur- 
pentine oil)  are  obtained.  For  a  proper  collection  of  all  the  products 
of  the  destructive  distillation  of  wood,  however,  it  is  essential  that  the 
distillation  be  carried  out  in  retorts  provided  with  proper  condensation 
apparatus.  These  retorts  may  be  either  set  in  horizontal  or  vertical 
position,  and  may  be  either  fixed  or  capable  of  removal  for  emptying 
and  recharging.  It  is  found  convenient  in  large  works  where  it  is 
desirable  to  carry  on  the  distillation  continuously  to  have  a  series  of 
retorts  connected  with  one  and  the  same  condensation  apparatus  and 
heated  by  the  same  flues.  This  arrangement  allows  of  the  removal  and 
re-charging  of  a  single  retort  without  interrupting  the  working  of  the 
others.  In  recent  years  the  American  and  Canadian  wood  distilling 
plants  have  been  built  with  large  horizontal  retorts  of  such  size  that 
material  in  wagons  of  light  skeleton  construction  can  be  run  in  on  a 
track  prepared  for  them  and  the  wood  distilled  without  having  to  handle 
it  until  completely  changed  to  charcoal.  Several  such  wagons,  each  con- 
taining one  cord  of  wood  cut  to  suitable  length,  are  run  in  one  back  of 
the  other,  and  the  doors  of  the  horizontal  retort  closed  and  locked  tight, 
when  the  heating  is  begun.  When  the  distillation  is  finished  these  cars 
containing  the  glowing  charcoal  are  pushed  from  the  farther  end  of  the 
retort  into  large  cooling  chambers  of  boiler  iron,  where  they  remain 
until  cooled  sufficiently  to  allow  of  their  being  brought  into  the  air 
without  ignition.  The  heating  should  be  conducted  slowly  at  first  so 
that  the  maximum  yield  of  the  low  temperature  products,  acetic  acid 
and  methyl  alcohol,  may  be  obtained,  then  increased  until  the  gas  comes 
off  freely,  and  at  the  end  of  this  stage  of  the  decomposition  again 
strengthened  to  drive  over  the  high  temperature  products  characteristic 
of  the  last  period  of  distillation.  As  the  maximum  temperature  needed 


388   INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 


is  beyond  the  record  of  the  mercury  thermometer,  a  pyrometer  can  be 
used  or  a  small  bar  of  metallic  antimony  which  melts  at  432°  C.  taken 
as  indicator.  Superheated  steam  has  also  been  used  as  a  means  of 
accurately  controlling  the  application  of  heat  in  the  distillation,  and 
it  is  said  that  the  majority  of  European  works  manufacturing  charcoal 
for  gunpowder  purposes  use  this  method  of  distillation.  The  liquid 
which  runs  off.  from  the  condenser  is  at  first  wax-yellow  in  color,  but 
becomes  dark-colored,  reddish-brown,  and  eventually  nearly  black  and 
quite  turbid.  When  allowed  to  stand  at  rest  it  soon  separates  in  two 
sharply  distinct  layers, — the  lower  one  of  a  thick  tar,  dark  or  perfectly 
black  in  color,  and  the  upper  one,  which  is  much  the  larger  in  amount, 
is  the  crude  pyroligneous  acid  and  is  reddish-yellow  or  reddish-brown 
in  color.  A  light  film  of  oil  often  covers,  in  part  at  least,  this  watery 
layer  and  represents  the  benzene  hydrocarbons  produced.  We  have 
already  noted  the  fact  that  the  yield  of  liquid  products  is  affected 
greatly  by  the  temperature  used  for  distillation.  Different,  varieties  of 
wood  also  vary  somewhat  in  the  results  obtained,  even  when  distilled 
under  the  same  conditions  of  temperature.  This  is  illustrated  in  the 
following  few  examples :  * 


Charcoal. 

Tar. 

Crude  pyro- 
ligneous 
acid. 

Containing 
actual  acid. 

Gases. 

T>  ^  v      i,  f  slowly  heated  . 
Kedbeech{  rapidly  heated     .    .    . 
•D-    v.   f  slowly  heated  . 

26.7 
21.9 
29.2 
21.5 
34.7 
27.7 
30.3 
24.2 

5.9 
4.9 
5.5 
3.2 
3.7 
3.2 
4.4 
9.8 

45.8 
39.5 
45.6 
39.7 
44.5 
42.0 
41.0 
42.0 

5.2 
3.9 
5.6 
4.4 
4.1 
3.4 
2.7 
2.4 

21.7 
33.8 
19.7 
35.6 
17.2 
27.0 
24.4 
24.1 

Birch  \rapidly  heated     

^  i    f  slowly  heated  . 

'    \  rapidly  heated     

-p.         (  slowly  heated  

'    \  rapidly  heated  

Beech-wood  and  foliage  trees  in  general  yield  distinctly  more  acid 
than  coniferous  trees,  but  the  latter  yield  more  tar  of  terebinthinate  char- 
acter. The  figures  given  above,  it  must  be  remembered,  however,  were 
gotten  in  experiments  with  small  portions.  In  practice,  working  with 
larger  quantities,  the  yield  of  several  of  the  products  is  notably  larger. 
The  yield  of  wood-spirit,  or  methyl  alcohol,  varies  from  five-tenths  to 
one  per  cent,  of  the  weight  of  the  dry  wood. 

The  emptying  of  the  retorts,  if  done  as  intended  while  the  charcoal 
is  yet  glowing,  involves  the  use  of  air-tight  pits  into  which  the  charcoal 
can  be  emptied  from  the  retorts  and  immediately  covered  with  moist 
charcoal-powder  to  prevent  loss  by  combustion.  A  form  of  apparatus 
for  distilling  the  sawdust  so  abundantly  produced  in  wood-working 
processes  has  been  devised  by  Halliday,  of  Salford,  England,  and  is 
said  to  work  satisfactorily  in  practice.  It  is  shown  in  Fig.  98.  It  con- 
sists of  a  horizontally  placed  cylindrical  retort,  A,  within  which  revolves 
an  endless  screw,  B.  The  sawdust  is  regularly  fed  in  through  the 
vertical  pipe  C,  and  falling  upon  the  screw  is  kept  moving  at  a  uniform 

*  Ost,  Lehrbuch  der  technische  Chemie,  p.  294. 


DESTRUCTIVE  DISTILLATION  OF  WOOD. 


389 


speed  along  the  entire  length  of  the  heated  retort.  At  the  farther  end 
the  vapors  and  gaseous  products  of  the  distillation  escape  through  an 
ascending  pipe,  K,  leading  to  the  condenser,  while  the  powdered  charcoal 
drops  through  the  pipe  D  into  water,  where  it  is  at  once  quenched. 

A  general  view  of  the  products  of  the  distillation  of  wood  and  their 
subsequent  treatment  is  given  in  the  accompanying  diagram  taken  from 
Post.* 

2.  TREATMENT  AND  PURIFICATION  OF  THE  CRUDE  WOOD-VINEGAR. — 
The  brown  aqueous  solution  poured  off  from  the  tarry  layer  (see  above) 
has  a  strong  empyreumatic  odor,  and  contains,  besides  the  acetic  acid, 


FIG.  98 


methyl  alcohol,  acetone,  and  homologous  ketones,  allyl  alcohol,  homo- 
logues  of  acetic  acid  (such  as  formic,  propionic,  butyric,  and  valerianic 
acids),  methyl  acetate,  acetate  of  ammonia  and  of  methylamine,  alde- 
hyde, furfurol,  phenols,  and  other  empyreumatic  and  tarry  bodies.  It 
is  not  used  in  its  crude  condition  except  in  the  preparation  of  the  crude 
pyrolignite  of  iron  (iron-liquor}  or  in  limited  amount  for  impregnating 
wood.  The  first  step  towards  purification  is  to  separate  the  wood- 
naphtha  (the  fraction  containing  the  methyl  alcohol,  acetone,  and  methyl 
acetate)  from  the  wood-vinegar  (crude  acetic  acid),  which  is  done  by 
distillation.  Two  procedures  are  possible  here.  Either  to  neutralize 
the  crude  pyroligneous  acid  with  milk  of  lime  and  then  distil  off  the 
volatile  constituents  only,  using  an  iron  still,  or  to  distil  the  crude  pyro- 

*Post,  Chem.  Technologie,  p.  78. 


390     INDUSTRIES  BASED   UPON  DESTRUCTIVE  DISTILLATION. 


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DESTRUCTIVE  DISTILLATION  OF  WOOD.  391 

ligneous  acid  from  a  copper  still  without  neutralizing  with  lime.  In  the 
former  case,  while  the  wood-naphtha  distils  off,  the  tarry  impurities  of 
the  crude  pyroligneous  acid  remain  with  the  lime  salt  in  the  still,  and  on 
evaporation  a  dark  mass  is  obtained  known  as  "brown  acetate  of  lime." 
In  the  latter  case,  after  catching  the  wood-naphtha  distillate,  the  receiver 
is  changed  and  the  crude  acetic  acid  is  also  collected  freed  to  a  con- 
siderable extent  from  the  tarry  matter,  so  that  on  neutralizing  with  milk 
of  lime  and  evaporating  the  product  is  a  lighter  salt  known  as  "gray 
acetate  of  lime. ' '  The  latter  process  is  now  more  generally  in  use.  The 
solution  of  the  calcium  acetate  is  evaporated  in  iron  pans;  the  phenols 
and  tarry  products  which  volatilized  with  the  acetic  acid  separate  largely 
as  scum  and  may  be  skimmed  off,  so  that  the  residue  of  the  evaporation 
is  much  purer  than  the  product  of  the  other  method  mentioned  above. 

If  the  brown  acetate  of  lime  has  been  obtained  and  is  to  be  further 
worked  for  acetic  acid,  it  is  found  necessary  to  roast  it  at  a  temperature 
not  exceeding  250°  C.  so  as  to  drive  off  as  much  of  the  tarry  impurity 
as  possible  without  decomposing  any  of  the  acetate.  If,  on  the  other 
hand,  the  gray  acetate  is  taken,  it  is  distilled  from  copper  retorts  with 
concentrated  aqueous  hydrochloric  acid,  taking  care  to  avoid  an  excess. 
The  acetic  acid  distils  over  between  100°  and  120°  C.,  is  clear  in  color 
and  has  only  a  slight  empyreumatic  odor.  Its  specific  gravity  usuall}7 
ranges  from  1.058  to  1.061,  and  it  contains  about  fifty  per  cent,  of  pure 
acetic  acid.  If  some  water  is  added  with  the  hydrochloric  acid  so  that 
the  distilled  acetic  acid  is  more  dilute,  it  tends  to  give  a  purer  product, 
as  the  liberated  acetic  acid  cannot  decompose  any  of  the  calcium  chloride 
before  coming  over.  A  good  proportion  is  said  to  be  one  hundred  parts 
of  acetate  of  lime,  ninety  to  ninety-five  of  hydrochloric  acid  of  1.160 
specific  gravity,  and  twenty-five  parts  of  water.  The  acetic  acid  so 
obtained  has  a  slight  empyreumatic  odor.  It  may  be  freed  from  this  by 
distilling  with  from  two  to  three  per  cent,  of  potassium  bichromate,  or 
by  filtration  through  freshly  ignited  wood  charcoal. 

The  brown  acetate  of  lime  usually  contains  about  sixty-eight  to 
sixty-nine  per  cent,  of  pure  acetate,  while  the  gray  acetate  contains  from 
eighty-five  to  eighty-six  per  cent,  of  true  acetate. 

In  recent  years  it  has  been  found  practicable  to  prepare  pure  acetic 
acid  from  the  crude  pyroligneous  acid  by  making  the  sodium  salt  in- 
stead of  the  lime  salt.  The  sodium  salt  allows  of  purifying  by  recrys- 
tallization,  and  can  also  be  fused  without  decomposition.  Glacial  acetic 
acid  is  generally  made  by  distilling  the  anhydrous  and  fused  sodium 
acetate  with  concentrated  sulphuric  acid. 

Rohrmann  has  recently  developed  a  process  by  which  it  is  possible 
to  make  ninety  per  cent,  or  even  glacial  acetic  acid  direct  from  the  crude 
acetate  of  lime  in  one  operation.  He  uses  a  column  still  provided  with 
Lunge-Rohrmann  plates,  over  which  concentrated  sulphuric  acid  is  made 
to  trickle.  This  meets  the  ascending  acetic  vapors  and  dehydrates  them. 
They  pass  over  into  a  condenser,  while  the  empyreumatic  vapors  are 
drawn  off  by  a  warm-air  current  which  connects  with  the  column.  When 
hydrochloric  acid  is  used  to  decompose  the  acetate  the  resulting  acetic 


392   INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

acid  can  be  brought  to  eighty  per  cent. ;  when  sulphuric  acid  is  used, 
one  hundred  per  cent,  acid  can  be  obtained. 

3.  PURIFICATION  OF  THE  CRUDE  WOOD-SPIRIT. — The  wood-spirit  forms 
the  first  fraction  when  the  crude  pyroligneous  acid  is  distilled,   and 
amounts  to  perhaps  one-sixth  of  the  latter  in  bulk.    It  is  usual  to  collect, 
however,  until  the  hydrometer  reading  of  the  distillate,  which  begins  at 
about  .900,  has  risen  to  1.000  or  a  little  beyond.    This  distillate  forms  a 
greenish-yellow  liquid  of  unpleasant  odor  and  contains  many  impurities 
besides  the  acetone  and  methyl  acetate,  the  chief  substances  which  are 
present  with  the  methyl  alcohol.    Milk  of  lime  is  first  added  and  allowed 
to  stand  with  the  liquid  for  several  hours.    The  mixture  heats  up  quite 
distinctly  as  the  lime  combines  with  any  free  acid  and  begins  to  decom- 
pose the  methyl  acetate  and  other  ethereal  compounds  of  acetic  acid, 
small  quantities  of  ammonia  often  being  given  off.     It  is  then  distilled 
by  connecting  it  with  a  column  rectifying  apparatus.      (See  p.  244.) 
The  distillate  thus  obtained,  of  about  .816  specific  gravity,  is  colorless 
at  first  but  gradually  darkens  in  color,  and  if  diluted  with  water  becomes 
milky  from  separated  oily  hydrocarbons  and  ketones.     It  is  therefore 
diluted  down  with  water  to  about  .935  specific  gravity  and  allowed  to 
stand  until  this  oily  impurity  rises  to  the  top  in  a  distinct  layer.     The 
diluted  spirit  is  again  distilled  over  lime  once  or  twice  with  a  rectifying 
column  and  so  brought  to  ninety-eight  or  ninety-nine  per  cent,  strength. 
The  acetone  impurity,  however,  is  not  removed  by  any  of  these  rectifica- 
tions, as  the  boiling-points  of  acetone   (56.4°   C.)    and  methyl  alcohol 
(55.1°  C.)   do  not  allow  of  their  separation  in  this  way.     To  remove 
the  acetone  a  number  of  methods  have  been  proposed.    The  methyl  alcohol 
may  be  converted  into  the  solid  chloride  of  calcium  compound,  or  the 
oxalate  of  methyl  and  the  acetone  having  been  removed  by  careful  heat- 
ing, the  methyl  compound  is  decomposed  by  water  or  alkali.     Or  the 
methyl  alcohol  is  distilled  over  chloride  of  lime,  which  reacts  with  the 
acetone  to  form  chloroform.    The  passing  in  of  chlorine  in  order  to  con- 
vert the  acetone  into  high-boiling  chloracetones,  which  are  then  separated 
from  the  methyl  alcohol  by  distillation,  has  also  been  proposed. 

4.  TREATMENT  OF  THE  WOOD-TAR. — The  tar  wrhich  has  separated  from 
the  crude  pyroligneous  acid  by  settling,  and  that  which  has  risen  and 
been  skimmed  off  in  the  neutralizing  of  the  acid,  are  united  and  sub- 
mitted to  distillation  in  horizontally-placed  iron  retorts,  which  are  set  at 
a  slight  inclination.     At  first  acid-water  comes  over,  then  light  oils, 
and  finally  heavy  oils  until  no  more  will  distil.    The  pitchy  residue  is  run 
out  while  hot,  so  that  it  does  not  adhere  to  the  walls  of  the  retort.    The 
relative  amounts  of  the  several  fractions  from  the  tar  depend  upon  the 
nature  of  the  wood  used  in  the  original  distillation  and  upon  the  way 
that  distillation  has  been  carried  out.     Hard  woods  usually  give  a  tar 
which,  according  to  Vincent,  when  redistilled  yields  as  follows: 

Aqueous  distillate  (wood-spirit  and  pyroligneous  acid)  .  .10  to  20  per  cent. 
Lighter  oily  distillate    (specific  gravity  .966  to  .977...  10  to  15     "       " 

Heavy  oily  distillate  (specific  gravity  1.014  to  1.021)  ...  15     "  ," 

Pitch  ..50  to  65     "       " 


DESTRUCTIVE  DISTILLATION  OF  WOOD.  393 

The  oily  distillates  are  washed  with  weak  soda  to  remove  adhering 
acid  and  £hen  carefully  rectified,  when  the  oils  coming  over  under  150°  C. 
are  collected  for  solvent  and  varnish-making  purposes,  those  between 
150°  and  250°  C.  collected  as  creosote  oils,  and  those  above  250°  C.  used 
for  burnings  oils. 

The  creosote  oil,  which  is  the  most  valuable  part,  is  thoroughly  agi- 
tated with  strong  caustic  soda  solution,  the  aqueous  layer  drawn  off, 
mixed  with  sulphuric  acid,  and  allowed  to  stand  for  a  time  at  rest,  when 
the  creosote  oil  separates  out.  This  is  best  driven  off  by  steam  distilla- 
tion and  again  rectified  finally  from  glass  retorts. 

Stockholm  tar,  so  largely  used  in  ship-building,  is  the  product  of  a 
rude  distillation  of  the  resinous  wood  of  the  pine. 

North  Carolina  pine-tar  is  also  the  product  of  a  distillation  of  the 
pine.  The  billets  of  pine- wood  are  piled  in  heaps  like  a  charcoal-burner's 
mound,  though  not  so  large,  covered  in  with  clay  and  turf,  and  lighted 
from  the  top.  The  resin  or  tar  distils  downward  and  runs  off  through 
inclined  troughs  previously  fixed  for  it.  It  is  obvious  that  the  compo- 
sition of  both  the  Stockholm  and  the  North  Carolina  tar  differs  notably 
from  that  of  wood-tar  distilled  in  retorts  from  hard  woods.  This  com- 
position will  be  referred  to  later. 

m.  Products. 

1.  PYROLIGNEOUS  ACID  AND  PRODUCTS  THEREFROM. — The  crude  acid 
as  obtained  in  the  distillation  is  a  clear  liquid  of  reddish-brown  color 
and  strong  acid  taste,  with  a  peculiar  penetrating  odor  described  as 
empyreumatic,  and  now  known  to  be  due  largely  to  the  furfurol  it  con- 
tains.   It  possesses  a  specific  gravity  of  from  1.018  to  1.030  and  contains 
from  four  to  seven  per  cent,  of  real  acetic  acid.    Pyrolignite  of  iron  (iron 
or  black  liquor)  is  a  solution  of  ferrous  acetate  with  some  ferric  acetate, 
prepared  by  acting  upon  scrap-iron  with  crude  pyroligneous  acid.     It 
forms  a  deep-black  liquid,  and  is  concentrated  by  boiling  to  1.120  specific 
gravity,  when  it  contains  about  ten  per  cent,  of  iron.    It  is  extensively 
used  by  calico-printers.     Brown  and  gray  acetate  of  lime  have  been 
already  referred  to.     Other  technically  important  acetates  are  lead  ace- 
tate (sugar  of  lead),  used  in  the  preparation  of  the  alum  mordants  and 
the  lead  pigments;  copper  acetate,  the  basic  salt  of  which  is  known  as 
"verdigris;"  aluminum  acetate,  the  solution  of  which  is  used  in  calico- 
printing  under  the  name  of  ' '  red  liquor. ' ' 

Pure  acetic  acid  is  a  colorless  acid  liquid  with  pungent  smell  and 
taste.  It  crystallizes  when  chilled  in  large  transparent  tablets,  melting 
at  16.7°  C.,  whence  the  name  "glacial  acetic  acid."  Its  specific  gravity 
at  15°  C.  is  1.0553,  and  it  boils  under  normal  pressure  at  119°  C. 

2.  METHYL  ALCOHOL  AND  WOOD-SPIRIT. — As  before  stated,  crude  wood- 
spirit  is  a  complex  liquid  and  contains  many  impurities.     The  percent- 
age of  real  methyl  alcohol  may  rise  to  ninety-five  per  cent.,  but  more 
generally  ranges  from  seventy-five  to  ninety  per  cent.     Some  impure 
wood-naphthas  go  much  lower,  however,  than  this.    A  large  percentage 
of  acetone  does  not  interfere  with  its  use  as  a  solvent  for  resins  and  for 


394  INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

varnish-making,  but  does  interfere  with  its  use  in  the  aniline-color  in- 
dustry, where  a  very  pure  methyl  alcohol  is  needed  for  the  manufacture 
of  dimethyl  aniline.  The  methods  of  freeing  methyl  alcohol  from  the 
two  chief  impurities,  methyl  acetate  and  acetone,  have  already  been 
referred  to.  Pure  methyl  alcohol  has  a  purely  spiritous  odor,  a  specific 
gravity  of  .7995  at  15°  C.,  and  boils  at  55.1°  C.  It  is  miscible  in  all 
proportions  with  water,  ordinary  alcohol,  and  ether. 

3.  ACETONE. — This  substance  is  of  interest  as  always  produced  in  the 
distillation  of  wood,  and  hence  present  in  the  crude  wood-spirit.     The 
acetates  yield  it  as  the  chief  product  when  submitted  to  dry  distillation, 
and  the  vapors  of  acetic  acid  distilled  over  porous  baryta  at  a  tempera- 
ture of  from  350°  C.  to  400°  C.,  it  has  been  found  by  Dr.  Squibb,  will 
also  readily  yield  acetone.     One  hundred  kilos,  of  forty  per  cent,  acid 
will  give  from  twelve  to  thirteen  kilos,  of  acetone.    At  present  it  is  made 
on  a  large  scale  by  distilling  the  gray  acetate  of  lime  in  iron  stills  pro- 
vided with  mechanical  agitation  at  a  temperature  of  about  290°    C. 
When  purified,  it  is  a  colorless  liquid  of  peculiar  ethereal  odor  and  burn- 
ing taste,  and,  like  methyl  alcohol,  is  miscible  in  all  proportions  with 
ether,  alcohol,  and  water.     It  is  an  excellent  solvent  for  resins,  gums, 
camphors,  fats,  and  pyroxyline,  or  gun-cotton.    It  does  not  form  a  com- 
pound with  dry  calcium  chloride  and  can  thus  be  separated  from  methyl 
alcohol  when  in  admixture  with  this  latter.     Chlorine  and  iodine  in  the 
presence  of  an  alkali  react  with  acetone  to  form  chloroform  and  iodoform. 

4.  CREOSOTE. — Wood-tar    creosote    is    a   strongly    refracting    liquid, 
which  is  colorless  when  freshly  distilled  but  gradually  acquires  a  yellow 
or  brown  color.    It  has  a  smoky  aromatic  odor,  which  is  very  persistent 
and  is  quite  distinct  from  that  of  carbolic  acid.    It  has  a  specific  gravity 
ranging  from  1.030  to  1.080,  and  boils  between  205°  and  220°  C.    It  is 
a  powerful  antiseptic,  and  is  largely  used  to  preserve  meats,  etc.  It 
differs   from   coal-tar  creosote   in   containing   relatively   little    common 
phenol  (carbolic  acid)  and  relatively  large  amounts  of  higher  phenols, 
such  as  phlorol,  C8H9.OH,  guaiacol,  C7H7O.OH,  and  creosol,  C8H9O.OII. 

5.  PARAFFIN. — This  mixture  of  solid  hydrocarbons,  as  already  said, 
occurs  in  the  higher  boiling  distillate  gotten  from  wood.    It  is  of  interest 
to  recall  that  paraffin  was  first  discovered  by  Reichenbach  in  beech-wood 
tar.     At  present,  however,  the  extraction  of  paraffin  from  wood-tar  is 
not  to  be  thought  of  because  of  the  cheapness  of  its  production  from 
petroleum  and  bituminous  shales.     It  has  been  already  described  under 
the  chapter  on  Petroleum.     (See  p.  33.) 

6.  CHARCOAL. — We  have  already  shown  in  the  table  of  results  of 
slow  and  rapid  distillation  of  wood  (see  p.  388)  that  the  relative  amount 
of  charcoal  depends  upon  the  manner  of  heating,  being  larger  with 
gradual  application  of  heat  and  smaller  with  rapicj.  heating.    The  proper- 
ties and  chemical  composition  of  the  charcoal  are  similarly  dependent 
upon  the  temperature  to  which  the  wood  is  heated.    Wood  is  stated  to 
become  brown  at  220°  C.,  at  280°  C.  it  becomes  a  deep  brownish.-bla.ck 
and  begins  to  be  friable,  and  at  310°  C.  forms  an  easily  friable  black 
mass  taking  fire  easily.    That  prepared  at  higher  temperatures  is  harder 
and  less  readily  ignited,  and  it  eventually  becomes  graphitic  and  rings 


DESTRUCTIVE  DISTILLATION  OF  WOOD. 


395 


with  a  metallic  sound  when  struck.  The  accompanying  table  from  Vio- 
lette  shows  the  gradual  change  in  the  composition  of  charcoal  prepared 
at  different  temperatures  from  the  same  kind  of  wood  (buckthorn) : 


Heated  to 

Carbon, 
per  cent. 

Hydrogen, 
per  cent. 

Oxygen,  nitro- 
gen, and  loss. 

Ash, 
per  cent. 

Dry  wood  

150°  C. 

47.51 

6.12 

46.29 

0.08 

Charred  wood   

260°  C. 

67  85 

5.04 

26.49 

0.56 

lied  charcoal  

280°  C. 

72.64 

4.70 

22.10 

0.57 

Brown  charcoal    .... 

320°  C. 

73.57 

4.83 

21.09 

0.52 

Dull  black  charcoal  .    .    . 

340°  C. 

75.20 

4.41 

19.96 

0.48 

Lustrous  black  charcoal  . 

432°  C. 

81.64 

1.96 

15.25 

1.16 

Extreme  white  heat     .    . 

1500°  C. 

96.52 

0.62 

0.94 

1.95 

IV.  Analytical  Tests  and  Methods. 

1.  ASSAY  OF  PYROLIGNEOUS  ACID  AND  CRUDE  ACETATES. — The  crude 
pyroligneous  acid,  as  before  stated,  contains  from  four  to  seven  per  cent, 
of  real  acetic  acid.     Its  strength  may  be  ascertained  by  titration  with 
standard  alkali,  using  phenol-phthalein  as  an  indicator.    If  the  liquid  is 
too  dark  to  allow  of  the  end  reaction  being  readily  seen,  it  can  be  diluted 
sufficiently,  as  the  reaction  will  still  be  sufficiently  delicate.     In  the 
absence  of  sulphates  in  the  sample,  the  acetic  acid  can  be  determined 
by  adding  excess  of  pure  precipitated  barium  carbonate  to  the  solution, 
filtering,  and  determining  the  barium  in  the  nitrate  by  the  aid  of  sul- 
phuric acid. 

As  the  pyroligneous  acid  is  largely  converted  into  calcium  acetate  in 
th.e  process  of  purifying,  the  analysis  of  the  brown  or  gray  acetate  of 
lime  as  a  common  cemmercial  product  becomes  of  some  importance.  This 
commercial  acetate  may  contain  from  sixty-five  to  eighty  per  cent,  of 
true  acetate  of  lime,  with  carbonate  of  lime,  so-called  "tar-lime,"  and 
empyreumatic  matter  as  chief  impurities.  The  acetic  acid  determination 
may  be  made  by  different  methods,  but  the  most  accurate  according  to 
the  experience  of  the  author  is  the  distillation  method,  as  suggested  by 
Stillwell  and  Gladding.  One  gramme  of  the  sample  of  acetate  of  lime  is 
placed  in  a  small  distillation  bulb  or  flask  with  a  long  neck,  a  little 
distilled  water  added,  and  then  a  solution  of  five  grammes  of  glacial 
phosphoric  acid  dissolved  in  ten  cubic  centimetres  of  water.  The  flask 
is  then  heated  to  distil  off  the  acetic  acid,  care  being  taken  to  avoid 
spurting  and  mechanical  carrying  over  of  any  of  the  phosphoric  acid. 
When  the  contents  have  nearly  gone  to  dryness,  some  twenty-five  cubic 
centimetres  of  distilled  water  are  introduced  and  the  distillation  re- 
peated. If  this  is  done  some  three  or  four  times,  the  distillate  will  be 
found  to  be  free  from  -acid  reaction.  The  combined  distillate  is  then 
brought  to  definite  volume  and  titrated  with  decinormal  soda  solution, 
using  phenol-phthalein  as  indicator. 

2.  DETERMINATION    OF    METHYL   ALCOHOL    IN    COMMERCIAL   WOOD- 
SPIRIT. — But  one  method,  and  that  not  capable  of  the  most  accurate 
working,  is  at  present  available.    Five  cubic  centimetres  of  the  sample 


396   INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

of  wood-spirit  are  allowed  to  drop  slowly  upon  fifteen  grammes  of  phos- 
phorus di-iodide  placed  in  a  small  flask  of  some  thirty  cubic  centimetres 
capacity.  This  is  connected  with  an  inverted  condenser  and  cooled  exter- 
nally while  the  reaction  takes  place.  Five  cubic  centimetres  of  a  solu- 
tion of  one  part  iodine  in  one  part  of  hydrogen  iodide  of  1.7  specific 
gravity  is  then  added  and  the  mixture  gently  digested  for  a  quarter  of 
an  hour,  when  the  condenser  having  been  turned  downward  the  iodide 
of  methyl  formed  is  distilled  off.  It  is  collected  in  a  graduated  tube 
divided  into  one-tenth  cubic  centimetres,  washed  with  some  fifteen  cubic 
centimetres  of  water  with  vigorous  agitation,  allowed  to  settle,  and  the 
volume  read  off.  Five  cubic  centimetres  of  pure  and  perfectly  dry 
methyl  alcohol  should  give  7.45  cubic  centimetres  of  iodide  of  methyl. 

3.  DETERMINATION  OF  THE  ACETONE  IN  COMMERCIAL  WOOD-SPIRIT. — 
This  may  be  done  by  either  the  Kraemer  and  Grodzki  gravimetric  method 
or  the  Messinger  volumetric  method,  both  of  which  depend  upon  its 
quantitative  conversion  in  the  presence  of  iodine  and  caustic  alkali  into 
iodoform.     In  the  former  case,  one  cubic  centimetre  of  the  sample  of 
wood-spirit  is  mixed  with  ten  cubic  centimetres  of  a  double  normal 
solution  of  caustic  soda  (eighty  grammes  to  the  litre),  and  to  the  mixture, 
after  thorough  agitation,  is  added  five  cubic  centimetres  of  a  solution 
containing  two  hundred  and  fifty-four  grammes  of  iodine  and  three 
hundred  and  thirty-two  grammes  of  potassium  iodide  to  the  litre.     The 
iodoform  which  separates  on  agitation  is  dissolved  by  the  addition  of  ten 
cubic  centimetres  of  ether  free  from  alcohol.    An  aliquot  portion  of  the 
ethereal  layer  is  then  pipetted  off  into  a  tared  watch-crystal,  and  the  iodo- 
form  remaining   after   evaporation   is   weighed.      Three    hundred    and 
ninety-four  parts  of  iodoform  correspond  to  fifty-eight  parts  of  acetone. 
More  accurate  is  the  Messinger  volumetric  process.    In  this,  twenty  cubic 
centimetres  (or  thirty  cubic  centimetres  in  samples  rich  in  acetone)  of 
normal  potash  solution  and  one  or  two  cubic  centimetres  of  the  wood- 
spirit  in  question  are  shaken  together  in  a  stoppered  250-cubic-centi- 
metre  flask  and  a  known  quantity  (twenty  or  thirty  cubic  centimetres) 
of  a  one-fifth  normal  iodine  solution  added.     The  mixture  is  shaken 
until  the  supernatant  liquid  clears  perfectly  on  momentary  standing, 
hydrochloric  acid  of  1.025  specific  gravity  is  added  in  amount  equal  to 
the  potash  solution  before  used,  and  excess  of  decinormal  sodium  tliio- 
sulphate  run  in.     Starch  paste  is  then  added,  and  the  excess  of  sodium 
thiosulphate  titrated  with  one-fifth  normal  iodine  solution.     If  r  be  the 
volume  in  cubic  centimetres  of  the  iodine  solution  required  to  combine 
with  the  acetone,  and  n  the  volume  in  cubic  centimetres  of  the  methyl 
alcohol  taken,  then  the  quantity  of  acetone  by  weight  in  one  hundred 

, .  r  X  .193345 

cubic  centimetres  of  the  sample  is  equal  to 

n 

4.  QUALITATIVE  TESTS  FOR  WOOD-TAR  CREOSOTE. — The  U.  S.  Pharma- 
copoeia gives  the  following  tests  as  enabling  one  to  distinguish  between 
wood-tar  creosote  and  coal-tar  creosote : 

1.  On  stirring  together  equal  volumes  of  wood-tar  creosote  and  collo- 
dion in  a  dry  test-tube  no  permanent  coagulation  should  form. 


DESTRUCTIVE  DISTILLATION  OF  COAL.  397 

2.  If  one  volume  of  creosote  be  mixed  with  one  volume  of  ninety-five 
per  cent,  glycerine,  a  clear  mixture  will  result  from  which  a  creosotic  layer 
equal  to  or  greater  in  volume  than  the  creosote  employed  will  separate 
on  the  addition  of  one-fourth  volume  of  water. 

3.  On  adding  to  ten  cubic  centimetres  of  a  saturated  aqueous  solu- 
tion of  creosote  one  drop  of  ferric  chloride  test  solution,  the  liquid 
develops  a  clear  violet-blue  color,  which  is  very  transient ;   it  then  clouds 
almost  instantly,  the  color  passing  rapidly  from  a  grayish-green  into  a 
muddy-brown,  with  finally  the  formation  of  a  brown  precipitate. 

4.  If  one  cubic  centimetre  of  creosote  be  cautiously  and  gently  shaken 
with  two  cubic  centimetres  of  petroleum  benzine  and  two  cubic  centi- 
metres of  freshly-prepared  barium  hydroxide  solution -until  a  uniform 
mixture  is  produced,  upon  complete  separation  three  distinct  layers  are 
visible,  the  middle  one  of  which  contains  the  creosote,  unaltered  in  ap- 
pearance ;  while  the  petroleum  benzine  should  not  be  blue  or  muddy  and 
the  aqueous  layer  should  not  have  acquired  a  red  tint  (absence  of  coeru- 
lignol  and  other  high-boiling  constituents  of  wood-tar). 

B.  DESTRUCTIVE  DISTILLATION  OF  COAL. 
I.  Raw  Materials. 

Probably  the  most  important  industry  involving  the  destructive  dis- 
tillation of  coal  is  the  manufacture  of  illuminating  gas.  The  classes  of 
coals  employed  for  the  purpose  are  confined  to  those  varieties  which 
are  bituminous  in  their  nature,  yielding  when  distilled  volatile  hydro- 
carbons in  varying  quantity.  The  uncombined  or  "fixed  carbon,"  with 
the  mineral  constituents  originally  present  in  the  coal,  remaining,  after 
the  distillation  comprise  coke. 

Bituminous  Coals  have  the  property,  not  possessed  by  the  anthra- 
cites, of  softening  and  apparently  fusing  when  subjected  to  a  tempera- 
ture below  that  at  which  combustion  would  take  place.  This  fusion 
indicates  the  commencement  of  destructive  distillation,  when  both  solid, 
liquid,  and  gaseous  carbon  compounds  are  formed.  Bituminous  coal  is 
essentially  a  coking  coal,  and  as  such  is,  to  a  very  great  extent,  employed 
in  the  coking  regions  of  Western  Pennsylvania.  It  is  black  or  grayish- 
black  in  color,  of  a  resinous  lustre,  and  somewhat  friable,  being  easily 
broken  into  cubical  fragments  of  more  or  less  regularity;  upon  ignition 
it  burns  with  a  yellow  flame.  When  it  is  heated  to  bright  redness  in 
retorts  or  ovens,  free  from  the  access  of  air,  the  volatile  matter,  before 
mentioned,  carbon  compounds  of  hydrogen  and  of  oxygen,  with  water, 
pass  off.  Coals  having  a  large  percentage  of  hydrogen  will  yield  more 
volatile  substances  at  the  temperature  of  distillation  and  less  carbona- 
ceous residue  than  others  which  may  contain  less  hydrogen  and  more 
carbon, — approaching  anthracite  in  composition. 

Coking  and  Non-coking  Coals  are  quite  similar  in  chemical  composi- 
tion ;  the  coking  varieties  contain  less  volatile  matter,  however,  than  the 
non-coking;  the  latter  do  not  possess  the  property  of  fusing  to  a  com- 
pact "coky"  mass,  but  retain  their  original  form,  and  yield  a  coke  which 


398   INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 


has  no  commercial  value  unless  it  is  obtained  from  large  pieces  of  the 
coal. 

Cannel  Coal  is  much  more  compact  than  gas  or  coking  coals,  duller 
in  appearance,  possessing  a  grayish-black  to  brown  color,  and  burning 
with  a  clean  candle-like  flame.  It  does  not  soil  the  hands,  and  is  not 
readily  fractured.  It  is  capable  of  taking  a  high  polish,  and  can  be  cut 
or  turned  into  articles  for  use  or  ornamentation.  Cannel  coal  occurs  in 
large  quantities  in  West  Virginia,  and  near  Glasgow,  Scotland,  in  Lan- 
cashire, England,  and  at  other  localities.  Destructively  distilled,  it- 
yields  a  larger  amount  of  volatile  matter  and  ash,  with  much  less  coke, 
than  the  bituminous  coals. 

Brown  Coal,  or  Lignite,  appears  to  occupy  an  intermediate  position 
between  the  bituminous  coals  and  wood.  It  retains  the  ligneous  struc- 
ture of  the  material  from  which  it  is  formed, — hence  the  name  Lignite. 
The  vegetable  remains  in  a  great  many  cases  are  quite  distinct.  The 
color  varies  from  yellowish-brown  in  the  earthy,  to  black  in  the  more 
compact,  coal-like  varieties.  The  percentage  of  carbon  contained  is  low, 
fifty  to  eighty  per  cent.,  though  rarely  exceeding  seventy  per  cent.,  while 
the  hydrogen  is  from  4  to  6.85  per  cent.  Oxygen  and  nitrogen  are 
present  in  variable  quantities  from  7.59  to  36.1  per  cent.  The  ash  in 
good  qualities  is  low,  in  earthy  specimens  is  high,  in  many  cases  exceed- 
ing fifty  per  cent.  Lignite  does  not  yield  coke.  Aside  from  being 
utilized  as  fuel  in  the  several  localities  where  it  is  found,  for  both 
domestic  and  industrial  purposes,  it  has  been  distilled  for  volatile  con- 
stituents in  Saxony. 

Peat,  or  Turf,  occurring  in  large  areas  in  Ireland  and  in  some  parts 
of  Europe,  consists  of  the  decayed  remains  of  certain  forms  of  plants. 
It  has  been,  according  to  Mills,  destructively  distilled  for  tarry  prod- 
ucts, the  industry,  however,  being  no  longer  profitable. 

The  following  tables,  taken  from  the  Reports  of  the  Second  Geological 
Survey  of  Pennsylvania,  show  the  analyses  of  some  of  the  more  im- 
portant varieties  of  American  gas  coals,  coking  coals,  and  non-coking, 
or  block  coals. 

I.    Gas  Coals. 


WESTMORELAND  COAL  COMPANY. 

PENNSYLVANIA  GAS  COAL  COMPANY. 

South  Side 
Mine. 

Foster 
Mine. 

Larrimer, 
No.  2. 

Irwin, 
No.  1. 

Irwin, 
No.  2. 

Sewickley. 

Water  at  225°  .  . 
Volatile  matter  . 
Fixed  carbon.  . 
Sulphur  .... 
Ash  

1.410 
37.655 
54.439 
0.636 
5.860 

1.310 
37.100 
55.004 
0.636 
5.950 

1.560 
39.185 
54.352 
0.643 
4.260 

1.780 
35.360 
59.290 
0.680 
2.880 

1.280 
38.105 
54.383 
0.792 
5.440 

1.490 
37.153 
58.193 
0.658 
2.506 

Total  .... 

100.000 

100.000 

100.000 

100.000 

100.000 

100.000 

Coke,  per  cent.  . 
Fuel  ratio  .  .  . 

60.935 
1:1.47 
McCreath. 

61.590 
1:1.48 
McCreath. 

59.255 
1  :  1.38 
McCreath. 

62.860 
1  :  1.67 
McCreath. 

60.615 
1:1.42 
McCreath. 

61.357 
1:1.56 
McCreath. 

DESTRUCTIVE  DISTILLATION  OF  COAL. 
//.    Coking  Coals. 


399 


Connells- 
ville,    . 
Frick  &  Co. 

Bennington, 
Cambria 
Iron 
Company. 

Broad  Top, 
Baniet. 

Broad  Top, 
Kelley. 

Cumber- 
land. 

Huntingdon 
County, 
Alloway 
Colliery. 

Moisture  .... 
Volatile  matter  . 
Fixed  carbon    . 
Sulphur  .... 
Ash    

1.260 
30.107 
59.616 
0.784 
8.233 

1.400 
27.225 
61.843 
2.602 
6.930 

16.00 
74.65 
1.85 
7.50 

19.68 
71.12 
1.70 
750 

1.10 
15.30 
73.28 
1.23 
908 

0.250 
14.510 
77.042 
1.338 
6860 

Total.  .  .  . 

100.000 

100.000 

100.00 

100.00 

100.00 

100.000 

Coke,  per  cent.  . 
Fuel  ratio  .  .  . 

68.63 
1:1.98 
McCreath. 

71.375 
1:2.27 
McCreath. 

81.00 
T.T.Morrell. 

71.00 
T.T.Morrell. 

83.59 
1  :  4.78 
McCreath. 

85.24 
1  :  5.30 
McCreath. 

HI.   Non-coking  Coals  (Block  Coal). 


Mercer 
County,  Pa., 
Sharon  Coal. 

Youngstown, 
Ohio. 

Mercer 
County,  Pa. 

Straitsville, 
Ohio. 

Brazil,  Ind. 

Moisture     .... 
Volatile  matter  .    . 
Fixed  carbon     .    . 
Sulphur  ..... 

3.79 
35.30 
63.875 
0675 

3.60 
32.58 
62.66 
(0  85^ 

3.80 
25.49 
68.03 
1  04 

36'.  50 
55.60 
0.96 

40J5 
57.20 
0.75 

Ash     

6.36 

\\J.O-J) 

1  16 

1.70 

6.94 

1.90 

Total  .... 

100.000 

100.00 

100.06 

100.00 

100.00 

Coke,  per  cent.  .    . 

60.91 
McCreath. 

Wormley. 

Jno.  Fulton. 

61.00 
Wormley. 

58.00 
Prof.  Cox. 

Effects  of  High  or  Low  Temperature  in  the  Distillation  of  Coal.— 
Coal  when  distilled  at  a  low  temperature  yields  products  of  a  very  dif- 
ferent nature  from  those  obtained  if  the  temperature  employed  had  been 
high.  On  this  subject  Professor  Edmund  T.  Mills,  of  Glasgow,  in  his 
little  manual  on  "Destructive  Distillation"  (3d  ed.,  p.  9),  states  that 
"at  a  very  high  temperature  the  products  from  coal  and  shales  are 
carbon  and  carbonized  gases  of  low  illuminating  power,  with  but  little 
liquid  distillate ;  at  a  low  temperature  there  is  much  liquid  product  and 
gas  of  high  illuminating  power.  The  greatest  amount  of  liquid  product 
of  low  boiling-point  is  found  in  American  and  Russian  petroleums,  which 
have  probably  been  produced  by  the  long-continued  application  of  a 
very  gentle  natural  heat. 

"When  coal  is  slowly  heated  (as  must  be  to  a  great  extent  the  case 
when  it  is  broken  fine,  or  when  a  large  retort  is  used),  its  oxygen  is 
chiefly  converted  into  water;  when  rapidly  heated,  the  oxygen  is  ex- 
pelled as  carbonic  oxides." 

To  show  the  verification  of  these  principles  in  practice,  the  results  of 
high  and  low  temperature  distillation  upon  three  different  coals  may  be 
quoted  from  the  same  authority : 


400  INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 
Yield  of  Gas,  Oil,  etc.,  from  Shales  and  Coals  at  High  and  Low  Heats. 


GOOD  SHALES. 

BOGHEAD  COAL. 

GAS  COAL. 

High  heats. 

Low  heats. 

High  heats. 

Low  heats. 

High  heats. 

Low  heats. 

£* 

32 

if 

>a 

Coke 

Coke 
or  c 
Speci 
coal 

f  Gas              .  .      .  . 

13.65 
3.65 
11.04 
0.99 
2.82 

2.54 
6.47 
17.65 

37.32 
2.43 
20.65 
0.18 
0.80 

4.83 
3.23 
50.29 

20.49 
3.09 
17.08 
0.29 
4.15 

6.49 

7.24 
26.45 

Ammonia-water  .  . 
Tar  or  oil    

Sulphur    

.  Water  at  212°  .... 

t  Fixed  carbon  .  .  . 
•\  Sulphur  ...... 

32.15 
4.16 
1.05 
62.64 

26.66 
10.81 

62?53 

61.38 
9.01 
0.06 
29.55 

58.35 
12.40 

29.25 

45.10 

45.00 
0.34 
9.56 

40.18 
49.93 

'9.89* 

I  Ash  

(dry)  per  ton  of  shale 
oal  

67.85 

73.34 

38.62 

41.65 

54.90 

59.82 

100.00 

100.00 

100.00 

100.00 

100.00 

100.00 

1,520  Ibs. 
l.i 

1,642.2  Ibs. 
18 

865  Ibs. 
U 

934  Ibs. 
.24 

1,230  Ibs. 
1.5 

1,340  Ibs. 
96 

ic  gravity  of  shale  or 

NOTE.— The  low  heat  results  were  gotten  by  distilling  the  sample  in  a  two-inch  iron  tube  in  a  gas- 
furnace. 

Lunge  (Coal-Tar  and  Ammonia,  2d  ed.,  p.  17)  states  that  "The 
quantity,  and  to  a  much  greater  extent  the  quality,  of  the  tar  are  influ- 
enced by  the  temperature  at  which  the  decomposition  of  the  case  is 
carried  on.  Low  temperatures,  with  nine  thousand  cubic  feet  of  gas  per 
ton  of  coal,  will  yield,  with  some  coals,  sixteen  gallons  of  tar;  whilst  at 
high  temperatures  the  yield  will  be  but  nine  gallons,  with  about  eleven 
thousand  cubic  feet  of  gas,  from  the  same  coal."*  If  the  temperature 
be  a  comparatively  low  one,  mostly  such  hydrocarbons  are  formed  as 
belong  to  a  paraffin  (methane)  series,  having  the  general  formula 
CnH.,n  +  2,  along  with  the  olefins,  CnH2n.  The  lower  members  of  this 
series  are  liquid,  and,  furnished  in  the  pure  state,  are  lighting  and 
lubricating  oils ;  the  higher  ones  are  solid  and  form  commercial  paraffin. 
They  are  always  accompanied  by  oxygenized  derivatives  of  the  benzene 
series  (phenols) ;  but  of  these  the  more  complicated  ones  predominate,  in 
some  of  which  methyl  occurs  in  the  benzene  nucleus,  in  others  replacing 
the  hydrogen  of  hydroxyl, — e.g.,  cresol,  CGH4(CH3)  (OH)  ;  guaiacol, 
C6H4(OH)(OCH3);  creosol,  C«H,(CH8)(OH)(OCHt),  etc-  Liquid 
products  prevail;  and  among  the  watery  ones  acetic  acid  (which  is  again 
a  compound  of  the  fatty  series)  is  paramount.  Of  course  also  permanent 
gases  are  always  given  off,  though  in  comparatively  small  quantity. 

If,  on  the  other  hand,  the  coal  has  been  decomposed  at  a  very  high 
temperature,  the  molecules  are  grouped  quite  differently.  Whilst  the 
olefins  and  members  of  the  acetylene  series-,  still  occur  more  or  less,  the 
hydrocarbons  of  the  paraffin  series  disappear  almost  entirely;  and  from 
them  are  formed  on  the  one  hand  compounds  much  richer  in  carbon,  on 
the  other  hand  more  hydrogenized  bodies.  The  latter  always  occur  in 
the  gaseous  state ;  hence  the  gas  so  produced  contains  methane,  or  marsh- 


*  Davis,  Journ.  Soc.  Chem.  Ind.,  1886,  p.  5. 


Showing  the  most  important  of  the  products  derived  from 

manufad 


The  direct  products  which  can  be  separated  as  they  come  over  from  the  still,  by  filtra- 
tion or  other  simple  processes,  are  marked  thus,  |  Those  substances  which  are 
prepared  by  further  chemical  treatment  are  marked 


COAL  GAS'. 

GAS-UQOOR. 

c< 


Liquid 
Ammonia 

Sulphate 
of 
Ammonia. 

Chloride 
Of 
Ammonia. 

Carbon- 
ate of 
Ammonia. 

Oils  lighter  than  water  or 
Crude  Naphtha. 


Oils  heavier  than  v 
or  tar,  commc 


BENZOL. 


TOLUOL. 


Nitrb- 
Benzol. 


Mtro- 
ToluoL 


TbLUl- 
DINE. 


XYLOL. 


CUMOL. 


Nitro- 
Xylol. 


PYRIDINE. 


CARBOLIC 
ACID. 


CRESYLIC 
ACID. 


CARBOLIC 
ACID. 


CRESYLIC 
ACID. 


Picric 
Acid. 

Aurinc. 

Nitro- 
Cumol. 


For  the  manufacture  of  pure  carbolic, 
cresylic,  and  other  tar  acids,  further  and 
elaborate  treatment  is  required. 


XYLIDINE. 


CUMIDINE. 


RAM 

twcastle  Coal  when  carbonized  by  the  usual  method  for  the 
of  coke. 


The  direct  products  of  the  dead  oils  are  arranged  as  nearly  as  possible  according  to 
'their  respective  volatilities/  and  to  the  order  in  which  they  come  over  from  the  still 


otherwise  dead  oil 
ailed  Creosote. 


PITCH, 


in  WILS,  aistiiiing  irom  oso"  to  750°  F   ^ 

r 
| 

n 

NAPHTHX 

LENE. 

Quinoline 
Series,— 
6.17..  Cryp- 
tidine. 

Phenan- 
threne. 

Carbazol. 

ACENERA"      Acri^ne.       Pyrene       Cbrysene.      **£™£ 

Nitro- 
Naphtha- 
lene 

Phenan- 
threne 
Quinone. 

Anthra-                            Pyrene         Chryso- 
quinone                            Qyinone.       Quinone. 

Naphthyl- 
amine. 

Diphenic 
Acid. 

Anthra- 
qninone 
Sulphonic 
Acid 

NAPH- 

THOU 

HHTHALTC 
ACID. 

ALIZA 
RINE. 

PORPU- 

RINE. 

;  -  •  •< 


DESTRUCTIVE  DISTILLATION  OF  COAL.  401 

gas,  CH4,  and  free  hydrogen  as  principal  constituents,  and  is  very 
much  increased  in  quantity.  The  carbon  thus  set  free  is  partly  deposited 
in  the  retorts  themselves,  and  then  occurs  in  a  very  compact  graphitoidal 
form ;  another  portion  of  the  free  carbon  occurs  in  a  state  of  extremely 
fine  division  in  the  tar,  and  forms  a  constituent  of  the  pitch  or  coke 
remaining  behind  from  tar-distilling;  another  portion  contributes  to  the 
formation  of  compounds  richer  in  carbon,  belonging  to  the  "aromatic" 
series,  all  of  which  are  derived  from  benzene,  C6H6.  At  the  same  time 
the  action  of  heat  effects  further  molecular  "condensations,"  usually 
with  separation  of  hydrogen,  by  which  process  compounds  of  a  higher 
molecular  weight  are  formed,  as  naphthalene,  anthracene,  phenanthrene, 
chrysene,  etc.  The  never  absent  oxygen  must  also  in  this  case  cause  the 
formation  of  phenols;  but  here  phenol  proper,  or  carbolic  acid  C0H5(OH), 
predominates,  whilst  cresol  and  the  other  homologues  are  diminished  in 
quantity,  and  the  dioxy-benzenes,  as  well  as  their  methylated  derivatives, 
disappear  altogether.  The  above  will  be  better  illustrated  by  the  state- 
ment (from  Stohmann-Kerl's  "Chemie,"  3d  ed.,  vi.  p.  1162)  that 
Zwickau  glance  coal  yielded  the  following  quite  different  products,  ac- 
cording to  whether  it  was  put  into  a  cold  retort  and  gradually  brought 
to  a  red  heat  (a),  or  distilled  quickly  from  a  very  hot  retort  (&)  : 

a.  b. 

Coke    60.0  50.0 

Water    10.7  7.7 

Tar    12.0  10.0 

Gas  and   loss    17.1  32.1 

The  tar  from  (a)  consisted  of  photogen,  paraffin  oil,  lubricating  oil, 
paraffin,  and  creosote;  that  from  (&),  of  benzene,  toluene,  naphthalene, 
anthracene  (together  with  heavy  oils  corresponding  to  the  paraffin  and 
lubricating  oil),  and  much  creosote. 

The  annexed  diagram,  constructed  by  S.  B.  Boulton,  and  published 
in  the  Society  of  Chem.  Ind.  Journal,  1885,  p.  471,  represents  the  whole 
process  of  the  destructive  distillation  of  coal,  including  the  subsequent 
treatment  of  the  main  fractions,  and  exhibits  in  their  proper  order  the 
various  products  obtained  therefrom. 

n.  Processes  of  Treatment. 

1.  GAS-RETORT  DISTILLATION  OF  COAL. — The  distillation  of  coal  as 
carried  out  in  retorts  differs  from  distillations  of  other  substances  mainly 
in  the  apparatus  employed  and  in  the  nature  of  the  substances  to  be 
recovered.  For  gas  purposes,  retorts,  wherein  the  decomposition  of  the 
coal  used  takes  place,  are  made  use  of,  which  were  originally  constructed 
of  cast  iron,  about  one  inch  in  thickness,  twelve  to  fifteen  inches  in 
width,  and  about  seven  feet  in  length,  closed  at  the  rear  end,  and  pro- 
vided at  the  front  or  mouth  with  a  heavy  shoulder  or  rim  supplied  with 
studs  to  which  is  attached  a  cast-iron  extension,  technically  termed  the 
"neck,"  which  carries  on  its  upper  side  a  flange  to  which  are  secured 
upright  pipes  serving  to  lead  the  gases  generated  away  from  the  retort. 

26 


402   INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

The  front  of  the  neck  is  provided  with  a  screw  clamp  to  retain  the  lid 
or  cap  of  the  retort  in  position.  Iron  retorts  are  destroyed  with  great 
rapidity;  the  destruction  being  caused  by  the  heat  of  combustion  of  the 
fuel  used,  the  sulphur  in  the  gas  coal  (an  impurity  always  present  in 
more  or  less  quantity),  which  acts,  forming  sulphide  of  iron,  and  the 
carbon,  which,  as  a  carbide  of  iron,  graphitic  in  appearance,  forms  layers 
within  the  retort  from  one  to  two  inches  in  thickness.  The  oxygen  of 
the  air  also  has  a  very  deleterious  influence,  especially  upon  retorts  when 
heated  to  redness. 

In  later  years  fire-clay  retorts  have  been  substituted  for  those  made  of 
cast  iron,  for  the  reason  that  they  are  more  durable.  These  retorts  are 
made  of  a  mixture  of  clay  and  sand,  and  are  furnished  to  the  gas-works 
in  several  shapes,  the  semi-cylindrical  being  the  one  most  generally 
employed.  The  sizes  vary,  six  to  nine  feet  in  length,  fifteen  to  twenty 
inches  in  width,  and  from  ten  to  fifteen  inches  in  height  being  the  aver- 
age, and  take  a  charge  of  one  hundred  and  fifty  to  two  hundred  pounds 
of  coal.  Retorts  have  been  made  up  to  nineteen  feet  in  length,  being 
charged  from  both  ends. 

The  retorts,  varying  in  number  from  five  to  seven,  or  even  nine  and 
more,  are  mounted  in  brick  furnaces  of  special  construction,  in  such  a 
manner  that  the  gases  of  combustion  of  the  coal  will  pass  around  and 
over  the  retorts  and  out  through  a  main  flue  leading  to  the  chimney. 
The  fuel  employed  can  be  either  coal,  coke,  or  a  mixture  of  both.  Gas 
as  a  means  of  firing  has  been  used  for  the  purpose,  the  method  being 
based  upon  the  well-known  regenerative  system  of  Sir  William  Siemens. 

The  retorts  are  charged  by  hand,  care  being  taken  to  evenly  dis- 
tribute the  coal  over  the  sole,  or  bottom,  and  to  close  it  quickly.  Various 
attempts  have  been  made  to  perform  this  laborious  work  with  mechanical 
means,  but  at  present  no  entirely  satisfactory  substitute  has  been  found. 

The  products  of  distillation  pass  from  the  retorts  proper  through  the 
neck,  and  upward  through  cast-iron  stand-pipes,  which  are  provided 
with  goose-neck  outlets,  dipping  below  the  surface  of  water  in  what  is 
termed  the  hydraulic  main. 

It  is  in  this  part  of  the  process  that  the  main  bulk  of  the  tar  is 
obtained,  together  with  the  ammonia-liquor.  V  The  hydraulic  main  is 
provided  with  an  overflow-pipe  through  which  all  the  tarry  matters  pass, 
This  overflow-pipe  leads  to  the  tar-well,  wherein  the  liquid  products 
collect. 

The  gas  having  been  freed  from  the  tarry  matters,  etc.,  contained, 
passes  from  the  hydraulic  main  with  a  considerably  elevated  tempera- 
ture, carrying  in  a  vaporized  state  hydrocarbons  that  would  separate 
as  its  temperature  is  lowered.  It  is  necessarily  very  important  to  remove 
these  volatile  and  condensable  products,  which  is  effected  by  causing  the 
gas  to  pass  through  a  series  of  pipes,  which  reduces  its  temperature 
very  close  to  that  of  the  atmosphere.  The  older  form  of  condenser  was 
a  series  of  pipes  completely  covered  with  water,  similar  to  the  worms  as 
at  present  employed  in  connection  with  spirit  and  other  distillations. 
This  arrangement  was  replaced,  however,  by  the  forms  now  universally 


DESTRUCTIVE  DISTILLATION  OF  COAL. 


403 


FIG.  99. 


employed,  and  known  as  the  atmospheric  condensers,  consisting  of  ver- 
tical pipes  connected  in  pairs  near  the  top  by  straight  or  curved  pieces; 
the  lower  end  of  the  upright  pipes  being  connected  to  a  box  or  trough 
containing  water,  divided  by  partitions,  causing  the  gas  to  pass  up  and 
down  alternately,  as  shown  in  Figs.  99  and  100. 
Tarry  matters  and  more  ammoniacal  liquor  are 
again  obtained,  wrhich  find  their  way  to  the  tar- well. 
The   gas   after   circulating   through   the  con- 
densers still   contains  impurities,   which  are  re- 
moved by  passing  it  through  an  apparatus  known 
as  the  scrubber,   consisting  essentially  of  cylin- 
drical wrought-iron  towers  filled  with  coke,  over 
and  through  which  trickles  a  light  flow  of  water, 
or  better,  weak  ammoniacal  liquor;  the  gas  pass- 
ing upward  meets  this  downward  flow  of  liquid, 
and  to  it  gives  up  the  hydrogen  sulphide  con- 
tained, with  the  formation  of  ammonium  sulphide, 
etc.     Tarry  matters  again  are  separated,  and  in 
time  cause  the  coke  to  become  somewhat  clogged. 
This  apparent  drawback  has  led  to  the  introduc- 
tion  of  perforated  iron  plates  in  place  of  the 
coke,  or,  what  has  also  proved  equally  efficient, 
wooden    lattice    screens.      Anderson's    rotating 
scrubber  consists  of  brushes,  which  while  rotating 
dip  in  a  trough  of  ammoniacal  liquor,  and  thereby 
perform   functions   similar   to  the   means   above 
mentioned.    Another  form  of  scrubber  consists  of 
a  tower  containing  cast-iron  plates  provided  with 
perforations,   through   which   ammoniacal   liquor 
passes  in  its  downward  course,  meeting  the  gas. 
The  liquid  is  continuously  pumped  to  the  top, 
when  it  again  passes  down,  coming  in  contact  with 
fresh  gas.     This  is  repeated  until  the  liquor  has 
taken  up  sufficient  ammonia  to  make  it  available  to  the  ammonia  sul- 
phate manufacturer.     From  the   scrubber  the   gas   passes   on   to  the 
purifiers,  where  the  hydrogen  sulphide  still  remaining,  carbon-disulphide 

FIG.  100. 


vapor,  and  the  carbonic  acid  are  removed.  The  purifiers  ordinarily 
used  consist  of  a  large  shallow  box,  constructed  of  cast  iron  in  sections, 
and  bolted  together,  or  of  wrought-iron  plates,  provided  with  a  cover, 
the  edge  of  which  dips  in  water  contained  in  a  channel  provided  at  the 


404  INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

top  of  the  box,  acting  as  a  seal  and  preventing  the  escape  of  gas  at  that 
point,  as  shown  in  Fig.  101.  The  purifying  agent  first  employed  was 
slaked  lime,  which  was  spread  upon  wood  screens,  within  the  box,  from 
four  to  six  in  number,  one  above  the  other,  and  supported  by  ledges. 
Hydrogen  sulphide  and  carbon  dioxide  are  absorbed  by  the  lime,  while 
compounds  of  cyanogen  are  at  the  same  time  decomposed. 

Four  purifiers  are  generally  used,  three  being  in  service,  while  the 
fourth  is  reserved  charged  with  fresh  lime.  Gas  enters  the  one  contain- 
ing the  oldest  lime,  and  when  it  is  noticed  that  lead-acetate  paper  is  dis- 
colored by  some  of  the  gas  acting  upon  it,  it  is  known  that  the  purifying 
material  is  saturated;  this  purifier  is  discontinued,  and  the  freshly- 
charged  one  placed  in  service.  In  this  manner  they  are  continually 
rotated. 

Ferric  hydroxide  (hydrated  ferric  oxide)  is  now  largely  employed  in 
gas  purification, — Laming  process.  Gas  charged  with  hydrogen  sulphide 
coming  in  contact  with  the  above  causes  a  reduction  to  ferrous  sulphide, 

FIG.  101. 


at  the  same  time  some  sulphur  is  deposited,  with  the  formation  of  water. 
This  process  does  not  absorb  the  carbon  dioxide  from  the  gas ;  for  this  pur- 
pose lime  is  mixed  with  the  ferric  hydroxide,  together  with  some  cinders 
or  sawdust,  in  order  that  the  whole  may  be  porous,  and  resist  as  little 
as  possible  the  passage  of  the  gas.  When  the  purifying  action  has  ceased, 
simply  exposing  the  inert  mixture  to  the  action  of  the  air  for  a  while 
restores  its  properties,  until  after  repeated  use  it  becomes  so  charged  with 
separated  sulphur  that  it  is  no  longer  available. 

The  introduction  of  free  oxygen  into  the  gas,  previous  to  it  entering 
the  purifiers,  has  been  found  to  lengthen  the  time  during  which  the  oxide 
of  iron  can  remain  without  being  changed,  thereby  saving  much  handling. 
It  has  also  improved  the  illuminating  power  of  the  gas.  (Journ.  Soc. 
Chem.  Ind.,  vol.  viii,  pp.  84  and  694.) 

From  the  purifiers  the  gas  passes  through  the  meter  of  the  works, 
where  the  volume  is  registered,  then  on  to  the  gas-holders,  where  it  is 
stored  and  from  which  it  is  distributed. 


DESTRUCTIVE  DISTILLATION  OF  COAL. 


405 


The  following  table  illustrates  the  composition  of  illuminating  gas 
taken  from  various  stages  of  manufacture : 


Entering 
the  air-con- 
denser. 

Entering 
the 
scrubber. 

Entering 
the 
Laming's 
purifier. 

Entering 
the  lime- 
purifier. 

Entering 
the  gas- 
holder. 

Hydrogen   

37.97 

37.97 

37.97 

37.97 

37.97 

Marsh-gas  

39.78 

38.81 

38.48 

40.29 

39.37 

Carbonic  oxide  

7.21 

7.15 

7.11 

3.93 

3.97 

Heavy  hydrocarbons     

4  19 

4.66 

446 

4.66 

4.29 

Nitrogen     

4.81 

4  99 

6.89 

7.86 

9.99 

0.31 

047 

0.15 

0.48 

0.61 

Carbon  dioxide  

3.72 

3.87 

3.39 

3.33 

0.41 

Hydrogen  sulphide   

1.06 

1.47 

0.56 

0.36 

Ammonia    

0.95 

0.54 

2.  COKE-OVEN  DISTILLATION  OF  COAL. — The  burning  of  coke  in  pits, 
"meilers,"  or  mounds,  represents  the  first  rough  and  wasteful  method 
of  converting  bituminous  coal  into  coke;  involving,  at  the  same  time, 
the  total  loss  of  all  the  volatile  matter  of  the  coal.  It  allows,  however, 
of  the  smothering  the  finished  coke  with  fine  dust,  instead  of  requiring  it 
to  be  quenched  with  water,  as  in  other  methods.  The  so-called  "bee- 
hive" ovens  allow  of  the  volatilizing  of  a  much  greater  amount  of 
sulphur  in  the  coal,  and  give  a  decidedly  increased  yield  of  coke  over 
the  pit-burning  method.  The  charge  can  be  run  through,  too,  in  less 
than  half  the  time.  Some  air  is  admitted  in  both  cases,  with  consequent 
loss  of  coke,  and  no  attempt  is  made  to  save  the  residuals  in  either  case. 

The  distillation  of  coal  in  ovens  differs  materially  from  the  older 
methods  of  production  in  piles  or  kilns  in  that  the  inflammable  gases 
given  off  are  to  some  extent  utilized. 

Among  the  earlier  forms  of  ovens  planned  for  the  collection  of  resid- 
uals (gas,  tar,  and  ammonia)  were  the  Appolt,  which  was  a  vertical 
oven  surrounded  by  air  spaces  in  which  combustion  took  place,  and  the 
Coppee,  which  was  a  horizontal  oven  with  vertical  side  canals  for  the 
combustion  of  gas  and  air.  One  of  the  most  successful  forms  based  upon 
the  Coppee  principle  but  using  the  Siemens  regenerative  firing  is  the 
Otto-Hoffmann  oven,  which  has  been  extensively  adopted  in  this  country. 

The  Simon-Carves  oven,  illustrated  in  Fig.  102,  on  the  other  hand, 
has  horizontal  heating  chambers  for  gas  combustion.  Mr.  Henry  Simon, 
C.E.,  in  an  address  before  the  British  Iron  and  Steel  Institute  (Journ. 
Iron  and  Steel  Inst.,  No.  1,  1880),  states:  "According  to  our  system, 
the  coal  is  rapidly  carbonized  by  subjecting  a  comparatively  thin  layer 
of  it  to  a  high  temperature  in  a  closed  retort-like  vessel,  and,  whilst  in 
the  bee-hive  ovens  the  volatile  products  are  burned  inside,  we  burn  them 
around  and  outside  of  this  retort-like  vessel,  and  only  after  they  are 
deprived  of  the  tar  and  ammoniacal  liquor.  Each  oven  is  in  the  form 
of  a  long,  high,  narrow  chamber  of  brick-work,  and  a  number  of  these 
are  built  side  by  side,  with  partition-walls  between  them  sufficiently 
thick  to  contain  horizontal  flues.  Flues  are  also  formed  under  the  floor 


406   INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

FIG.  102. 


DESTRUCTIVE  DISTILLATION  OF  COAL.  407 

of  each  oven,  and  at  one  end  of  these  is  a  small  fireplace,  consisting  of  a 
fire-grate  and  ash-pit,  with  suitable  door,  the  fire-door  having  fitted 
above  it  a  nozzle,  through  which  gas  produced  from  the  coking  is  ad- 
mitted to  form  a  flame  over  some  fuel  burning  on  the  grate.  Only  a 
very  trifling  amount  of  such  fuel,  consisting  exclusively  of  the  small 
refuse  coke,  is  used  here,  its  function  being  really  more  that  of  igniting 
the  gas  than  that  of  giving  off  heat.  These  grates  are  not  charged  with  fuel 
more  than  twice  in  each  twenty-four  hours  when  in  regular  work.  The 
products  of  combustion  pass  from  the  fireplace  along  a  flue  under  the 
oven  floor  to  the  end  farthest  from  the  fire.  They  return  along  another 
flue  under  the  floor  to  the  fire  end;  they  then  ascend  by  a  flue  in  the 
partition-wall  to  the  uppermost  of  several  horizontal  flues  formed  there- 
in, and  descend  in  a  zig-zag  direction  along  these  flues,  finally 
passing  into  a  horizontal  channel  leading  to  a  chimney.  The  oven  in 
consequence  is  evenly  heated  at  the  bottom  and  sides,  and  the  coal  con- 
tained is  rapidly  and  completely  coked.  No  air  enters  the  chambers,  the 
only  openings  being  for  the  escape  of  the  volatile  products.  The  im- 
proved ovens  are  fed  with  coal  by  openings  in  the  roof,  over  which  coal- 
trucks  are  run  on  rails ;  and  the  coal  is  evenly  distributed  by  rakes  intro- 
duced at  end  openings,  provided  with  doors  faced  with  refractory  mate- 
rial, which  doors  are  closed  and  kept  tightly  luted  while  the  oven  is  in 
operation.  The  feed-holes  in  the  roof  are  also  provided  with  covers. 
Through  the  middle  of  the  roof  rises  a  gas-pipe  provided  with  a  hy- 
draulic valve,  which  closes  the  passage  by  a  lip  projecting  down  from  it 
into  an  annular  cavity  surrounding  its  seating,  in  which  it  is  immersed 
in  a  quantity  of  tar  and  ammoniacal  liquor,  lodged  there  during  previous 
distillations.  The  volatile  products  of  the  coal  distillation  rise  by  the 
gas-pipe,  and  are  led  through  a  range  of  pipes  kept  cool  by  external 
wetting,  so  that  the  tar  and  ammoniacal  liquor  become  condensed  and 
separated  from  the  combustible  gas. ' '  When  the  charge  of  coal  has  been 
converted  to  coke,  it  is  removed  from  the  ovens  by  means  of  a  piston 
worked  by  an  engine  traversing  rails  in  front  of  the  battery.  The  yield 
of  coke  has  been  stated  to  be  from  seventy-five  to  seventy-seven  per  cent, 
of  the  coal.  During  a  run  of  two  hundred  and  fifteen  days,  the  yield 
of  residuals  averaged  27.70  gallons  of  ammoniacal  liquors  per  ton  of 
coal  carbonized,  and  6.12  gallons  of  tar  per  ton  of  coal  carbonized. 

An  improved  form  of  oven  analogous  to  the  Simon-Carves  but  with 
improved  utilization  of  heat  and  greater  yield  of  residuals  is  the  Semet- 
Solvay,  which  has  practically  divided  the  field  in  this  country  with  the 
Otto-Hoffmann  oven.  While  the  regenerative  heating  is  not  used  in  the 
Semet-Solvay  oven,  the  air  for  combustion  and  sometimes  the  gas  is 
heated  by  the  waste  gases  of  combustion.  It  is  claimed  that  by  the 
horizontal  flue  for  the  burning  of  the  fuel  gas  a  more  uniform  and  higher 
temperature  is  obtained. 

Considerable  difference  exists  between  the  tars  obtained  from  the 
different  coking  processes  above  referred  to.  The  Simon-Carves  tar 
has  a  specific  gravity  of  1.106,  and  closely  resembles,  chemically,  the  tars 
produced  in  the  illuminating  (retort)  gas  process,  both  being  obtained 


408   INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

at  a  high  temperature.  The  Simon-Carves  tar  is  rich  in  naphthalene 
and  anthracene,  but  low  in  naphtha,  benzene,  phenols,  etc.  Analogous 
to  this,  as  might  be  expected,  is  the  Semet-Solvay  tar.  A  sample  from 
Glassport,  Pa.,  gave  3.7  per  cent,  light  oils,  9.8  per  cent,  middle  oils, 
12  per  cent,  heavy  oils  and  4.3  per  cent,  anthracene  oil,  and  had  a 
specific  gravity  1.170.  On  the  other  hand,  a  sample  of  Otto  oven  oil 
(Lunge,  Die  Industrie  des  Steinkohlentheers  und  Ammoniaks,  4te  Auf., 
p.  87)  gave  light  oil  3.4,  creosote  oil  14.5  per  cent.,  crude  naphthalene 
6.7  per  cent.,  and  27.3  per  cent,  anthracene  oil.  Much  of  the  gas  pro- 
duced in  the  by-product  coke  oven  contains  benzol  vapor  and  this  is 
washed  out  of  it,  so  that  much  more  is  obtained  than  the  percentage  of 
light  oils  in  the  tar  would  indicate. 

The  following  comparison  of  Otto-Hoffmann  coke  oven  tar  with  gas 
retort  tar  from  Dammer's  Chemische  Technologic  der  Neuzeit,  vol.  ii, 
p.  98,  1910)  is  instructive : 


Distillation 
temperature. 

Tar  from  Otto-Hoffmann 
oven. 

Gas-tar. 

|rf 

"gcd 
5>5 

.£  a 
02 

O03 

Q 

L 

s§ 

>, 
§ 

i 
o 

>, 

i 

o 

1 

CO 

s 

D 

Light  oil  

80°-170°C. 
170°-230° 
230°-270° 
Above  270° 

1.26 
14.76 
7.07 
21.38 
53.03 
1.52 
1.01 

1.38 
11.46 
8.56 
20.63 
53.68 
1.93 
2.36 

6.55 
10.54 
7.62 
44.35 
30.55 
trace 
0.39 

3.0 
7.5 
33.5 
10.5 
45.5 

2.5 
2.5 
25.0 
10.0 
60.0 

1.65 

10.66 
8.18 
14.05 
61.16 
1.81 
2.49 

Middle  oil  
Heavy  oil  

Anthracene  oil    .   . 
Pitch  

Water   

Loss  ,   

Specific  gravity 

100.00 
1.188 

100.00 
1.140 

100.00 
1.155 

100.00 
1.155 

100.00 
1.155 

100.00 

3.  FRACTIONAL  SEPARATION  OF  CRUDE  COAL-TAR. — Following  gas 
retort  distillation,  in  point  of  technical  importance  is  certainly  the  dis- 
tillation of  the  coal-tar  obtained  from  the  former  processes  and  the  separa- 
tion therefrom  of  certain  constituents  which  have  a  wide  application  in 
several  industries.  The  same  general  mechanical  arrangement,  though 
somewhat  simplified,  is  employed,  consisting  of  a  still,  a  condenser,  and 
a  receiver.  The  still  should  be  constructed  entirely  of  wrought  iron, 
and  can  be  either  horizontal  or  vertical.  Horizontal  stills  are,  accord- 
ing to  Lunge,  far  less  economical  than  the  vertical.  Fig.  103  is  a  ver- 
tical section  of  a  tar-still  showing  the  construction  and  fittings.  The 
heat  from  the  fire  on  the  grate  &  is  prevented  from  impinging  against 
the  concave  bottom  of  the  still  by  means  of  the  arch  g,  but  passes  through 
the  openings  h  in  the  circular  wall  k  into  vertical  flues  i,  from  which 
it  enters  the  annular  space  I  and  through  flues  in  the  front  of  the  still 
to  the  upper  space  n,  finally  entering  the  flue  p,  which  leads  to  the 


DESTRUCTIVE  DISTILLATION  OF  COAL. 


409 


chimney.  The  supply  pipe  r  is  for  feeding  the  still,  the  pipe  s  is  an 
overflow,  and  serves  to  indicate  when  the  tank  is  full.  The  cock  a  is 
for  drawing  off  the  pitch.  The  still-head  t  is  for  conducting  the  vapors, 
and  is  connected  with  the  condenser.  The  system  of  pipes  x  y  z  indi- 
cated is  for  conducting  superheated  steam  into  the  still  for  finishing  the 
distillation;  the  pipes  conforming  to  the  shape  of  the  bottom,  are  pro- 

FIG.  103. 


vided  with  a  number  of  jets  for  a  more  equal  distribution  of  the  steam. 
The  remaining  attachments  require  no  further  mention. 

The  condenser  consists  of  a  coil  of  pipe  immersed  in  water  contained 
in  an  iron  tank.  In  England,  the  pipe  used  is  from  six  to  nine  feet  in 
length,  and  from  four  to  six  inches  in  diameter ;  the  total  length  for  one 
still  is  calculated  at  from  one  hundred  and  forty  to  two  hundred  feet. 
In  Germany,  preference  is  given  to  worms  of  iron  (or  lead,  in  which  case 


410  INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

the  pipe  from  the  still  must  be  continued  below  the  surface  of  the  water 
in  the  condenser  and  join  the  worm  there,  in  order  to  obviate  the  possi- 
bility of  it  being  melted),  made  of  two-inch  pipe,  and  mounted  in  cir- 
cular tanks  provided  with  a  steam-pipe  for  heating  the  water,  and  also 
with  a  small  pipe  connected  with  the  worm  for  blowing  in  steam  when- 
ever it  is  necessary  to  clean  it. 

Connected  with  the  condenser,  and  located  at  a  safe  distance  from  the 
still,  is  the  receiver,  which  can  be  of  any  convenient  shape,  and  of  such 
a  size  as  to  contain  the  whole  of  one  fraction;  or  a  number  can  be  em- 
ployed, each  acting  as  a  store-tank  and  receiver.  For  the  receivers  to 
contain  the  volatile  fractions,  tight-closing  covers  must  be  supplied  to 
guard  against  evaporation  and  fire,"  and  the  one  containing  the  first 
fraction  must  have  means  for  separating  the  oily  from  the  watery  layer. 
The  receivers  for  the  oils  which  deposit  crystalline  matter  must  be  so 
arranged  that  they  can  be  easily  cleaned. 

Coal-tar  (Allen,  Commercial  Organic  Analysis,  3d  ed.,  vol.  ii,  Part 
ii,  p.  47),  ''as  obtained  as  a  by-product  in  the  manufacture  of  illuminat- 
ing gas,  is  a  black  viscid  fluid  of  a  characteristic  and  disagreeable  odor. 
The  specific  gravity  ranges  from  1.10  to  1.20,  being  usually  between 
1.12  and  1.15. 

"As  coal-tar  is  always  more  or  less  mixed  with  ammcniacal  liquor, 
the  consituents  of  the  latter  liquid  are  present  in  addition  to  those  of 
the  tar  proper,  and  the  constituents  of  the  illuminating  gas  itself  are  also 
present  in  a  state  of  solution. 

''The  first  treatment  of  coal-tar  on  a  large  scale  consists  in  distilling 
it  in  iron  retorts  and  collecting  the  distillate  in  three  or  four  fractions. 
The  temperatures  at  which  the  receivers  are  charged  vary  considerably 
with  the  practice  of  different  works,  and  hence  the  products  are  far  from 
being  strictly  parallel." 

The  annexed  table  indicates  the  three  most  important  methods  of 
f  ractionation : 


A. 

B. 

C. 

Product. 

Distilling- 
point  °  C. 

Product. 

Distilling- 
point  °  C. 

Product. 

Distilling- 
point°C. 

Crude  naphtha, 
or  light  oils    . 
Heavy  oils,  dead 
oils,    or    creo- 
sote oils  .    .    . 
Anthracene  oils 

0  to  170 

170  to  270 
above  270 

First  runnings, 
or  first  light 
oils     .... 
Second  light  oils 
Carbolic  oils     . 
Creosote  oils 

0  to  110 
110  to  210 
210  to  240 
240  to  270 

Light  naphtha 
Light  oils  .  .  . 
Carbolic  oils  . 
Creosote  oils  . 
Anthracene  oils 
Pitch  .... 

Oto  110 
110  to  170 
170  to  225 
225  to  270 
270  to  360 

Pitch  

.A  nthracene  oils 

above  270 

Pitch     .... 

\ 

The  principal  constituents  of  coal-tar  are  separated,  one  from  the 
other,  by  means  of  fractional  distillation,  a  process  depending  upon  the 
fact  that,  if  a  mixture  of  liquids,  each  having  a  different  boiling-point, 
be  heated,  the  one  having  the  lowest  will  pass  over  first,  and  if  the  tern- 


DESTRUCTIVE  DISTILLATION  OF  COAL.  411 

perature  is  not  increased  beyond  that  point  at  which  the  distillation  of 
this  fraction  takes  place,  no  other  constituent  will  come  over ;  if  the  tem- 
perature be  gradually  increased  the  others  will  follow  in  the  order  of 
their  boiling-points.  In  cases  where  the  boiling-points  are  close,  and 
even  in  others  where  they  are  widely  differing,  the  action  of  one  sub- 
stance upon  another  often  prevents  exact  separations. 

The  hot  stills  (from  the  previous  working)  are  charged  with  fresh 
tar,  all  the  openings  are  then  closed,  and  the  fire  carefully  watched  in 
order  that  no  undue  rise  in  temperature,  and  consequent  boiling  over 
of  the  contents,  may  take  place.  Gases,  ammonia-liquor,  and  light  oils 
distil  over  at  170°,  the  whole  being  designated  "first  runnings."  This 
fraction  is  collected  and  allowed  to  stand,  when  the  watery  portion  sep- 
arates more  or  less  completely  from  the  oils,  which  are  redistilled,  yield- 
ing ammonia  boiling  under  70°,  crude  benzol  at  140°,  which  is  subse- 
quently purified  with  sulphuric  acid  and  distilled,  naphtha,  140°  to  170°, 
treated  as  the  benzol,  yielding  "solvent  naphtha."  This  whole  fraction 
has  a  specific  gravity  nearly  equal  to  that  of  water.  The  second  fraction 
—"middle  oil,"  or  "carbolic  oil"— distils  over  from  170°  to  230°,  and 
contains  the  impure  phenols  or  carbolic  acid  and  naphthalene.  It  is 
crystallized  and  pressed;  the  mother-liquor  is  agitated  with  caustic  soda 
in  an  iron  tank,  the  alkaline  liquor  (carbolate  of  soda)  decomposed  with 
sulphuric  acid,  separating  crude  carbolic  acid,  which  is  distilled  and 
crystallized,  yielding  liquid  and  pure  carbolic  acid  in  crystals.  The 
unchanged  oil  from  the  soda  treatment  is  returned  to  the  second  fraction 
for  re- working.  The  press-cake  from  the  first  treatment  of  this  fraction 
is  purified  with  sulphuric  acid,  distilled,  and  yields  naphthalene.  The 
third  fraction  constitutes  the  heavy  or  dead  oil,  so  called  from  the  fact 
that  the  specific  gravity  is  greater  than  water,  and  boils  from  230°  to 
270°,  occupying  a  position  between  middle  oil  and  the  anthracene  frac- 
tion. It  is  subjected  to  no  further  treatment,  but  is  employed  chiefly 
for  preserving  timber,  varnish  manufacture,  burning  for  lamp-black, 
etc.  The  fourth  fraction,  or  anthracene  oil,  boiling  over  270°,  constitutes 
the  green  oil  or  green  grease,  from  which,  upon  subsequent  treatment, 
the  commercial  anthracene  is  obtained.  This  fraction  is  allowed  to  stand 
for  some  time,  in  order  to  cool  and  to  separate  the  crystallizable  sub- 
stances, when  the  mass  is  drained  from  the  excess  of  oil  and  pressed. 
The  press-cake  is  crude  anthracene,  which  is  dissolved  in  naphtha  and 
known  as  fifty  per  cent,  anthracene.  The  mother-liquor  from  the  first 
pressing  and  the  drainings  are  redistilled,  crystallized  and  pressed, 
yielding  crude  anthracene,  treated  as  above,  and  anthracene  oil.  The 
residue  in  the  still  constitutes  pitch,  which  is  withdrawn  and  employed 
for  making  pavements,  varnish,  etc. 

The  annexed  diagram  from  Ost's  "Lehrbuch  der  Technischen 
Chemie ' '  graphically  represents  the  preceding  outline  of  the  tar  distilla- 
tion process. 

4.  TREATMENT  OP  AMMONIACAL  LIQUOR. — The  ammoniacal  liquor  of 
the  gas-works  is  that  which  passes  out  continuously  from  the  scrubbers 
and  other  parts  of  the  process,  and  is  the  chief  source  of  nearly  all  the 


412   INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 


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DESTRUCTIVE  DISTILLATION  OF  COAL.  413 

ammonia  of  commerce.     According  to  Lunge,  ordinary  gas-liquor  con- 
tains the  following: 

(a)   Volatile  at  ordinary  temperatures. 

Ammonium  carbonates  (mono-,  sesqui-,  and  bi-). 

Ammonium  sulphide  (NH4)2S. 

Ammonium  hydrosulphide,  NH4.HS. 

Ammonium  cyanide. 

Ammonium  acetate  (?). 

Free  ammonia. 
(£)  Fixed  at  ordinary  temperatures. 

Ammonium  sulphate. 

Ammonium  sulphite. 

Ammonium  thiosulphate  (hyposulphite). 

Ammonium  thiocarbonate. 

Ammonium  chloride. 

Ammonium  thiocyanate  (sulphocyanide). 

Ammonium  ferrocyanide. 

The  salts  of  ammonia  that  are  volatile  are  readily  removed  from  the 
gas-liquor  upon  simply  boiling,  or  by  the  aid  of  steam.  The  fixed  am- 
monia salts  require  the  addition  of  chemical  agents — e.g.,  lime — to  break 
up  the  combination  and  liberate  the  ammonia  which  is  eventually  recov- 
ered. The  greater  the  amount  of  volatile  ammonia  and  less  the  amount 
of  the  non-volatile  compounds,  the  greater  the  value  the  liquor  has  for 
treatment. 

The  method  of  recovering  ammonia  at  a  London  works,  where  one 
hundred  thousand  gallons  of  liquor  are  treated  daily,  is  briefly  outlined 
as  follows :  The  liquor  is  pumped  into  a  large  settling-tank,  where,  after 
remaining  for  a  day  or  more,  it  is  pumped  into  a  "Coffey"  still,  thirty 
feet  high,  into  which  steam  at  two  atmospheres  pressure  is  blown.  By 
this  treatment  the  volatile  ammonium  compounds  are  separated  from 
the  water  and  the  non-volatile  compounds.  Carried  along  with  the 
steam,  the  volatile  compounds  pass  from  the  still  through  a  worm,  pro- 
vided with  half-inch  holes,  into  a  sheet-lead  saturator  filled  two-thirds 
with  140°  Twaddle  sulphuric  acid  in  water.  This  water  so  dilutes  the 
acid  that  it  prevents  the  ammonium  sulphate  from  crystallizing  within 
the  saturator.  After  saturation,  steam  is  blown  through  the  solution 
to  remove  hydrogen  sulphide,  which,  after  passing  through  a  condenser, 
is  burned ;  the  heat  generated  being  partly  utilized  in  the  production  of 
steam  for  the  operation.  The  saturated  liquid  is  run  off  into  leaden  pans 
placed  over  a  fire,  and  evaporated  to  such  a  point  that  the  sulphate  will 
crystallize  out.  The  residual  mother-liquor  is  made  use  of  in  the  dilu- 
tion of  the  sulphuric  acid  in  the  saturator. 

Without  going  into  the  details  of  construction  of  the  many  improve- 
ments made  in  the  apparatus  employed  for  the  recovery  of  ammonia,  it 
may  be  well  to  mention  the  apparatus  of  Griineberg  and  Blum,  Fig.  104. 
A  is  the  column,  B  the  economizer  through  which  the  gas-liquor  passes 
before  entering  the  still,  and  is  heated  by  means  of  steam  or  waste  gases. 


414  INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

C  is  the  pump  which  introduces  the  lime  into  the  lime-vessel  F.  D  is  the 
acid-tank  or  saturator.  The  gas-liquor  enters  the  still  at  the  top  and 
descends  from  chamber  to  chamber,  meeting  the  upward  current  of 
steam,  till  it  reaches  the  lime-decomposition-tank  F,  and  finally  the 
boiler  G.  In  this  is  a  peculiar  truncated  cone,  I,  over  which  flows  the 
liquor  from  step  to  step,  and  owing  to  the  increased  area  of  each  step 
the  liquor  becomes  thinner  and  thinner,  permitting  the  steam  to  act 
very  thoroughly.  The  ammonia  generated  passes  from  the  still  through 
the  pipe  P  to  the  saturator  D.  Waste  gases  collect  in  the  bell  q,  from 
which  they  are  led  to  the  economizer  B,  and  finally  burned. 


Feldmann's  apparatus  is  a  steam  still,  capable  of  recovering  both  the 
volatile  and  fixed  ammonia,  and  occupies  very  little  space.  It  consists 
of  a  chambered  column,  lime-tank,  and  an  auxiliary  column,  in  connec- 
tion with  feed-tanks,  economizer,  lime-pump,  and  saturator.  The  liquor 
flows  from  the  feed-tanks  through  the  economizer,  where  it  is  heated, 
to  the  top  of  the  main  column,  down  which  it  flows  successively  through 
the  chambers  in  which  it  is  boiled  into  the  ctecomposing-tank,  which 
contains  lime,  where  it  is  thoroughly  agitated  with  steam.  The  liquor 
flows  from  this  tank  to  the  auxiliary  column,  similar  to  the  first  one, 
where  the  little  ammonia  found  is  driven  out.  The  spent  liquor  collects 
in  the  lower  compartment,  from  which  it  constantly  flows  away.  Lunge 
states  that  an  apparatus  to  distil  from  eight  to  ten  tons  of  ammoniacal 


DESTRUCTIVE  DISTILLATION  OF  COAL.  415 

liquor  daily  occupies  a  space  of  seventeen  feet  by  thirteen  feet  by^ten 
feet. 

The  sulphate  of  ammonia  as  it  is  fished  from  the  saturators  is  allowed 
to  drain,  sometimes  slightly  washed  with  water,  and  sold  without  drying. 

III.  Products. 

Under  this  head  will  be  considered  the  more  important  products  that 
are  obtained  by  the  subsequent  treatment  of  the  main  fractions  of  the 
distillation  process  as  indicated  on  previous  pages. 

1.  FIRST  LIGHT  OIL  is  the  fraction  distilling  at  a  temperature  up  to 
170°  C.  It  includes  a  small  percentage  of  ammonia-liquor  which  is 
mechanically  contained  in  the  tar,  and  is  separated  from  the  tar  oils  by 
being  allowed  to  stand  and  settle  out,  when  it  is  drawn  off.  The  specific 
gravity  of  the  fraction  is  about  .975,  and  is  made  up  of  benzene,  toluene, 
and  higher  homologues,  with  phenol,  cresol,  naphthalene,  etc.  The  pro- 
ducts obtained  from  it  are  separated  by  redistilling  the  whole  fraction 
in  a  small  still  of  the  same  general  type  as  the  large  tar-still.  The  sepa- 
rate distillates  are  generally  as  follows: 

First  Light  Oil  up  to  170°  yields 

(a)  To  110°     "90  per  cent,  benzol." 

(6)    110°  to  140°   "50  per  cent,  benzol." 

(c)    140°   to  170°    solvent  naphtha. 

The  fraction  obtained  up  to  110°  is  chemically  washed,  being  agitated 
with  sulphuric  acid  of  1.84  specific  gravity  in  the  proportion  of  one 
pound  to  one  gallon  of  oil,  which  combines  with  the  bases,  dissolves 
resins,  etc.  The  agitation  is  carried  out  in  cast-iron  or  lead-lined 
wooden  tanks  securely  covered  to  prevent  loss  of  the  volatile  bodies,  and 
provided  with  mechanical  means  for  mixing.  This  is  completed  in  ten 
or  fifteen  minutes,  when  the  whole  is  allowed  to  stand  at  rest  for  an 
hour  or  more,  and  then  the  spent  acid  is  completely  removed.  The  oil 
is  now  thoroughly  washed  four  or  five  times  with  water,  until  no  color  is 
imparted  to  the  washings,  which  should  have  but  a  slight  acid  reaction. 
Agitation  is  again  continued,  but  with  a  ten  per  cent,  caustic  soda  solu- 
tion, afterwards  allowed  to  separate,  when  the  alkaline  solution  is  re- 
moved, and  the  oil  is  finally  washed  with  water  and  distilled,  either 
by  means  of  fire  or  steam. 

(a)  " Ninety  per  Cent.  Benzol.'1 — The  product  coming  over  at  110° 
is  designated  " ninety  per  cent,  benzol,"  from  the  fact  that  ninety  per 
cent,  by  volume  of  it  distils  before  the  thermometer  rises  above  100°  C. 
A.  H.  Allen  (Commercial  Organic  Analysis,  2d  ed.,  p.  489)  states:  "A 
good  sample  should  not  begin  to  distil  under  80°  C.,  and  should  not 
yield  more  than  twenty  to  thirty  per  cent,  at  85°,  or  much  more  than 

ninety  per  cent,  at  100°.  It  should  distil  below  120° The  actual 

percentage  composition  of  a  ninety  per  cent,  benzol  of  good  quality  is 
about  seventy  per  cent,  benzene,  twenty-four  per  cent,  toluene,  including 


416   INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

a  little  xylene,  and  four  to  six  per  cent,  of  bisulphide  of  carbon  and  light 
hydrocarbons.  The  proportion  of  real  benzene  may  fall  as  low  as  sixty 
or  rise  as  high  as  seventy  per  cent.  Ninety  per  cent,  benzol  should  be 
free  from  opalescence  and  colorless  ('water  white').  The  specific  gravity 
is  between  .88  and  .888  at  15.5°  C.  (  =  60°  F.),  but  this  is  not  a  true 

FIG.  105. 


guide  as  to  the  quality,  from  the  fact  that  bisulphide  of  carbon  (specific 
gravity  1.27)  and  light  hydrocarbons  (specific  gravity  .86)  sensibly 
affect  the  specific  gravity  of  the  benzol." 

(&)  "Fifty  per  Cent.  Benzol"  is  a  product  of  the  fraction  boiling 
from  110°  C.  up  to  140°  C.,  and  is  subjected  to  the  same  treatment  as 
the  previous  one.  The  specific  gravity  of  this  benzol  varies  from  .867 
to  .872  in  the  Scotch,  to  .878  to  .88  in  the  English,  samples.  Is  nearly 


DESTRUCTIVE  DISTILLATION  OF  COAL. 


417 


free  from  bisulphide  of  carbon,  and  contains  little  hydrocarbons,  while 
the  per  cent,  of  toluene  and  xylene  are  greater  than  in  the  ninety  per 
cent,  benzol. 

The  ' '  benzols ' '  on  the  American  market  at  present  are :  Benzol  pure, 
boiling  at  80°-83°  C.,  and  gravity  .881  to  .884;  benzol  one  hundred 
per  cent.,  gravity  .875  to  .884;  benzol  ninety  per  cent.,  gravity  .875  to 
.882;  benzol  fifty  per  cent.,  gravity  .871  to  .875;  benzol  160°  (ninety 
per  cent,  at  160°  C.),  gravity  .864  to  .870;  benzol  straw  color  (crude, 
ninety  per  cent,  benzol),  gravity  .862  to  .870. 

(c)  Solvent  Naphtha — so-called  from  the  use  to  which  it  is  put, — 
dissolving  caoutchouc  in  the  manufacture  of  water-proof  materials,  etc., 
—follows  the  benzols,  boiling  over  140°,  and  consists  of  xylene,  pseudo- 
cumene,  and  mesitylene.  In  some  works  the  distillation  of  this  fraction 
is  not  driven  to  the  end,  but  stopped  when  the  product  yields  ninety  per 
cent,  at  150°  C.,  the  residue  being  distilled  as  burning  naphtha  with  a 
specific  gravity  of  .90.  Lunge  states:  "From  the  product  distilled  up 
to  140°  may  be  extracted  sixty  or  seventy  per  cent,  of  fifty  per  cent, 
benzol,  twenty  to  twenty-five  per  cent,  of  carburetting  and  solvent 
naphtha,  five  to  eight  per  cent,  of  burning  naphtha.  The  product  dis- 
tilled between  140°  and  170°  yields  twenty-five  to  fifty  per  cent,  best 
naphtha,  fifty  to  twenty-five  per  cent,  burning  naphtha,  and  twenty-five 
per  cent,  residue  in  the  still."  The  separation  of  the  preceding  into 
benzene,  toluene,  xylene,  etc.,  for  the  use  of  the  color  manufacturer, 
is  not  ordinarily  carried  out  in  the  tar-distillery,  but  at  the  color- 
works,  in  especially  constructed  column  stills.  The  appearance  of  such 
a  benzene  rectification  still  is  shown  in  Fig.  105.  For  details  of  con- 
struction of  such  a  column  still,  see  Chapter  VI,  p.  247. 

The  following  table  (Lunge,  "Coal-Tar  and  Ammonia,"  2d  ed.,  p. 
476)  shows  the  yield  in  percentage  volumes  of  the  products  from  the 
light  tar  oils : 


COMMERCIAL  PRODUCTS. 

Initial 
boiling 
points. 

88.' 

93.' 

100.' 

no'. 

120.' 

130.' 

138'. 

149.' 

160.' 

171. 

"  Ninety  percent,  benzol" 
"Fifty  per  cent,  benzol" 
Toluol                         .    .    . 

82 
88 
100 

30 

65 
13 

90 
54 

74 
56 

90 
00 

Carburetting  naphtha  .    . 
Solvent  naphtha           .    . 

108 
110 

1 

35 
17 

71 

57 

84 
71 

97 
90 

138 

30 

71  5 

89 

2.  MIDDLE  OIL. — This  constitutes  the  second  main  fraction  in  the 
tar  distillation  process,  and  is  collected  between  170°  and  230°  C.,  yield- 
ing upon  further  treatment  two  very  important  and  valuable  products : 
liquid  and  solid  carbolic  acid  and  naphthalene,  both  of  which  find  their 
widest  application  in  the  artificial-color  industry,  although  large  quan- 
tities are  employed  for  many  other  purposes. 

While  this  fraction  is  coming  over  from  the  still,  no  cold  water  is 
allowed  to  run  into  the  condensing-tank,  for  the  reason  that  a  reduction 

27 


418  INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

of  temperature  to  the  point  at  which  solid  naphthalene  would  form  in 
the  condenser  is  to  be  avoided;  a  steam-pipe  is  generally  led  into  the 
tank,  and  the  water  brought  to  50°  or  60°,  thereby  keeping  crystalliz- 
able  matter  in  a  fluid  condition  and  continually  flowing. 

This  distillate  is  allowed  to  become  cold,  when  nearly  all  of  the 
naphthalene  separates  in  leaflets,  which  are  drained  and  pressed  to  expel 
the  remaining  portions  of  the  non-crystallizable  oil,  which  is  the  source 
of  the  carbolic  acid. 

1.  Carbolic  Acid. — The  above  oils  are  thoroughly  mixed  with  a  solu- 
tion of  caustic  soda   (specific  gravity  1.26)   in  a  tank  provided  with 
mechanical  agitators,  or  with  means  for  forcing  air  through  the  liquids. 
The  mixing  is  performed  at  a  temperature  of  from  40°  to  50°,  and  is 
completed  in  one  to  one  and  a  half  hours,  when,  after  standing  to  allow 
the  alkaline  liquors  to  subside,  they  are  drawn  off  and  cautiously  decom- 
posed by  adding  sulphuric  acid  till  the  liquor  has  an  acid  reaction,  when 
it  is  at  once  removed  to  avoid  the  crystals  of  sodium  sulphate  forming 
in  the  tank ;  the  carbolic  acid  is  allowed  to  stand  for  a  few  days  in  order 
that  any  sodium  sulphate  solution  remaining  may  separate  out,  when  it 
is  washed  with  water  and  finally  distilled  in  small  retorts,  yielding,  in 
the  first  fraction,  water  and  oil;  in  the  second,  crystallizable  oil,  from 
which  is  obtained  the  crystal  carbolic  acid  of  commerce ;  and  in  the  third 
fraction,  the  non-crystallizable  phenols,  or  liquid  carbolic  acid. 

That  part  of  the  mother-liquor  from  the  naphthalene  which  is  not 
acted  upon  by  the  caustic  soda  solution  added  to  remove  the  phenols  is 
returned  to  the  main  middle-oil  fraction  and  again  re-worked. 

Carbolic  Acid,  or  Phenol,  C6H6O  (or  C6H5OH). — All  compounds  con- 
taining the  group  OH  in  place  of  one  or  more  of  the  hydrogen  atoms  of 
benzene  (C0H6)  or  its  homologues,  are  designated  Phenols.  Carbolic 
acid  has  a  very  peculiar  and  characteristic  odor,  burning  taste,  is  poison- 
ous, and  has  preservative  properties;  the  odor,  however,  is  not  so  pro- 
nounced in  pure  as  in  impure  specimens.  The  specific  gravity  at  0°  is 
1.084 ;  it  crystallizes  in  colorless  rhombic  needles  which  melt  at  42°,  boiling 
at  182°,  and  is  not  decomposed  upon  distillation.  At  ordinary  tempera- 
ture it  dissolves  in  water  with  difficulty  (1 : 15),  but  is  soluble  in  alcohol, 
ether,  glacial  acetic  acid,  and  glycerine  in  all  proportions.  Upon  expo- 
sure to  light  and  air  it  deliquesces,  and  acquires  a  pinkish  color.  The 
most  extensive  use  made  of  it  is  as  a  raw  material  in  the  manufacture  of 
many  of  the  artificial  coloring  matters, — picric  acid,  used  as  a  yellow 
dye,  and  which  finds  considerable  application  in  the  manufacture  of  a 
number  of  high  explosives.  Large  quantities  of  various  qualities  of  car- 
bolic acid  are  consumed  annually  for  antiseptic  purposes,  both  for 
domestic  use  and  in  surgery. 

2.  Naphthalene. — The  crude  crystals  which  were  obtained  when  the 
middle-oil  fraction  was  allowed  to  cool,  and  also  from  the  treatment  by 
distillation  of  the  unchanged  oil  from  the  carbolic  acid  separation,  are 
purified  by  fusing  and  mixing  thoroughly  with  caustic  alkali,  if  impure, 
followed  by  a  washing  with  hot  water,  and  afterwards  with  sulphuric 
acid;  if  the  naphthalene  operated  upon  is  of  a  better  quality,  the  alka- 


DESTRUCTIVE  DISTILLATION  OF  COAL. 


419 


FIG.  106. 


line  treatment  may  be  dispensed  with,  and  the  refining  commenced  with 
the  acid,  which  is  of  1.453  specific  gravity;  Lunge  states,  however,  that 
this  is  too  weak,  and  recommends  an  acid  of  1.70  specific  gravity,  1.84 
specific  gravity  being  still  better.  The  amount  of  acid  used  varies  from 
five  to  ten  per  cent. ;  the  mixing  being  performed  in  lead-lined  tanks, 
after  which  it  is  washed  with  water  several  times,  and  to  remove  the 
remaining  traces  of  acid  weak  caustic  liquor  is  used.  The  naphthalene 
thus  purified  is  sublimed  in  barrels  hung  over  melting-pots  suitably 
mounted,  or  in  frame  or  brick  chambers  connected  by  proper  openings 
with  an  iron  melting-pan,  the  general  construction  of  which  is  shown 
in  Fig.  106.  The  best  naphthalene  is  produced  by  distillation  from  stills, 
which  are  made  shallow,  with  a  very  high  dome.  Larger  quantities  are 
handled  by  this  method  than  by  subliming. 

Naphthalene,  C10HS,  is  one  of  the  principal  constituents  of  coal-tar, 
occurring  in  it  in  various  proportions  from  five  to  ten  per  cent. ;  it  is 
also  formed  when  the  vapors  of  organic  substances  are  passed  through 
tubes    heated    to    redness.       The 
specific     gravity     of     naphthalene 
when  solid  is  1.158,  at  its  melting 
point   (79.2°)   it  is  0.978;  it  boils 
at  216.6°  C.    The  odor  is  pleasant, 
though    characteristic ;    volatilizes 
to  some  extent  at  ordinary  temper- 
ature, but  readily  in  the  vapor  of 
boiling     water.       Crystallizes     in 
large,  silvery-brilliant,  thin  rhom- 
bic plates,   which  are  faintly  sol- 
uble in  hot,  but  insoluble  in  cold 

water,  though  easily  in  methyl  and  ethyl  alcohols,  chloroform,  ether,  ben- 
zene, etc.  The  commercially  sublimed  naphthalene  is  from  seventy  to 
ninety-nine  per  cent.  pure.  Industrially,  it  is  employed  in  the  manufac- 
ture of  a  large  series  of  coloring  matters;  as  an  enricher  ("carburetter") 
of  illuminating  gas ;  and  when  specially  refined,  as  a  substitute  for  ordi- 
nary camphor  in  preventing  the  ravages  of  insects,  etc.,  in  woollen  goods. 

3.  CREOSOTE  OIL,  OR  HEAVY  OIL,  constitutes  the  third  main  fraction, 
and  is  generally  collected  from  230°  to  270°  C.,  or  until  it  is  noticed 
that  solid  matters  begin  to  crystallize,  which  indicates  that  the  anthra- 
cene is  commencing  to  distil.  In  order  to  prevent  any  cresols  from  con- 
taminating the  phenol  and  naphthalene  of  the  previous  fraction,  that 
fraction  is  not  driven  to  completeness,  which  precludes  the  possibility 
of  any  of  the  heavy  oil  passing  over.  Any  naphthalene  contained  in  this 
fraction  is  recovered  by  crystallizing  and  pressing,  the  residual  oil  not 
being  subjected  to  further  treatment  but  employed  directly. 

The  oil  has  a  greenish-yellow  color,  and  is  very  fluorescent,  which  in- 
creases in  intensity  upon  exposure  to  light  and  air.  By  transmitted 
light  it  is  dark  red,  and  by  reflected  light  the  appearance  is  bottle-green. 
The  odor  is  unpleasant  and  extremely  characteristic.  It  is  heavier  than 
water,  the  last  portion  coming  from  the  still  being  as  high  in  specific 


420  INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

gravity  as  1.10.  Creosote  oil  has  been  found  to  contain  naphthalene, 
anthracene,  phenanthrene,  phenol,  cresol,  etc.,  with  many  other  bodies 
but  little  known.  It  finds  its  widest  application  in  the  creosoting  or 
preservation  of  timber;  although,  to  a  limited  extent,  it  has  been  em- 
ployed as  a  fuel,  and  for  the  production  of  illuminating  gas,  softening 
hard  pitch,  as  a  lubricant,  for  lamp-black  production,  etc. 

The  process  of  impregnating  timber  with  coal-tar  oils,  with  the  view 
of  preserving  it  against  decay,  dates  from  1838,  when  a  patent  was 
granted  to  John  Bethell.  This  process  consists  essentially  of  exhausting 
the  already  seasoned  timber  of  air  and  moisture  in  a  vacuum  main- 
tained by  means  of  an  air-pump ;  when  the  exhaustion  is  complete,  the 
tar  oil  is  allowed  to  enter  the  vessel,  when  it  is  at  once  absorbed  by  the 
pores  of  the  wood.  Various  processes  have  been  suggested  from  time  to 
time,  but  those  which  have  given  the  most  complete  satisfaction  are 
nearly  all  based  upon  the  one  above  mentioned.  In  the  experimental 
work  of  the  Forest  Service  of  the  U.  S.  Department  of  Agriculture  on 
tie  preservation  a  simpler  and  from  many  points  of  view  a  better  process 
has  been  used  in  recent  years.  The  ties  are  put  into  open  tanks  con- 
taining creosote  oil,  in  which  they  are  completely  immersed,  and  the  con- 
tents of  the  tank  are  gradually  heated  by  closed  coils  carrying  steam 
under  pressure  to  a  point  at  which  moisture  is  eliminated  as  steam. 
After  the  lapse  of  sufficient  time  to  allow  the  moisture  and  air  from 
the  pores  of  the  wood  to  escape  in  this  way,  the  hot  ties  are  quickly 
transferred  to  tanks  containing  cold  creosote  oil,  in  which  they  remain 
until  entirely  cooled.  In  this  way  the  oil  is  drawn  into  the  pores  of  the 
wood  as  they  contract  and  the  wood  fibre  is  not  weakened  by  steaming 
and  vacuum  treatment. 

Until  recently  in  choosing  a  creosote  oil  for  wood  preservation  most 
experts  valued  the  tar  acids  and  naphthalene  as  the  important  constit- 
uents, and  demanded  definite  percentages  of  each.  Now  the  weight 
of  opinion  is  in  favor  of  the  heavy  oils,  which  come  over  after  naphtha- 
lene in  the  distillation,  and  considers  the  naphthalene  as  of  small  value. 
This  is  because  naphthalene  is  volatile  at  all  temperatures,  and  will 
entirely  disappear  from  the  wood  in  course  of  time.  As  an  illustration 
of  this  may  be  quoted  from  Circular  141  of  the  Forest  Service,  U.  S. 
Department  of  Agriculture,  entitled  "Wood  Paving  in  the  United 
States, ' '  the  specifications  of  the  City  of  Minneapolis  for  creosote  oil  for 
wooden  block  impregnation.  These  state  "the  specific  gravity  of  the 
oil  at  20°  C.  shall  be  at  least  1.09;  the  oil  shall  be  completely  liquid  at 
25°  C.,  and  show  no  deposit  on  cooling  to  22°  C. ;  it  shall  not  contain 
more  than  two  per  cent,  of  water  nor  more  than  three  per  cent,  of 
matter  insoluble  in  absolute  alcohol  or  benzene;  on  distillation  up  to 
150°  C.  nothing  must  come  off,  up  to  170°  C.  two  per  cent,  up  to  210° 
from  six  to  eight  per  cent.,  up  to  235°  from  twenty  to  thirty  per  cent., 
up  to  315°  from  forty  to  fifty  per  cent.,  up  to  355°  from  sixty  to  eighty 
per  cent."  It  will  be  seen  that  this  calls  for  a  relatively  heavy  oil  con- 
taining high  boiling  fractions. 

Prof.  Grellert  Alleman  also,  in  discussing  the  results  of  the  extrae- 


DESTRUCTIVE  DISTILLATION  OF  COAL. 


421 


FIG.' 107. 


C 


tion  of  oil  from  ties  and  paving  blocks  which  had  been  in  use  for  a 
term  of  years,  says:  "Perhaps  the  most  striking  thing  is  the  disappear- 
ance of  the  tar  acids.  It  is  certainly  conservative  to  place  the  original 
tar  acid  content  at  five  per  cent.,  yet  the  extracted  oil  showed  but  a  tenth 
of  this  amount.  ...  It  appears  therefore  that  light  oils  boiling 
below  205°  C.  will  not  remain  in  timber  but  that  heavy  oils  containing 
a  high  percentage  of  anthracene  oil  will  remain  almost  indefinitely  and 
protect  the  wood  from  decay  and  boring  animals.  It  is  probable  that 
naphthalene  stays  in  wood  for  many  years,  but  whether  it  is  as  valuable 
as  anthracene  oil  is  open  to  question.  The  value  of  the  tar  acids  has 
apparently  been  overestimated  by  many  persons, 
for  although  it  has  not  been  proved  that  they  are 
valueless,  they  have  been  shown  to  possess  poor 
staying  qualities." 

4.  ANTHRACENE  OIL. — The  fraction  distilling 
from  270°  C.  and  over  consists  of  that  portion  of 
the  tar  which  is  made  up  of  bodies  possessing  the 
highest  boiling  points,  and  is  distinguished  from 
the  heavy  oil  fraction  by  a  separation,  on  cooling, 
of  solid  matters.  In  it  have  been  found  naph- 
thalene, methyl-naphthalene,  anthracene,  phenan- 
threne,  methyl-anthracene,  pyrene,  carbazol,  etc. 
With  the  exception  of  methyl-naphthalene,  which 
is  a  liquid,  all  the  others  are  solids  at  ordinary 
temperature,  but  which  have  high  melting  points. 

The  separation  of  the  crude  anthracene  from 
the  distillate  is  accomplished  by  cooling  or  crys- 
tallizing, and  pressing.  The  cooling  takes  place 
in  large,  shallow  iron  pans,  either  spontaneously 
or  by  refrigeration,  when  the  semi-solid  mass  is 
transferred  to  bag  filters,  closed  at  the  lower  end, 
and  connected  by  means  of  nipples  at  the  upper 
end  to  a  pipe  for  conducting  compressed  air, 
which  acts  in  driving  the  liquid  or  non-solidi- 
fying portion  out,  and  leaving  the  mass  nearly  dry.  By  using  filter- 
presses  instead  of  the  above,  a  large  and  better  yield  can  be  obtained 
in  a  shorter  time.  The  crude  anthracene  is  placed  in  cloths  and 
subjected  to  a  gradually-increasing  pressure  in  a  vertical  or  horizontal 
hydraulic  press,  the  plates  of  which  are  so  constructed  as  to  be  heated 
by  steam,  or  the  whole  press  may  be  enclosed  in  a  chest  to  which  steam 
can  be  admitted.  Fig.  107  illustrates  the  general  arrangement  of  a 
press  suited  to  the  purpose.  The  use  of  heat  in  the  pressing  is  to  cause 
those  bodies  which  have  a  lower  melting  point  than  that  of  the  anthra- 
cene to  be  easily  removed.  The  yield  of  anthracene  by  hot-pressing  only 
comes  up  to  about  thirty  to  thirty-two  per  cent,  of  the  oil  in  winter, 
and  thirty-three  to  thirty-six  per  cent,  in  summer  (Lunge).  The  pressed 
anthracene  is  ground  to  a  fine  powder,  and  washed  with  solvent  naphtha 
(which  removes  the  coal-tar  oils)  in  either  a  horizontal  or  vertical  air- 


422  INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

tight  boiler,  fitted  with  a  steam  coil,  and  provided  with  a  mechanical 
agitator.  The  mixing  requires  several  hours  with  gentle  heat,  when 
the  whole  is  forced  by  compressed  air  to  a  closed  filter,  which  separates 
the  now  washed  anthracene  from  the  naphtha. 

A  still  purer  anthracene  is  obtained  by  submitting  this  product  to 
sublimation  with  the  aid  of  steam.  For  this  purpose  the  apparatus 
shown  in  Fig.  108  is  employed.  The  anthracene  is  melted  in  an. iron 
pan,  and  over  the  surface  of  the  melted  mass  superheated  steam  is  blown. 
The  anthracene  vapors  are  carried  by  the  steam  into  a  cooling  chamber, 
where  they  are  condensed  by  coming  in  contact  with  a  spray  of  cold 
water. 

The  anthracene  oils  from  the  first  draining  of  crude  material  are 
usually  re-distilled  in  order  that  the  anthracene  contained  in  them  may 
be  recovered.  Graham's  process  (Chem.  News,  xxxiii,  pp.  99,  168)  for 
this  is  to  distil  about  fifteen  hundred  gallons  of  the  filtered  oils  from  a 

FIG.  108. 


clean  tar-still  until  crystals  of  anthracene  are  noticed,  when  a  sample 
of  the  distillate  is  allowed  to  cool,  at  which  point  the  operation  is 
stopped,  and  the  residue  in  the  still  is  run  out  and  allowed  to  become 
cold,  when  the  product  separates  out.  This  is  filtered  and  pressed  in 
the  manner  above  described  for  the  first  crystallization. 

The  oils  which  yield  no  more  anthracene  when  subjected  to  further 
treatment  are  added  to  the  creosote  oils,  or  else  employed  to  soften 
pitch,  etc. 

Anthracene,  C14H10,  is  found  under  similar  conditions  to  those  giving 
rise  to  naphthalene,  and  was  discovered  in  1832  by  Dumas  and  Laurent, 
while  Fritzsche  was  the  first  to  find  it  in  coal-tar,  in  which  it  occurs  as  a 
characteristic  constituent.  When  pure,  it  crystallizes  in  white,  lustrous, 
rhombic  plates,  which  exhibit  a  beautiful  violet  fluorescence.  Melts 
from  210°  to  213°  C.,  subliming  at  about  the  same  temperature  in  small 
scales.  It  is  insoluble  in  water,  sparingly  in  alcohol,  while  benzene, 
essential  oils,  light  tar  oils,  and  hot  alcohol  dissolve  varying  quantities. 
When  oxidized  it  yields  anthraquinone,  which  is  further  treated  in  the 
processes  for  the  production  of  the  valuable  alizarine  and  other  coal-tar 
colors,  and  which  forms  practically  the  only  utilization  for  anthracene. 


DESTRUCTIVE  DISTILLATION  OF  COAL.  423 

5.  PITCH. — By  pitch  is  understood  the  residue  remaining  in  the  still 
after  nearly  all  the  volatile  constituents  have  been  driven  off.  For- 
merly, what  remained  in  the  still  after  the  light  oils  were  distilled  was 
called  asphalt,  and  was  equivalent  to  about  eighty  per  cent,  of  the  tar, 
consequently  it  contained  those  constituents  mentioned  in  the  middle 
oil  and  creosote  oil  fractions,  with  the  anthracene.  This  method  of 
fractionation,  however,  is  not  followed,  but  the  distillation  is  generally 
carried  to  that  point  when  the  distillate  shows  a  specific  gravity  of  1.09, 
when  soft  pitch  will  result.  If  the  distillation  is  carried  further,  or 
until  it  has  a  specific  gravity  of  1.12,  hard  pitch  is  obtained.  In  some 
cases  the  distillation  is  pushed  as  far  as  the  still  will  stand  with  safety, 
in  which  case  no  more  volatile  bodies  remain  and  a  coke  virtually  re- 
mains. As  a  rule,  a  moderately  hard  pitch  is  made,  which  is  run  into 
casks  or  barrels  directly  from  the  still. 

The  utilization  of  the  pitch  is  carried  out  in  several  ways:  in  the 
manufacture  of  patent  fuel  (briquettes)  when  incorporated  with  coal- 
dust  or  coke-refuse.  This  industry,  which  has  had  an  extensive  devel- 
opment in  Europe,  has  in  the  last  few  years  assumed  importance  in  the 
United  States.  Briquettes  contain  from  six  to  eight  per  cent,  of  pitch, 
according  to  the  amount  of  pressure  employed  in  their  manufacture. 

In  deciding  the  value  of  a  given  pitch  or  tar  for  briquetting  purposes 
three  points  may  be  noted:*  1.  The  pitch  or  tar  is  distilled  and  all 
oils  coming  over  below  270°  C.  are  rejected  as  of  no  value  for  briquet- 
ting.  2.  The  flowing  point  of  the  portion  to  be  used  in  briquetting  is 
determined.  This  should  generally  be  not  less  than  70°  C.  3.  The  pitch 
is  extracted  with  carbon  disulphide.  The  smaller  the  amount  of  resid- 
ual carbon  the  more  satisfactory  the  pitch. 

IV.  Analytical  Tests  and  Methods. 

1.  VALUATION  OF  TAR  SAMPLES. — Practically,  the  most  efficient 
method  to  follow  for  the  determination  of  the  value  of  tar  samples  is 
to  distil  twenty  or  thirty  gallons  from  a  small  still,  in  the  same  manner 
and  under,  as  far  as  possible,  the  same  conditions  as  is  practised  in  the 
distillation  of  tar  on  a  Large  scale.  The  products  are  weighed  and  meas- 
ured. When  a  small  still  is  not  accessible,  recourse  must  be  had,  for 
laboratory  purposes,  to  the  following  method,  which  gives  excellent  re- 
sults if  carefully  attended :  f  "  Two  hundred  and  fifty  cubic  centimetres, 
or  ten  ounces  measure,  of  the  tar  is  placed  in  a  retort  which  it  only  one- 
third  fills,  so  as  not  to  spoil  the  distillate  if  there  is  much  frothing  during 
distillation.  The  retort  should  be  supported  on  a  cup-shaped  piece  of 
coarse  wire  gauze,  placed  in  an  aperture  in  a  sheet-iron  plate.  Over  the 
retort  is  placed  a  dome,  made  by  removing  the  bottom  from  a  tin  can  or 
bottle,  and  cutting  out  a  piece  of  the  side  to  allow  the  neck  of  the  retort 
to  pass  through.  This  contrivance  confines  the  heat,  and  prevents  the 
distillate  or  heavy  vapor  from  falling  back."  .  .  .  "The  products 

*  U.  S.  Geological  Survey,  Bulletin  343,  p.  41,  1908. 

f  A.  H.  Allen,  Commercial  Organic  Analysis,  3d  ed.,  vol.  ii,  Part  ii,  p.  52. 


424  INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

obtained  by  the  distillation  are:  (1)  Ammoniacal  liquor;  (2)  total  light 
oils;  (3)  creosote  oil;  (4)  anthracene  oils;  and  (5)  pitch.  In  obtain- 
ing these  fractions,  the  character  of  the  distillate  is  amply  sufficient  to 
indicate  the  point  at  which  the  receiver  should  be  changed.  No  ther- 
mometer is  necessary,  nor  any  condensing  arrangement  to  be  attached  to 
the  retort.  The  lamp  being  lighted  (a  powerful  Bunsen),  the  ammo- 
niacal  liquor  and  naphtha  are  collected  together  in  a  graduated  cylinder, 
which  is  changed  when  a  drop  of  the  distillate — collected  in  a  test-tube 
of  water — begins  to  sink.  After  standing  to  allow  perfect  separation 
of  the  ammoniacal  liquor  and  light  oils,  the  volume  of  each  is  observed, 
and,  if  desired,  the  strength  of  the  former  can  be  ascertained  in  the  usual 
way  by  distillation  with  lime  and  titration  of  the  distillate.  The  quan- 
tity of  light  oils  is  too  small  to  aJIow  of  any  further  fractionation  for 
benzols,  etc. 

"The  next  fraction  of  the  distillate  consists  of  creosote  oil.  At  first 
it  will  contain  much  naphthalene,  and  will  probably  solidify  in  white 
crystals  on  cooling,  but  afterwards  a  more  fluid  distillate  is  obtained. 
At  a  still  later  stage,  a  drop  of  the  distillate  collected  on  a  cold  steel 
spatula  will  be  found  to  deposit  amorphous  solid  matter  of  a  yellow  or 
greenish-yellow  color,  when  the  receiver  is  again  changed,  the  fraction 
measured,  and  if  desired,  assayed  for  carbolic  acid  and  naphthalene. 

"The  next  fraction  of  the  distillate  is  rich  in  anthracene,  and  not 
unfrequently  condenses  in  the  neck  of  the  retort  as  a  yellow,  waxy  sub- 
stance, which  may  be  melted  out  by  the  local  application  of  a  small 
Bunsen  flame. 

"The  collection  of  anthracene  oil  is  complete  when  no  more  distil- 
late can  be  obtained,  and  the  pitch  intumesces  and  gives  off  heavy  yellow 
fumes.  The  distilled  fraction  is  then  measured  and  cooled  thoroughly, 
and  the  resultant  pasty  mass  pressed  between  folds  of  blotting-paper, 
weighed,  and  assayed  for  real  anthracene  by  the  anthraquinone  test. 
The  result  is  calculated  into  crude  anthracene  at  thirty  per  cent.,  a 
standard  which  is  generally  adopted  by  the  manufacturers. 

"When  the  distillation  for  anthracene  oil  is  complete,  the  retort  may 
be  allowed  to  cool,  and  when  almost  cold  its  body  should  be  plunged 
into  cold  water.  This  produces  a  rapid  surface-cooling  and  shrinking  of 
the  pitch  from  the  glass,  which  may  then  be  broken  away  and  removed 
by  gentle  tapping,  leaving  the  cake  of  pitch  clean  and  ready  for  weigh- 
ing." 

2.  SPECIAL  TESTS  FOR  TAR  CONSTITUENTS. — (a)  Benzol. — The  follow- 
ing method,  from  Allen,*  is  the  most  convenient  for  testing  benzol,  and 
is  reasonably  accurate.  One  hundred  cubic  centimetres  of  the  benzol 
to  be  tested  is  measured  in  an  accurately  graduated  cylinder,  and  poured 
thence  into  a  tubulated  retort,  of  such  a  size  as  to  be  capable  of  retain- 
ing two  hundred  cubic  centimetres,  or  eight  fluidounces,  when  placed 
in  the  ordinary  position  for  distillation.  A  delicate  thermometer  is  fitted 
in  the  tubulure  of  the  retort  by  a  cork,  so  that  it  may  be  vertical  and 
the  lower  end  of  the  bulb  be  three-eighths  of  an  inch  distance  from  the 
bottom  of  the  retort.  The  neck  of  the  retort  is  then  inserted  into  the 

*  Commercial  Organic  Analysis,  3d  ed.,  vol.  ii,  Part  ii,  p.  185. 


DESTRUCTIVE  DISTILLATION  OF  COAL.  425 

inner  tube  of  a  Liebig's  condenser,  and  pushed  down  as  far  as  it  will 
go.  The  condenser  should  be  from  fifteen  to  eighteen  inches  in  length, 
and  well  supplied  with  cold  water.  The  neck  of  the  retort  should  not 
project  too  far  into  the  condenser;  if  necessary  it  should  be  cut  short. 
No  cork  or  other  connection  is  necessary  between  the  retort-neck  and 
condenser-tube.  Before  use,  the  tube  of  the  condenser  should  be  rinsed 
with  a  little  of  the  sample,  and  allowed  to  drain,  or  some  of  the  benzol 
may  be  sprayed  through  it.  The  graduated  cylinder  employed  for 
measuring  out  the  sample  is  next  placed  under  the  farther  end  of  the 
condenser-tube  in  such  a  manner  as  to  catch  all  the  distillate,  while 
allowing  it  to  drop  freely.  The  retort  is  then  heated  by  the  naked  flame 
of  a  Bunsen  burner  (which  can  be  conveniently  placed  in  a  tin  basin 
containing  sand  or  sawdust,  in  order  to  absorb  the  benzol  in  the  event 
of  the  retort  cracking).  The  flame  should  be  small,  about  the  size  and 
shape  of  a  filbert,  and  when  the  distillation  of  the  benzol  commences 
must  be  so  regulated  that  the  condensed  liquid  shall  fall  rapidly  in 
distinct  drops,  not  in  a  trickle  or  a  continuous  stream. 

When  the  distillation  commences  the  flame  is  regulated,  if  necessary, 
and  the  rise  of  the  thermometer  carefully  watched.  The  moment  it 
registers  a  temperature  of  85°  C.  the  flame  is  extinguished.  Four  or 
five  minutes  are  allowed  for  the  liquid  in  the  condenser  to  drain  into 
the  measuring  cylinder,  and  then  the  volume  of  the  distillate  is  carefully 
read  off  and  recorded.  The  lamp  is  then  relighted  and  the  distillation 
continued  till  the  thermometer  rises  to  100°  C.,  when  the  gas  is  turned 
off  as  before,  and  the  volume  of  the  distillate  read  off,  after  allowing 
time  for  drainage.  The  residual  liquid  in  the  retort  is  allowed  to  cool, 
and  is  then  poured,  to  the  last  drop,  into  the  measuring  cylinder.  A 
deficiency  from  the  one  hundred  cubic  centimetres  originally  taken  will 
generally  be  observed.  The  difference  between  the  collective  volume 
after  distillation  and  that  of  the  original  sample  is  to  be  added  to  the 
measure  of  the  distillate  collected  at  each  temperature,  and  the  cor- 
rected volumes  reported  as  the  " strength"  of  the  benzol  examined.  As 
a  matter  of  fact,  the  loss  of  volume  by  distillation  is  due  far  more  to 
expulsion  of  acetylene  and  other  gases  than  to  actual  loss  of  benzol. 
Lunge,  in  "Coal-Tar  and  Ammonia"  (2d  edition,  1887),  gives  much 
practical  information  bearing  upon  this  subject,  which,  in  matters  re- 
lating to  the  production  and  sale  of  benzols,  etc.,  in  Europe,  has  received 
considerable  attention. 

(&)  Phenols. — The  detection  of  phenol  is  in  many  cases  of  consider- 
erable  importance,  and  several  reactions  have  been  proposed ;  the  follow- 
ing are  taken  from  Allen,  who  has  personally  verified  them.  Upon  add- 
ing a  drop  of  a  dilute  aqueous  solution  of  phenol  to  a  small  quantity  of 
a  solution  made  up  of  one  gramme  of  molybdic  acid  in  ten  cubic  centi- 
metres of  sulphuric  acid,  a  yellow-brown  coloration  is  produced,  which 
changes  to  a  permanent  purple  tint.  Many  substances  interfere  with 
this  reaction  owing  to  the  fact  that  it  depends  upon  the  reduction  of 
the  molybdic  acid. 

Ferric  chloride  gives  a  fine  violet  color,  by  which  one  part  of  phenol 
is  detected  in  three  thousand  of  water.  Resorcin  and  hydroquinone  give 


426  INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

similar  reactions.  Sodium  chloride,  nitre,  or  boric  acid  is  unobjection- 
able, but  most  mineral  and  organic  acids,  acetates,  borax,  sodium  phos- 
phate, glycerine,  alcohol,  and  ether  hinder  the  reaction.  If  an  aqueous 
solution  of  phenol  is  warmed  with  ammonic  hydroxide  and  a  solution  of 
sodium  hypochlorite,  a  permanent  deep-blue  color  is  obtained,  which 
is  turned  red  upon  addition  of  acids.  One  part  of  phenol  in  five  thou- 
sand of  water  will  react  if  twenty  cubic  centimetres  are  used,  weaker 
solutions  also,  after  a  time.  A  modification  of  the  above  is*  to  add  to 
fifty  cubic  centimetres  of  the  phenol  solution  five  cubic  centimetres  of 
dilute  ammonia,  and  then,  slowly,  fresh  and  dilute  bromine-water,  when 
a  fine  blue  tint  is  produced  which  is  permanent.  Bromine  vapors  will 
answer  instead  of  bromine-water.  .* 

If  to  a  solution  of  phenol  a  drop  of  aniline  be  added,  and  then  a 
solution  of  sodium  hypochlorite,  yellow  striae  are  produced  which  change 
to  blue.  This  test  is  very  delicate. 

Upon  the  gradual  addition  of  bromine  to  a  solution  of  phenol  a  white 
turbidity  (mono-brom-phenol,  C6H4BrOH)  is  formed.  If  the  solution 
is  dilute  no  precipitate  occurs,  but  upon  the  addition  of  more  bromine, 
di-brom-phenol  (C6H3Br2OH)  is  formed;  upon  further  addition  of  bro- 
mine a  very  bulky  precipitate  is  produced,  which  is  separated  as  the 
insoluble  and  characteristic  tri-brom-phenol  (C6H.,Br3OII).  This  de- 
termination of  phenol  was  first  suggested  by  Landolt,  though  brought 
•to  perfection  and  used  as  a  volumetric  method  by  Koppeschaar  (Z.  a. 
Chemie,  xvi,  233). 

For  the  assay  of  carbolic  acid  the  specific  gravity  is  always  noted, 
which  ranges  between  1.04  and  1.065;  the  lower  figure  indicates  a  sus- 
picious sample,  and  represents  light  tar  oils.  Water  is  estimated  by 
agitating  the  sample  with  half  its  volume  of  a  saturated  solution  of 
salt,  the  loss  of  volume  indicates  the  amount  of  water  originally  present. 
To  ascertain  the  quality  of  crude  carbolic  acid  and  probable  yield  of 
crystallized  phenol,  the  following  method  of  Lowe  (Allen,  Com.  Org. 
Anal.,  3d  ed.,  vol.  ii,  Part  ii,  p.  252)  is  used.  One  hundred  cubic  cen- 
timetres are  distilled  and  the  distillate  collected  in  graduated  tubes. 
Water  first  distils,  and  is  followed  by  an  oily  fluid;  this  is  allowed  to 
stand,  when  the  volume  of  water  is  read  off.  If  the  oily  liquid  floats  on 
the  water,  it  contains  light  oil  of  tar.  It  should  be  heavier  than  water, 
in  which  case  it  may  be  regarded  as  hydrated  acid  containing  about  fifty 
per  cent,  of  real  carbolic  acid.  The  next  portion  of  the  distillate  con- 
sists of  anhydrous  acid,  and  when  it  measures  62.5  per  cent,  the  receiver 
is  again  changed.  The  residue  in  the  retort  consists  wholly  of  cresylic 
acid  and  still  higher  homologues  of  carbolic  acid.  The  62.5  per  cent,  of 
anhydrous  acid  contains  variable  proportions  of  carbolic  and  cresylic 
acid.  These  may  be  approximately  determined  by  ascertaining  the 
solidifying  point,  which  should  be  between  15.o°  and  24°  C.,  and  by 
making,  with  known  proportions  of  carbolic  and  cresylic  acids,  a 
standard  sample  that  will  have  the  same  solidifying  point. 

(c)  Naphthalene. — The  assay  of  this  substance  generally  consists  in 
submitting  about  twenty-five  grammes,  wrapped  in  several  folds  of 


DESTRUCTIVE  DISTILLATION  OF  COAL.  427 

filter  or  bibulous  paper,  to  pressure  in  a  copying-press  until  the  exuda- 
tion of  any  oil  ceases,  when  the  cake  is  again  weighed,  and  if  desirable, 
distilled  from  a  small  retort.  Good  samples  should  not  distil  below  210°, 
and  should  yield  ninety  per  cent,  of  distillate  before  the  temperature 
exceeds  225°  C.  Upon  warming  sublimed  naphthalene  with  pure  sul- 
phuric acid  in  a  test-tube,  the  solution  should  remain  colorless.  If  one 
per  cent,  of  impurity  is  present,  a  decided  pinkish  tint  is  observed, 
which  is  darker  the  greater  the  amount.  The  determination  of  the 
specific  gravity,  the  melting  point  (79°  C.),  and  the  boiling  point  (216° 
to  218°  C.)  are  made  by  the  usual  methods. 

(d)  Creosote  Oils. — The  characteristics  of  this  fraction  were  pre- 
viously indicated.  The  specific  gravity  is  determined  either  by  the 
bottle  or  hydrometer;  in  cases  where  the  sample  contains  much  naph- 
thalene, the  specific  gravity  bottle  is  filled  and  the  contents  allowed  to 
become  solid,  when  the  stopper  is  worked  in.  A  sample  should  become 
quite  clear  upon  warming  to  about  38°  C.,  and  ought  not  become  turbid 
till  cooled  to  32°  C.  The  liquefying  point  is  determined  by  transfer- 
ring a  sample  of  the  oil  to  a  test-tube,  immersing  a  thermometer,  and 
warming  gently  till  it  becomes  liquid.  The  point  of  turbidity  is  simi- 
larly observed,  by  allowing  the  tube  to  cool  spontaneously.  For  the 
determination  of  the  naphthalene,  one  hundred  grammes  are  chilled  to 
4.5°  C.  in  a  small  beaker,  then  transferred  to  a  cloth  filter,  placed 
in  a  funnel  provided  with  means  for  cooling  to  4.5°  during  filtration. 
The  filter  and  contents  are  removed  and  quickly  pressed  between  bibu- 
lous paper  in  a  copying-press,  when  the  cake  is  pressed  and  weighed. 

(e}  Anthracene. — Commercial  anthracene  contains  a  very  variable 
percentage  of  real  anthracene,  the  usual  proportions  being  from  thirty 
to  forty  per  cent.,  though  formerly  fifteen  per  cent,  was  common,  and 
special  lots  now  assay  over  eighty  per  cent.  The  value  of  anthracene 
does  not  entirely  depend  upon  the  amount  of  real  anthracene  alone, 
but  also  upon  the  freedom  from  objectionable  impurities.  In  testing 
for  paraffin,  ten  grammes  of  the  sample  are  taken  and  treated  with  two 
hundred  grammes  of  concentrated  sulphuric  acid,  heated  on  a  water- 
bath  for  about  ten  minutes,  or  until  the  anthracene  is  dissolved,  when 
any  paraffin  will  rise  to  the  surface  in  oily  globules.  The  solution  is 
now  poured  cautiously  into  a  tall  beaker  containing  five  hundred  cubic 
centimetres  of  water,  stirred,  and  cooled,  when  the  paraffin  rises  and 
solidifies  on  the  surface;  it  is  washed  with  water,  dried  between  filter- 
paper  and  weighed. 

By  the  conversion  of  anthracene  into  anthraquinone  the  most  satis- 
factory method  of  assaying  is  obtained.  (See  Allen,  Com.  Org.  Anal., 
3d  ed.,  vol.  ii,  Part  ii,  p.  230.)  One  gramme  of  the  carefully  sampled 
specimen  is  placed  in  a  flask  holding  five  hundred  cubic  centimetres, 
forty-five  cubic  centimetres  of  the  very  strongest  glacial  acetic  acid  is 
added,  and  an  inverted  condenser,  or  long  glass  tube  adapted  to  the 
flask.  The  liquid  is  then  brought  to  the  boiling  point,  and,  while  boil- 
ing, the  chromic  acid  solution  is  added  to  it  gradually,  drop  by  drop,  by 
means  of  a  tapped  funnel  passing  through  the  india-rubber  stopper  in 


428   INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

the  flask,  or  inserted  in  the  top  of  the  vertical  condenser.  The  chromic 
acid  solution  is  prepared  by  dissolving  fifteen  grammes  of  crystallized 
chromic  anhydride  in  ten  cubic  centimetres  of  water  and  ten  of  glacial 
acetic  acid.  The  addition  of  the  oxidizing  agent  should  occupy  two 
hours,  and  the  contents  of  the  flask  should  be  kept  in  constant  ebullition 
for  two  hours  longer.  The  flask  is  then  left  for  twelve  hours,  when  the 
contents  should  be  diluted  with  four  hundred  cubic  centimetres  of  cold 
water,  and  allowed  to  rest  for  three  hours  longer.  The  precipitated 
anthraquinone  is  filtered  off,  and  well  washed  on  the  filter  with  cold 
water,  and  with  a  boiling  one  per  cent,  solution  of  caustic  soda  and 
again  with  water.  The  anthraquinone  is  rinsed  from  the  filter  into  a 
small  dish,  the  water  evaporated  off,  the  residue  dried  at  100°  C.,  and 
weighed.  The  following  after-treatment  is  now  universally  employed: 
to  the  weighed  residue  ten  times  its  weight  of  fuming  sulphuric  acid  is 
added,  and  the  whole  heated  to  100°  C.  on  a  water-bath  for  ten  minutes, 
after  which  it  is  left  in  a  damp  place  for  twelve  hours  to  absorb  water, 
when  two  hundred  cubic  centimetres  of  water  are  added;  the  precipi- 
tated anthraquinone  filtered  off,  washed  with  water,  and  then  with  one 
hundred  cubic  centimetres  of  a  one  per  cent,  boiling  solution  of  caustic 
soda,  and  finally  with  boiling  water,  transferred  to  a  dish,  any  water 
being  evaporated  off,  and  the  whole  dried  at  100°  C.  and  weighed.  The 
weight  of  the  anthraquinone  multiplied  by  the  factor,  .856,  gives  the 
real  anthracene  in  the  weight  of  the  sample. 

Anthracene  in  Tar  and  Pitch. — Nicol  (Z.  a.  Chemie,  xiv,  p.  318) 
treats  twenty  grammes  in  a  small  retort,  receiving  the  vapors  in  a  U 
tube  kept  at  200°  C.  The  more  volatile  products  do  not  condense,  but 
the  anthracene  and  other  hydrocarbons  do.  When  coking  has  taken 
place,  the  process  is  stopped,  and  the  neck  cut  off,  pounded,  and  the 
powder  added  to  the  distillate.  The  whole  is  then  dissolved  in  glacial 
acetic  acid  and  subjected  to  oxidation  with  chromic  acid  as  above  de- 
scribed. Watson  Smith  does  not  recommend  the  use  of  such  a  small 
quantity  (twenty  grammes)  ;  he  employs  a  similar  method  but  operates 
upon,  at  least,  a  litre,  rejecting  the  portion  distilling  just  before  the 
coking.  The  anthracene  oil  is  well  mixed  and  an  aliquot  part  employed. 

(/)  Pitch. — The  uses  to  which  this  residue  is  put  are  such  that  an 
elaborate  method  of  valuation  is  unnecessary,  although  the  method  for 
asphalt  is  applicable.  To  distinguish  between  the  two,  one  gramme  of 
the  sample  is  treated  with  five  cubic  centimetres  of  petroleum-spirit, 
and  rapidly  shaken.  The  mixture  is  filtered,  and  five  to  six  drops  of  the 
filtrate  diluted  to  five  cubic  centimetres  with  petroleum-spirit,  when  a 
greenish  fluorescence  will  be  noticed  in  the  case  of  tar.  Five  cubic  cen- 
timetres of  rectified  spirit  should  then  be  added,  the  mixture  shaken  and 
allowed  to  stand.  The  upper  layer  will  consist  of  strongly-colored  petro- 
leum-spirit, while  the  lower  layer  of  alcohol  will  have  a  golden-yellow 
color  if  coal-tar  is  present.  In  the  case  of  mineral  asphalt,  the  alcohol 
is  faintly  straw-yellow  and  often  colorless. 

3.  VALUATION  OF  AMMONIA-LIQUOR. — Ordinarily,  the  Twaddle  hydro- 
meter is  employed  to  determine  the  strength  of  ammonia-liquor;  every 
degree  of  the  instrument  is  taken  to  represent  such  an  amount  of 


DESTRUCTIVE  DISTILLATION  OF  COAL.  429 

ammonia  in  the  liquor  so  tested  that  one  gallon  will  require  two  ounces 
of  concentrated  oil  of  vitriol  to  saturate  it;  by  this  means  a  liquor  of  5° 
Tw.  would  be  known  as  "Ten-ounce,"  4°  Tw.  would  be  "Eight-ounce," 
etc.  These  results  are  fallacious,  owing  to  the  presence  of  substances 
which  cause  a  false  strength  to  be  indicated. 

The  most  accurate  and  practical  method  consists  in  decomposing  ten 
cubic  centimetres  of  the  gas-liquor  to  be  assayed  in  a  flask  by  means  of  a 
solution  of  caustic  soda,  applying  heat,  and  collecting  the  vapors  of 
ammonia  evolved  in  a  known  quantity  of  normal  sulphuric  acid  con- 
tained in  another  flask  suitably  connected ;  the  ammonia  vapors  neutralize 
part  of  this  acid,  and  that  which  remains  uncombined  is  exactly  neu- 
tralized in  the  presence  of  litmus  solution  with  normal  ammonia,  when 
the  percentage  of  ammonia  is  at  once  determined. 

4.  ANALYSIS  OP  ILLUMINATING  GAS. — The  analysis  of  illuminating 
gas  can  be  most  conveniently  carried  out  for  technical  purposes  with  the 
absorption  apparatus  devised  by  Hempel,  although  there  are  several 
other  forms  in  use  which  give  results  equally,  and  in  some  cases  more, 
accurate.  Hempel  employs,  for  measuring  the  gas  under  examination, 
a  cylindrical  tube,  similar  to  an  ordinary  burette,  graduated  to  one 
hundred  cubic  centimetres  in  one-fifths,  and  mounted  in  an  iron  base. 
This  burette  is  open  at  the  top,  and  at  the  bottom  by  means  of  a  side- 
tube.  Another  tube  similar  to  the  first,  but  without  graduations,  is  used 
as  a  "level-tube,"  and  is  connected  to  the  burette  by  a  caoutchouc  tube 
of  sufficient  length  that  the  level-tilbe  can  be  raised  to  the  height  of  the 
former  without  inconvenience.  There  are  also  used  pipettes,  the  ordi- 
nary form  of  which  consists  of  two  glass  bulbs,  connected  by  means  of 
capillary  tubes,  and  fastened  to  a  board  provided  with  openings  to 
accommodate  the  bulbs,  and  mounted  upon  a  foot.  From  one  of  the 
bulbs  a  siphon-shaped  tube  extends,  which  projects  a  short  distance 
beyond  the  stand,  and  to  which  is  attached  a  caoutchouc  tube  connect- 
ing it  with  the  top  of  the  burette.  The  pipettes  contain  the  several 
liquids  and  solid  reagents  necessary  to  absorb  the  f  constituents  of  the 
gas.  Besides  the  simple  form  above  mentioned,  there  is  a  "tubulated 
absorption  pipette,"  so  made  as  to  allow  the  introduction  of  solids,  and 
which  can  be  readily  altered  to  a  pipette  for  the  generation  and  reten- 
tion of  gases,  as  hydrogen  and  carbon  dioxide,  by  means  of  zinc  or 
calcite  respectively,  the  acid  required  for  the  liberation  of  the  gas  being 
contained  in  the  second  bulb. 

Another  form  is  the  "compound  absorption  pipette,"  which  is  em- 
ployed for  containing  the  reagents  readily  decomposed  upon  exposure 
to  the  atmosphere,  or  which  give  off  noxious  vapors. 

The  method  of  operating  is  as  follows:  The  level-tube,  previously 
filled  with  water,  is  raised  until  the  gas-burette  is  completely  filled,  when 
it  is  connected  by  means  of  a  caoutchouc  tube  to  the  "  aspirating-tube, " 
or  source  of  the  gas,  when  the  level-tube  is  lowered,  and  the  water  flows 
out,  causing  the  gas  to  take  its  place  in  the  burette ;  one  hundred  cubic 
centimetres  are  obtained,  which  is  noticed  by  causing  the  water-level  in 
each  tube  to  coincide  with  the  100-cubic-centimetre  mark  on  the  lower 
end  of  the  burette.  The  absorption  of  the  several  constituents  takes 


430  INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

place  on  connecting  the  top  of  the  burette  to  the  end  of  the  siphon- 
shaped  tube  before  mentioned,  when  the  level-tube  is  raised,  and  the  gas 
is  forced  from  the  burette  into  the  bulb  of  the  pipette,  the  absorbent  in 
which  has  been  forced  into  the  second  bulb.  When  all  the  gas  has  passed 
over,  compressors  are  applied  and  the  pipette  detached,  and  very  gently 
agitated  from  two  to  five  minutes,  in  which  time  the  absorption  will  be 
complete;  the  pipette  is  again  attached,  the  level-tube  lowered,  when  the 
remainder  of  the  gas  is  drawn  back  to  the  burette,  which  is  closed,  the 
water-level  in  each  brought  to  coincide,  and  the  reading  taken.  The 
difference  between  this  reading  and  the  original  volume  of  gas  taken  is 
the  volume  absorbed.  One  constituent  after  another  is  in  this  way  with- 
drawn by  using  pipettes  containing  solutions  having  affinity  for  the 
several  gas  components,  as  indicated  below: 

Carbon  dioxide  (COj).         Solution  of  potassium  hydroxide. 

Ethylene    (C2H4).       "I  Fuming  sulphuric  acid  or  bromine-water.     After  agita- 

Propylene    (C3H6).     I  tion,  the  vapors  remaining  in  the  gas  are  removed  by 

Butylene    (C4H8).       J  contact  with  potassium  hydroxide  solution. 

Benzene  vapor   (C6H6).        Fuming  nitric  acid  may  be  employed,   and  the  nitrous 

vapor  remaining  removed  by  agitation  in  the  potassium 

hydroxide  pipette,  or  absolute  alcohol  is  used. 
Oxygen   (O).  An  alkaline  solution  of  pyrogallol,  or  phosphorus  chips  in 

the  presence  of  water,  can  be  used. 
Carbon  monoxide  (CO).      A   solution  of  cuprous  chloride  in  hydrochloric  acid  or 

ammonia. 

Hydrogen   (H).          ^  Residue,    uabsorbed.      Constituents    determined    by    corn- 

Methane   (CH4).  bustion,  mixing  the  residual  gas  with  air,  and  passing 

Nitrogen    (N).  )  the  mixture  over  palladium  sponge. 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

1877. — Gasometrische  Methoden.  Robert  Bunsen,  2te  Auf.,  Braunschweig. 
1880. — Das  Anthracen  und  seine  Derivate,  G.  Auerbaeh,  2te  Auf.,  Braunschweig. 

Das  Holz  und  seine  Destillations-Producte,  Dr.  G.  Thenius,  Vienna. 
1883. — Die  Verwerthung  des  Holzes  auf  Chemischen  Wege,  J.  Bersch,  Vienna. 
1885. — Conservirung  des  Holzes,  C.  Heinzerling,  Braunschweig. 

Hand-book  of  Technical  Gas  Analysis,  O.  Winkler,  translated  by  G.  Lunge, 

London. 
1887. — Manufacture  of  Gas  from  Tar,  Oil,  etc.,  W.  Burns,  London  and  New  York. 

Die  technische  Verwerthung  des  Steinkohlentheers,  G.  Thenius,  Vienna. 

Die  chemische  Technologic  der  Brennstoffe,  F.  Fischer,  Braunschweig. 

1889 Traitement  des  Eaux  Ammoniacales,  etc.,  Weill-Goetz  et  Desor,  Paris. 

1890. — Ammonia  and  Ammonia  Compounds,  Arnold,  translated  by  Colman,  London. 

A  Practical  Treatise  on  the  Manufacture  of  Coal-Gas,  W.  Richards,  London. 

Dictionary  of  Applied  Chemistry,  T.  E.  Thorpe,  3  vols.,  London. 

L'Ammoniaque  dans  1'Industrie,  C.  Tellier,  Paris. 
1891. — Fabrikation  der  Leuchtgase,  G.  Thenius,  Leipzig. 

Die  Chemie  der  Steinkohlen,  F.  Muck,  2te  Auf.,  Leipzig. 

The  Chemistry  of  Illuminating  Gas,  Humphreys,  London. 

Carbolsaiire  und  Carbolsaiire  Praeparate,  H.  Kb'hler,  Berlin. 
1892. — Methods  of  Gas  Analysis,  W.  Hempel,  translated  by  L.  M.  Dennis,  New  York. 

Fuels,  Solid,  Liquid,  and  Gaseous,  Phillips,  London. 

Destructive  Distillation,  Edmund  J.  Mills,  4th  ed.,  London. 

Gas-works,  their  Construction,  etc.,  Hughes  and  Richards,  London. 


BIBLIOGRAPHY  AND  STATISTICS. 


431 


1894. — Das  Conserviren  des  Holzes,  Louis  E.  Andrds,  Wien. 

1895. — A  Treatise  on  the  Manufacture  of  Coke,  etc.,  John  Fulton,  Scranton,  Pa. 

1896. — Le  distillation  des  Bois,  E.  Barillot,  Paris. 

The  Chemistry  of  Gas  Manufacture,  W.  J.  Butterfield,  Philadelphia. 

1899. — The  Chemistry  of  Coke,  from  the  German  of  0.  Simmersbach,  W.  C.  An- 
derson, Glasgow. 

1900. — Coal-tar  and  Ammonia,  by  George  Lunge,  3d  ed.,  2  vols.,  London. 

1901. — Die  Chemie  des   Steinkohlentheers,   Dr.   Gustav   Schultz,   3te  Auf.,  2   Bde., 
Braunschweig. 

1907. — Utilization  of  Wood-waste  by  Distillation,  W.  B.  Harper,  St.  Louis. 

1908. — Wood    Products,    Distillates,    and    Extracts,    translated    by    Donald    Grant, 
London. 

1909. — Technologie  der  Holzverkohlung,  M.  Klar,  2te  Auf.,  J.  Springer,  Berlin. 

STATISTICS. 

1.  WOOD  DISTILLATION  IN  THE  UNITED  STATES. — 

Hard  woods.  Soft  woods.  Total. 

1907.  Cords   of   wood    distilled 1,219,771           62,349  1,282,120 

1908.  Cords   of  wood   distilled 878,632           99,212  977,844 

1909.  Cords   of   wood    distilled 1,149,847  115,310  1,265,157 

1910.  Cords   of   wood   distilled 1,257,997  192,442  1,450,439 

Of  the  147  plants  in  operation  in  1910,  117  were  engaged  in  the 
distillation  of  hard  woods,  and  30  in  the  distillation  of  soft  woods. 

2.  PRODUCTION  OF  COKE  IN  THE  UNITED  STATES  (IN  TONS  OF  2000 
POUNDS). — 

1909.  1910. 

Total    production     35,076,902  36,228,773 

Valued    at     $81,638,058  $82,714,095 

Of   which    Pennsylvania    produced    23,098,483  22,875,000 

Valued    at     $46,196,966  $45,978,750 

3.  PRODUCTION  OF  COKE,  ETC.,  IN  BY-PRODUCT  OVENS  (IN  TONS  OF  2000 

POUNDS). — 

1909.  1910. 

Number  of  by-product  ovens 3,914  4,078 

Coke    produced    in    tons 6,254,644  7,138,734 

Value  of   coke   produced $21,703,462  $24,793,016 

Value    of    by-products 8,073.948  8,479,517 

These  by-products  in  1910  consisted  of  : — 

27,692,858  cubic  feet  of  surplus  gas,  valued  at $3,017,908 

66,303,214  gallons  of  tar,  valued  at 1,599,453 

70,247,543  pounds  of  sulphate  of  ammonia,  valued  at 1,841,062 

20,229,421  pounds  of  anhydrous  ammonia,  valued  at 1,725,266 

4,654,282  gallons  of  ammoniacal  liquor,  valued  at 295,868 

Total     $8,479,557 

England  produces  the  largest  quantity  of  coal  tar  of  any  country  in 
the  world,  the  production  in  1901  having  been  908,000  tons.*  The  total 
world's  production  has  been  estimated  at  3,000,000  tons. 

*  G.  Miiller,  Die  chem.  Industrie,  Leipzig,  1909,  p.  334. 


432  INDUSTRIES  BASED  UPON  DESTRUCTIVE  DISTILLATION. 

G.  Lunge,*  from  information  gathered  by  himself,  puts  the  pro- 
duction of  coal-tar  for  1886  in  Holland  at  20,000  to  22,000  tons,  in 
Belgium  at  about  30,000  tons,  and  in  the  United  States  at  120,000  tons, 
of  which  some  60,000  tons  are  distilled,  37,000  tons  are  employed  for 
manufacturing  roofing-paper,  roof-coating,  etc.,  and  some  23,000  tons 
are  used  up  in  the  raw  state. 

4.  OF  COAL-TAR  DISTILLATION  PRODUCTS. — The  estimate  of  Mr.  Wil- 
ton of  the  coal-tar  production  of  the  United  Kingdom  for  1885,  which 
was  643,000  tons,  includes  the  following  additional  details: 

Ammoniacal  liquor  from  tar  alone. .   3,600,000  gallons  =  1200  tons  of  sulphate. 

Carbolic    acid    (crude)     6.00,000       " 

Creosote    oil    21,600,000       " 

Of  this,  there  was  liquid  creosote.  10,800,000       " 

Of  this,  there  were  creosote  salts 

( crude  naphthalene,  etc. ) 56,620  tons. 

Corresponding    to    pure    naphtha- 
lene          25,620  " 

Green  oil  20,400,000  gallons. 

Benzol  and  toluol 1,500,000       " 

Solvent   naphtha    620,000       " 

Anthracene  (pure)    3,420  tons. 

Pitch 396,000     " 

5.  PRODUCTION  OF  SULPHATE  OF  AMMONIA. — a.  World's  Sulphate  of 
Ammonia  Production.     (In  metric  tons  of  2204.6  pounds.) 

1905.               1906.                1907.                1908.                1909.  1910. 

England    273,550  294,170  318,400  330,450  354,747  374,925 

Germany    190,000  235,000  287,000  313,000  330,000  373,000 

United  States   59,250  68,000         90,120         79,500  96,600  105,143 

France    47,300  49,100         52,700         52,600  53,600  56,000 

Belgium    and    Holland..   24,200  30,000         55,000  35,000  40,000  43,000 

Spain    10,000         10,000         12,000           12,000  9.000 

Italy     4,500           5,000         11,000  80,000  12,000  12,000 

Other  countries    40,500  40,000         65,000          73,000  79,000 


694,300       731,270       891,200       890,550  971,947    1,052,068 

b.  Ammonium  Sulphate  and  Sulphate  Equivalent  Produced  in  the 
United  Kingdom.     (In  tons  of  2240  pounds.) 

1905.                   1906.                  1907.                  1908.  1909.                   1910. 

Gas  works   155,957         107,160         165,474         165,218  164,276         167,820 

Ironworks    20,376           21,284           21,024           18,131  20,228           20,139 

Shale   works    46,344           48,534           51,338           53,628  57,048           59,113 

Coke  ovens    30,732           43,677           53,572           64,227  82,886           92,655 

Producer    gas    and 

carbonizingworks  15,705           18,736           21,873           24,024  24,705           27,850 

c.  United  States  Ammonia  Production,  Expressed  in  Sulphate  Equiv- 
alent.    (In  tons  of  2000  pounds.) 


1905     65,296 

1906     75,000 

1907     99,309 


1908 83,400 

1909 106,500 

1910 116,000 


Lunge,  Coal-Tar  and  Ammonia,  2d  ed.,  p.   15. 


RAW  MATERIALS.  433 


CHAPTER    XII. 

THE  ARTIFICIAL   COLORING   MATTERS. 

I.  Raw  Materials. 

1.  HYDROCARBONS. — Benzene  Series. — In  the  manufacture  of  the  arti- 
ficial coloring  matters,  the  hydrocarbons  which  find  application  as  raw 
materials  are  limited  mainly  to  benzene,  naphthalene,  and  anthracene, 
their  homologues  and  derivatives;  of  which,  probably,  benzene  is  the 
most  important. 

The  benezene  series  is  as  follows: 

Boiling-point.  Specific  gravity. 

Benzene,  C8H8 80.4°  C.  .884  at  15°  C. 

Toluene,  C6H5.CH3 110°  C.  .869  at  15°  C. 

(    o-Xylene 142°  C.  .893  at     0°  C. 

1  ™  Y^I™,.                                            IQQO  c.  .881  at     0°  C. 


1 


p-Xylene 138°  C.  .880  at     0°  C. 

Pseudocumene,  •>  (    169.5°  C.         .895  at     0°  C. 

Mesitylene,         J  ^Hj-CCHj), j    165<>  c  865  at  14o  c 

Durene,  C6H2.(CH3)4.      (Fuses  at  79°-80°  C.) 192°  C.  

Pentamethylbenzene,  C8H.(CHS)5.   (Fuses  at  5.5°  C.)..    231°  C 

Hexamethylbenzene,  C8(C'H3)8.   (Fuses  at  166°  C.) 265°  C.  

Of  which  only  the  first  three  are  employed  to  any  extent. 

Benzene  has  been  described  in  a  previous  chapter  (see  Tar  Distilla- 
tion), but  for  the  manufacture  of  colors  an  explanation  is  necessary; 
the  name  benzene,  chemically  speaking,  does  not  refer  to  the  light  frac- 
tions obtained  from  petroleum,  but  applies  solely  to  the  substance  dis- 
tilled from  coal-tar;  boiling  at  80.4°  to  81°  C.,  having  a  specific  gravity 
of  .899°  at  0°,  with  the  definite  composition  C6H6.  The  term  benzol,  on 
the  other  hand,  is  not  given  to  a  definite  compound,  but  to  a  mixture  of 
benzene  with  variable  quantities  of  toluene  and  xylene,  with  the  other 
homologous  of  the  same  series.  The  quantity  of  these  homologous  bodies 
contained  has  an  influence  upon  the  use  to  which  the  aniline  oil  obtained 
(by  subsequent  treatment  of  the  benzol)  can  be  put. 

The  pure  benzene,  free  from  the  high-boiling  homologues,  is  succes- 
sively converted  through  several  processes  to  dimethylaniline,  which  is 
the  base  of  the  valuable  methyl-violets.  For  the  fuchsine  process,  ben- 
zol, seventy-five  per  cent,  of  which  distils  between  80°  and  100°  C.  (con- 
taining toluene),  is  employed,  producing  aniline,  seventy-five  per  cent, 
of  which  distils  between  180°  and  190°  C.  High-boiling 'benzol,  115°  to 
120°  C.,  yields  aniline,  which  is  the  starting-point  for  the  production  of 
the  beautiful  series  of  xylidine  scarlets;  the  introduction,  however,  of 
pure  xylene  has  served  to  displace  the  above.  Allen  states  (Commercial 
Organic  Analysis,  2d  edv  vol.  ii,  p.  489),  "Ninety  per  cent,  benzol  is  a 

28 


434 


THE  ARTIFICIAL  COLORING  MATTERS. 


product  of  which  ninety  per  cent,  by  volume  distils  before  the  ther- 
mometer rises  above  100°  C.  A  good  sample  should  not  begin  to  distil 
under  80°  C.,  and  should  not  yield  more  than  twenty  to  thirty  per 
cent,  at  85°,  or  much  more  than  ninety  per  cent,  at  100°  C.  It  should 
wholly  distil  below  120°  C.  An  excessive  distillate — e.g.,  thirty-five  to 
forty  per  cent,  at  85°  C. — indicates  a  larger  proportion  of  carbon  disul- 
phide  or  light  hydrocarbons  than  is  desirable. 

"The  actual  percentage  composition  of  a  ninety  per  cent,  benzol  of 
good  quality  is  about  seventy  of  benzene,  twenty-four  of  toluene,  in- 
cluding a  little  xylene,  and  four  to  six  of  carbon  disulphide  and  light 
hydrocarbons.  The  proportion  of  real  benzene  may  fall  as  low  as  sixty 
or  rise  as  high  as  seventy-five  per  cent.  Ninety  per  cent,  benzol  should 
be  colorless  and  free  from  opalescence. " 

"Fifty  per  cent,  'benzol,  often  called  50/90  benzol,  is  a  product  of 
which  fifty  per  cent,  by  volume  distils  over  at  a  temperature  not  exceed- 
ing 100°  C.,  and  forty  per  cent,  more  below  120°.  It  should  wholly 
distil  below  130°." 

' '  Thirty  per  cent,  benzol  is  a  product  of  which  thirty  per  cent,  distils 
below  100°,  about  sixty  per  cent,  more  passing  over  between  100°  and 
120°.  It  consists  chiefly  of  toluene  and  xylene,  with  small  proportions 
of  benzene,  cumene,  etc." 

The  following  table  from  Schultz  (Steinkohlentheers)  indicates  the 
general  properties  of  the  three  commercial  benzols  above  described  when 
subjected  to  distillation: 


Thirty 
per  cent. 

Fifty 
per  cent. 

Ninety 
per  cent. 

To    85°  

0 

0 

25 

90°  

2 

4 

70 

95°  

12 

26 

83 

100°  

30 

50 

90 

105°  

42 

62 

94 

110°  

70 

71 

97 

116°  

82 

82 

98 

120°  

90 

90 

99 

The  theoretical  quantities  of  commercially  applicable  products  from 
benzol  are: 

For  100  parts,  157.6  parts  nitrobenzol. 

"       "         "  119.2       "      aniline. 

"       "         "  215.3       "      dinitrobenzol. 

"       "         "  155.1       "      dimethylaniline. 

"         "  191.0       "      diethylaiiiline. 

Toluene,  or  Methylbenzene,  C6H5.CH3,  is  obtained  by  careful  distilla- 
tion of  coal-tar  benzols,  and  can  be  obtained  from  the  balsam  of  tolu 
and  other  sources.  It  is  quite  similar  in  its  properties  to  benzene; 
fluid  at  ordinary  temperatures,  and  when  pure  boils  between  110°  and 
111°  C.  Specific  gravity  .869.  It  is  employed  for  the  production  of 


RAW  MATERIALS. 


435 


nitrotoluene,  toluidine,  benzylchloride,  benzalchloride,  and  benzalde- 
hyde, — the  base  of  a  valuable  series  of  green  colors.  The  theoretical 
yield  of  commercial  products  from  toluene  is  as  follows: 

For  100  parts,  148.9  parts  nitrotoluene. 
'   "       "        "        116.3       "      toluidine 
"       "         "        115.3       «      benzaldehyde. 

Xylene,  or  Dimethylbenzene,  C6H4.  (CH3)2,  exists  under  similar  con- 
ditions to  tqluene,  and  is  found  in  coal-tar.  There  are  three  xylenes, 
the  ortho-,  meta-,  and  para-,  the  second  being  most  abundantly  obtained. 
Owing  to  the  slight  difference  between  their  respective  boiling-points, 
a  commercial  separation  by  distillation  is  practically  impossible. 

The  annexed  table  gives  the  nature  and  behavior  of  the  three  iso- 
meric  hydrocarbons  mentioned. 


Ortho-xylene. 

Meta-xylene. 

Para-xylene. 

Melting  point     

Fluid. 

Fluid. 

15°  C 

Boiling-point      

141°  to  142°  C. 

139°  C. 

137  5°  to  138°  C 

Specific  gravity      .... 

.8668  at  19°  C. 

8621  at  19  5°  C 

r^        f  Dilute  nitric  acid 

v 
•26    1 

S'S    i 
x  ^    \   Permanganate 

^        [  Chromic  acid   .    . 
Sulphuric  acid  (66°  Be.) 
Sulphuric  acid   (fuming) 
Melting  point  of  the  sul- 
phochloride    

o-Toluic  acid, 
melting  point 
102°  C. 
Phthalic  acid. 
Decomposed. 
Sulphonic  acid. 
Sulphonic  acid. 

62°  C. 

w-Toluic  acid,   melt- 
ing point  160°  C. 

i  Isophthalic  acid. 

Two  sulphonic  acids. 
Two  sulphonic  acids. 

(a)  34°  C  ,  (b)  liquid 

p-To\u\c  acid, 
melting  point 
178°  C. 

Terephthalic  acid 

No  change. 
Sulphonic  acid. 

26°  C 

Melting  point  of  the  sul- 
phamide      

144°  C 

(a)  137°  C     (6)  96°  C 

148°  C 

From  Schultz,  "  Steinkohlentheers." 

Naphthalene  Series. — Naphthalene,  C10H8,  as  a  raw  material,  enters 
largely  into  the  production  of  the  extensive  series  of  azo-coloring  mat- 
ters, and  for  such  use  it  is  converted  into  intermediary  products,  of 
which  the  alpha-  and  beta-naphthols  are  the  most  familiar.  The  occur- 
rence, properties,  and  production  of  naphthalene  are  referred  to  on 
page  419. 

Methyl-naphthalene,  C10H7CH3. — Two  isomers  exist  in  coal-tar,  and 
can  be  separated  from  that  fraction  of  the  distillate  boiling  at  from 
220°  to  270°  C.  The  first  of  these  is  a  liquid  boiling  at  243°  C. ;  specific 
gravity  1.0287  at  11.5°.  The  second  is  a  solid,  looking  like  naphthalene, 
melting  at  32.5°  C.  and  boiling  at  242°  C. 

Ethyl-naphthalene,  C12H12. — Two  isomers,  a-  and  /?-,  are  known. 
a-Ethyl-naphthalene,  produced  from  a-brom-naphthalene  and  ethyl- 
bromide,  and  distilled  in  vacuum,  boils  a.t  from  257°  to  259.5°  C. 
iS-Ethyl-naphthalene,  from  /?-brom-naphthalene,  ethyl  bromide,  and 
sodium,  boils  at  from  250°  to  251°  C. 

Diphenyl,  C12H10,  has  been  found  in  coal-tar,  and  is  readily  obtained 
when  benzene  vapors  are  passed  through  a  red-hot  tube.  It  is  insoluble 


436  THE  ARTIFICIAL  COLORING  MATTERS. 

in  water,  soluble  in  hot  alcohol  and  in  ether.  It  forms  large  colorless 
scales,  melting  at  71°  C.  and  boiling  at  254°  C.  Oxidized  by  chromic 
acid,  it  yields  benzoic  acid. 

Stilbene,  C14H12. — This  compound,  which  is  diphenylethylene 
(C6H3.CH  =  CH.C6H5),  is  formed  when  toluene  or  dibenzyl  is  led  over 
heated  lead  oxide.  It  crystallizes  in  colorless  scales,  melting  at  125°  C. 
Forms  the  basis  of  numerous  important  dyes. 

Anthracene  Series. — Anthracene,  C14H10,  reference  to  which  has  been 
made  in  the  previous  chapter,  is  employed  for  the  production  of  ali- 
zarine and  allied  bodies,  the  successful  introduction  of  which  caused  a 
revolution  in  the  processes  of  dyeing,  and  made  useless  for  the  time 
great  areas  of  land  which  were  devoted  to  the  culture  of  madder.  An- 
thracene, as  it  occurs  in  commerce,  is  rarely  pure,  being  made  up  of  a 
very  large  number  of  hydrocarbons,  several  of  which  have  not  been 
investigated.  The  following  may  be  mentioned: 

Methyl-anthracene,  C15H12,  closely  resembles  anthracene.  It  differs 
from  that  body  in  having  a  methyl  group  substituted  for  an  H  atom 
of  one  of  the  benzene  rings.  It  occurs  in  coal-tar  in  small  quantity,  and 
owing  to  the  high  boiling-point,  over  360°  C.,  it  is  found  in  the  anthra- 
cene. Crystallizes  in  pale-yellow  leaflets,  melting  at  199°  to  200°. 

Phenyl-anthracene,  C20H14,  is  formed  when  phenyl-anthranol  or 
coerulem  is  heated  with  zinc-dust.  Slightly  soluble  in  hot  alcohol,  ether, 
benzene,  carbon  disulphide,  and  chloroform,  and,  upon  cooling,  crys- 
tallizes from  the  above  solvents  in  yellow  plates,  melting  at  152°  to  153° 
C.  The  solutions  have  a  blue  fluorescence. 

Fluorene,  or  Diphenylen-methane,  C13H10,  is  found  in  coal-tar,  and 
can  be  obtained  by  passing  diphenylmethane  through  a  combustion-tube 
heated  to  redness ;  it  can  also  be  obtained  by  distilling  diphenyleneketone 
over  heated  zinc-dust,  or  by  heating  the  same  substance  with  hydriodic 
acid  and  phosphorus  from  150°  to  160°.  Very  soluble  in  hot  alcohol, 
less  in  cold;  crystallizes  in  colorless  plates  having  a  violet  fluorescence. 
Melts  at  113°  C.,  boils  at  295°  C. 

Phenanthrene,  C14H10. — This  hydrocarbon  is  isomeric  with  anthra- 
cene, is  found  with  it,  and  forms  a  large  part  of,  the  last  fraction  of 
coal-tar.  Compared  with  anthracene,  the  melting  point  is  considerably 
lower,  while  the  boiling-points  are  somewhat  closer.  It  is  much  more 
soluble  in  alcohol,  by  which  means  a  separation  is  effected ;  the  low  melt- 
ing point  materially  assisting.  Crystallizes  in  colorless,  shining  plates, 
melting  at  100°  and  boiling  at  340°,  insoluble  in  water,  but  soluble  in 
fifty  parts  of  alcohol  in  the  cold,  and  in  ten  parts  on  boiling;  easily 
soluble  in  ether  and  benzene.  It  imparts  a  blue  fluorescence  when  dis- 
solved. When  oxidized,  phenanthrenquinone  is  formed.  Technically, 
but  little  use  is  made  of  it,  being  chiefly  employed  in  the  oil  baths  for 
alkali  melts,  heating  autoclaves,  subliming  phthalic  anhydride,  etc. 

Fluoranthene,  C15H10,  occurs  in  the  highest  boiling  tar  fractions; 
crystallizes  in  needles;  melts  at  109°. 

Pseudophenanthrene,  C16H12,  is  found  in  crude  anthracene,  and  crys- 
tallizes in  large  glistening  plates,  which  melt  at  115°.  Pyrene,  C16H10, 


RAW  MATERIALS. 


437 


Retene,  C18H18,  Chrysene,  C18H12,  and  Picene,  C22H14,  are  bodies  which 
occur  in  the  highest  fractions  with  fiuoranthene,  and  cannot  be  classed 
as  raw  materials, — no  technical  importance  being  attached  to  them. 

2.  HALOGEN  DERIVATIVES. — From  Benzene. — The  following  table  of 
the  halogen  derivatives  of  benzene  indicates  those  whose  constitution  is 
known.  They  are  produced  by  the  action  of  the  halogens  upon  the 
hydrocarbons  directly,  or  through  the  action  of  the  halogen  compounds 
of  phosphorus  upon  phenols  and  aromatic  alcohols.  Two  classes  are 
produced,  substitution  and  addition  compounds.  The  former  occur 
under  ordinary  conditions,  while  the  latter  are  formed  when  the  reaction 
takes  place  in  direct  sunlight.  Of  the  two,  the  substitution  products  are 
the  more  stable,  the  addition  products  being  easily  decomposed. 

The  following  table  gives  the  formulas  of  the  several  halogen  deriva- 
tives of  benzene  and  the  boiling-points  of  the  more  important  of  the 
several  isomeric  compounds: 


Halogen  substitution  products  of  benzene. 

C6H6 

C.H, 
C6H< 
CeH, 
C6H2 

cX 

C6 

Cl 

C12 
CL 
Cl 

01, 

C16 

133° 
179° 
213° 

246° 
276° 
332° 

Br 

£ 

f 

Br6 

154° 
224° 
276° 
329° 

219° 
278° 

219° 

J! 

185° 

277° 

285° 

172° 
208° 
246° 

173° 
218° 
254° 

} 

From  Toluene. —  (1)  Benzyl-chloride  (Chlorbenzyl} ,  C6H5CH2.C1, 
results  from  the  action  of  hydrochloric  acid  upon  benzyl  alcohol 
(C6H0.CH2.OH),  or  by  acting  on  boiling  toluene  with  chlorine,  this 
method  being  the  one  most  generally  used;  the  product  is  washed  with 
water  containing  a  little  alkali,  when  it  is  freed  from  impurities  by  dis- 
tillation. It  is  a  colorless  fluid,  specific  gravity  1.113,  boils  at  179°, 
insoluble  in  water,  but  soluble  in  alcohol  and  ether,  and  possesses  an 
exceedingly  penetrating  odor,  acting  upon  the  eyes  and  mucous  mem- 
brane of  the  nose.  Technically,  it  finds  considerable  application  in  the 
color  industry. 

(2)  Benzol-chloride,     CeHg.CH.Cl^. — Formed     when     chlorine     acts 
upon  boiling  benzyl-chloride,   or  when  phosphorus  penta-chloride  acts 
upon  benzaldehyde.     It  is  a.  colorless  liquid,  having  ordinarily  but  little 
odor,  but  upon  the  application  of  heat  gives  off  a  vapor  producing  effects 
similar  to  the  preceding.     Boils  at  206°  to  207° ;  specific  gravity  at  16° 
1.295. 

(3)  Benzo-trichloride,  C0H5.C.C13,  is  obtained  by  acting  with  chlorine 
upon  boiling  toluene  until  no  further  increase  in  weight  takes  place, 
when  it  is  washed  in  water  containing  alkali,  dried,  and  distilled  in  a 
vacuum.     Boils  at  213°  to  214°  ;  specific  gravity  1.38  at  14°.     It  has  a 
penetrating  odor,  and  is  highly  refractive. 

Bromine  Derivatives  of  Xylene. — These  are  obtained  when  bromine 
is  allowed  to  act  upon  the  hydrocarbon  or  its  isomers,  or  upon  bromi- 


438  THE  ARTIFICIAL  COLORING  MATTERS. 

nated  compounds  of  the  same,  with  or  without  the  presence  of  iodine. 
They  find  no  application  industrially. 

Halogen  Derivatives  of  Naphthalene. — (1)  Naphthalene  Dichloride, 
C10H8C12,  is  a  liquid,  easily  decomposed;  produced  as  an  addition  com- 
pound by  the  action  of  chlorine  gas  upon  naphthalene. 

(2)  Naphthalene  Tetrachloride,  C10H8C14. — This  substance  is  manu- 
factured in  large  quantities  by  passing  chlorine  gas  through  the  melted 
hydrocarbon  in  a  suitable  apparatus,  or  by  grinding  the  naphthalene 
to  a  paste  with  water  and  intimately  kneading  therein  sodium  or  potas- 
sium chlorate,  moulding  into  balls,  and  drying,  after  which  they  are 
immersed  in  concentrated  hydrochloric  acid.    It  crystallizes  from  chloro- 
form in  large  rhombohedra,  melting  at  182°,   and  when  boiled  with 
nitric  acid  is  converted  into  phthalic  acid,  which  is  the  chief  product 
obtained  from  it. 

(3)  a-Brom-naphthalene,   C10H7.Br. — Formed  by  the   direct  bromi- 
nation  of  the  hydrocarbon,  or  by  the  substitution  of  bromine  for  the 
ami  do  group  in  a  brom-a-naphthylamine.    It  is  a  liquid,  boiling  at  277°  ; 
specific  gravity  1.503  at  12°.    Insoluble  in  water,  soluble  in  acohol  and 
ether. 

(4)  (3-Naphthyl-chloride,  C10H7.CH2C1,  is  formed  when  chlorine  acts 
upon  /?-methyl-naphthalene  at  a  temperature  of  240°  to  250°.    Melts  at 
47°,  boils  at  168°. 

(5)  fS-Naphthyl-jbromide,  C10H7.CH2Br. — Formed  when  the  vapor  of 
bromine  with  C02  gas  is  brought  in  contact  with  ^-methyl-naphtha- 
lene, heated  to  240°.     Crystallizes  from  alcohol  in  white  plates,  which 
melt  at  56°. 

Anthracene  Derivatives. —  (1)  Monochlor-anthracene,  C14H0.C1. — 
When  dichlor-anthracene  is  heated,  hydrochloric  acid  is  evolved,  having 
the  monochlor  derivative.  Soluble  in  alcohol,  ether,  carbon  disulphide, 
and  benzene.  Crystallizes  in  yellow  needles,  melting  at  103°. 

(2)  Dichlor-anthracene,  C14H8.C12,  is  produced  when  anthracene  is 
allowed  to  remain  in  contact  with  chlorine,  or  when  the  monochlor  deri- 
vative is  similarly  treated,  being  maintained  at  a  temperature  of  100°. 
Freely  soluble  in  benzene,  but  not  readily  in  alcohol  or  ether.     Forms 
beautiful  yellow  lustrous  needles,  which  melt  at  209°.     Treated  with 
sulphuric  acid  at  a  low  temperature,  dichlor-anthracene-sulphonic  acid 
occurs  in  solution ;  this,  when  heated,  yields  sulphurous  acid,  hydro- 
chloric acid,  and  the  anthraquinone-disulphonic  acid,  which  is  the  imme- 
diate base  of  the  artificial  alizarine. 

(3)  Dibrom-anthracene,  C14H8Br2. — Upon  agitating  bromine  with  a 
solution  of  anthracene  in  carbon  disulphide,  this  derivative  is  formed. 
Difficultly  soluble  in  alcohol,  ether,  and  benzene;  hot  toluene  or  xylene 
answer  best.     Crystallizes  in  gold-yellow  needles,  melting  at  221°,  and 
subliming  without  decomposition. 

3.  NITRO-  DERIVATIVES. — By  the  action  of  nitric  acid  upon  the  hy- 
drocarbons nitro-  derivatives  are  obtained,  and  one  of  the  most  important 
of  these — nitrobenzene — is  manufactured  in  very  large  quantities  for 
use  in  the  color  industry. 


RAW  MATERIALS.  439 

(1)  Nitrobenzene,  C6H5.N02,  was  discovered  by  Mitscherlich,  who 
obtained  it  by  heating  benzene  or  benzoic  acid  with  fuming  nitric  acid. 
It  was  first  brought  into  trade,  bearing  the  name  "oil  of  mirbane" 
(artificial  oil  of  bitter  almonds),  by  Collas,  and  in  1847  a  patent  for  its 
manufacture  from  coal-tar  was  granted  to  Mansfield.     It  is  obtained  by 
adding  a  cooled  mixture  of  concentrated  sulphuric  acid  and  nitric  acid 
(150:  100)  to  the  hydrocarbon  and  agitating,  taking  care  that  the  tem- 
perature does  not  go  above  50°  C.     After  the  addition  of  the  acid  is 
complete,  heat  is  applied,  and  it  is  again  agitated.     The  oily  layer  is 
removed,  washed  with  dilute  alkali,  dried,  and  distilled.     Nitrobenzene, 
when  pure,  is  a  pale-yellow  fluid,  strongly  refractive,  having  the  odor 
of  bitter  almonds,  and  a  sweet,  though  burning,  taste.     Specific  gravity 
1.208  at  15°;  boils  at  206°  to  207°,  and  when  the  temperature  is  re- 
duced it  crystallizes  in  large  needles,  which  melt  at-}- 3°.     Nearly  in- 
soluble in  water,  though  with  alcohol,  ether,  and  benzene  it  is  readily 
soluble.     It  is  exceedingly  stable,  and  even  at  a  boiling  temperature  it 
is  not  acted  upon  by  either  bromine  or  chlorine.     It  is  poisonous,  and, 
according  to  Roscoe  and  Schorlemmer  (vol.  iii,  pt.  iii),  "especially  when 
the  vapor  is  inhaled;  it  produces  a  burning  sensation  in  the  mouth, 
nausea  and  giddiness,  also  cyanosis  of  the  lips  and  face,  and  in  serious 
cases,  which  frequently  end  fatally,  symptoms  of  a  general  depression." 

(2)  Dinitrobenzene,  C6H4(N02)2. — Three  isomers  of  this  derivative 
exist,  being  obtained  when  benzene  is  nitrated  with  the  concentrated 
acids,  as  in  the  preceding  case,  but  instead  of  being  cooled  is  boiled  for 
4  short  time,  when  the  product  is  washed  with  water,  pressed,  dissolved 
in  alcohol,  from  which  the  meta-nitro  body  crystallizes,  followed  upon 
standing  by  the  paranitro  compound.     Upon  distilling  the  alcohol  re- 
maining in  the  mother-liquors  from  the  para-  compound,  a  further  yield 
of  the  meta-  body  is  obtained,  finally  the  ortho-dinitrobenzene,  which 
occurs  in  small  quantity,  crystallizes,  and  is  purified  by  treatment  with 
acetic  acid,  from  which  it  is  deposited  in  needles,  having  a  melting  point 
of  117.9°.     The  para-  compound  occurs  in  monoclinic  needles,  melting 
at  172°,  and  subliming.    The  meta-  compound  finds  technical  application 
in  the  production  of  chrysoidine  and  Bismarck  brown,  and  is  manufac- 
tured on  a  large  scale  by  adding  a  mixture  of  one  hundred  kilos,  nitric 
acid   (specific  gravity  1.38)    and  one  hundred  and  fifty-six  kilos,  sul- 
phuric acid   (specific  gravity  1.84)   to  one  hundred  kilos,  of  benzene. 
When  the  reaction  is  over,  a  separation  of  the  acids  (which  can  be  used 
again)   from  the  product  occurs;  commercially,  the  product  is  washed 
with  warm  and  cold  water,  further  purification  being  unnecessary.     It 
crystallizes  in  needles  or  rhombic  tables,  which  melt  at  98.8°,  boiling  at 
297°.     Difficultly  soluble  in  warm  water,  easily  in  ether  and  alcohol. 

Nitrotoluene. — (1)  Nitrotoluene,  C6H4(N02)CH3,  occurs  in  three 
isomers.  The  ortho-  derivative  is  a  liquid  boiling  at  223°,  and  at  23.5° 
has  a  specific  gravity  of  1.162.  Does  not  become  solid  at  20°.  The 
meta-  derivative  melts  at  16°,  boils  at  230°  to  231°.  Specific  gravity  at 
22°  1.168.  Para-  nitrotoluene,  melting  point  54°,  distilling  unchanged 
at  236°,  occurs  in  colorless  prisms.  Nitrotoluene,  consisting  more  or 


440  THE  ARTIFICIAL  COLORING  MATTERS. 

less  of  a  mixture  of  the  three,  is  manufactured  in  large  quantities  and 
in  the  same  manner  as  nitrobenzene.  Ten  parts  of  toluene  are  mixed, 
and  continually  agitated  with  eleven  parts  of  nitric  acid  (specific 
gravity  1.22)  and  one  part  sulphuric  acid  (specific  gravity  1.33).  The 
product  is  treated  with  water,  and  afterwards  with  caustic  alkali;  dis- 
tilled to  remove  uncombined  toluene,  and  finally  distilled  with  super- 
heated steam.  When  fractionated,  that  part  passing  over  at  230°  yields, 
when  purified,  para-nitrotoluene,  and  is  employed  in  the  production  of 
toluidine,  tolidine,  and  fuchsine.  The  fraction  between  220°  and  223° 
is  nearly  all  ortho-nitrotoluene. 

(2)  Dinitrotoluenes,  C6H3(N02)2-CH3 — a-  or  ordinary  dinitrotoluene 
is  produced  when  toluene  is  added  to  a  mixture  of  fuming  nitric  and 
sulphuric  acids  and  boiled;  ortho-nitrotoluene  is  employed  for  the  man- 
ufacture also.  Crystallizes  in  needles,  which  melt  at  70.5° ;  insoluble  in 
water,  little  soluble  in  alcohol,  ether,  or  carbon  disulphide.  /2-dinitro- 
toluene,  isomeric  with  the  above,  is  produced  under  similar  conditions; 
or  it  can  be  made  by  replacing  the  amido  group  of  dinitroparatoluidine 
with  hydrogen.  Crystallizes  in  golden-yellow  needles;  melting 
point  61.5°. 

Trinitrotoluene,  CeH2.(N02)3CH3. — Produced  by  the  action  of  nitric 
and  sulphuric  acids  upon  toluene,  or  dinotrotoluene,  and  heating 
for  several  days.  a-Trinitrotoluene  is  soluble  in  alcohol,  crystallizing 
from  it  in  beautiful  needles,  which  melt  at  82°.  /^-Trinitrotoluene  crys- 
tallizes from  acetone  in  transparent  prisms,  which  melt  at  112°,  while 
from  alcohol  it  forms  plates  or  flat  white  needles.  ^-Trinitrotoluene  is 
deposited  from  acetone  in  small  hexagonal  crystals,  melting  at  104°. 

Mononitronaphthalene,  C10H7.NO2. — Two  isomers  exist;  the  a-  com- 
pound is  produced  when  ten  parts  naphthalene,  eight  parts  nitric  acid 
(specific  gravity  1.4),  and  ten  parts  sulphuric  acid  (specific  gravity 
1.84)  are  combined  in  a  nitrobenzene  apparatus.  The  naphthalene  is 
added  in  small  portions  and  continually  stirred.  The  product  is  washed 
with  water,  and  freed  from  acid  by  treatment  with  alkali.  Insoluble  in 
water,  easily  in  benzene,  carbon  disulphide,  ether,  and  alcohol.  Crys- 
tallizing in  yellow  needles,  melting  at  61°,  boiling  at  304°.  The  ft-  com- 
pound is  produced  when  /?-nitronaphthylamine  is  melted  with  nitrate 
of  potassa.  Soluble  in  alcohol,  ether,  or  glacial  acetic  acid.  Crystallizes 
in  yellow  needles;  melts  at  79°. 

a-Dinitronaphthalene,  C10H6(NO2)2,  obtained  in  a  similar  manner 
to  the  above.  Difficultly  soluble  in  cold,  easily  in  warm,  benzol.  From 
glacial  acetic  acid  it  crystallizes  in  needles,  melting  at  217°.  /3-Dinitro- 
naphthalene,  isomeric  with  the  above,  crystallizes  in  rhombic  plates, 
melting  at  170°. 

4.  AMINE  DERIVATIVES. — The  amine  derivatives  of  benzene,  toluene, 
and  xylene  can  be  regarded  as  forming  one  of  the  most  important  groups 
of  raw  materials  from  which  are  obtained  the  basic  coloring  matters, 
all  of  which  contain  nitrogen.  The  structure  of  the  amines  can  readily 
be  seen  if  we  employ  ammonia,  NH3,  as  the  type ;  in  this  case  there  are 
three  atoms  of  hydrogen.  If  one  of  these  be  replaced  by  an  organic 


RAW  MATERIALS.  441 

radical,  a  primary  amine  is  produced;  if  two  or  all  three  are  replaced, 
a  secondary  or  tertiary  amine  respectively  is  formed. 

Aniline,  or  Amido-benzene,  C6H5.NH2. — This  substance  was  discov- 
ered by  Unverdorben  in  1826,  who  noticed  its  property  of  combining 
with  acids  to  form  salts.  Runge,  subsequently,  experimenting  upon  coal- 
tar,  found  a  volatile  substance  which,  when  treated  with  a  solution  of 
bleaching-powder,  produced  a  blue  coloration,  giving  rise  to  the  name 
kyanol.  It  was  he  who  noticed  that  when  a  drop  of  the  "nitrate  of 
kyanol"  was  brought  in  contact  with  dried  cupric  chloride,  a  black  spot 
was  formed.  Fritsche,  later,  examined  the  distillation  products  of  indigo, 
and  found  a  body  to  which  he  gave  the  name  aniline.  Aniline  was  for- 
merly obtained  in  large  quantities  by  reducing  the  nitrobenzene  with 
iron  fillings  or  scrapings  and  acetic  acid,  but  now  it  is  wholly  produced 
with  hydrochloric  acid,  the  following  reaction  showing  the  change  that 
occurs : 

(Nitrobenzene.) 

C6H5.NO2  -f  3Fe  -f  6HC1  = 

(Aniline.) 

C6H5.NH2  +  3FeCl2  +  2H20. 

The  quantity  of  acid  represented  by  the  above  equation  is  more  than 
sufficient  for  the  purpose,  from  the  fact  that  ferrous  chloride,  (FeCl2),  a 
reducing  agent  itself,  will  act  in  the  reduction  of  a  further  quantity  of 
nitrobenzene : 

C6H5.N02  +  6FeCl2  +  6HC1  = 
C6H5.NH2  +  3Fe2Cl6  +  2H20. 

Aniline  is  a  liquid,  fluid  at  ordinary  temperatures,  but  when  frozen 
melts  at  — 8°;  boils  at  182°  wrhen  pure;  specific  gravity  1.036;  colorless 
when  freshly  distilled,  but  becomes  reddish-brown  upon  exposure  to  light 
and  air;  impurities  hasten  discoloration.  Soluble  in  alcohol,  ether,  and 
benzene  in  all  proportions;  in  water  it  is  soluble  to  a  slight  extent,  one 
hundred  parts  of  water  dissolving  three  parts  aniline,  while  it,  in  turn, 
dissolves  water  to  the  extent  of  five  per  cent. 

Aniline  forms  a  series  of  well-crystallized  salts,  among  which  are  the 
hydrochloride, — C6H7.N.C1H, — known  as  "aniline  salt,"  largely  em- 
ployed in  the  production  of  black  upon  cotton;  and  the  sulphate, — 
(C6H7N)2H2S04, — of  considerable  importance. 

Methylaniline,  C6H5.NH(CH3),  is  obtained  by  heating  aniline  hydro- 
chloride  or  a  mixture  of  aniline  and  hydrochloric  acid  with  rather  more 
than  a  molecule  of  methyl  alcohol  at  200°  C.  The  product  is  then  con- 
verted into  sulphate  and  the  easily  soluble  sulphate  of  methylaniline 
separated  from  the  sparingly  soluble  aniline  sulphate.  The  sulphate  is 
decomposed  by  an  alkali  and  the  free  base  obtained  by  distillation.  The 
commercial  product  contains  from  ninety  to  ninety-five  per  cent,  of  pure 
methylaniline.  It  is  a  colorless  oil,  boiling  at  192°  C.,  and  has  a  specific 
gravity  0.976  at  15°  C. 

Dimethylaniline,  C0H5.N(CH3)2,  is  obtained  by  heating  a  mixture  of 


442  THE  ARTIFICIAL  COLORING  MATTERS. 

aniline  (seventy-five  parts),  aniline  hydrochloride  (twenty-five  parts), 
and  methyl  alcohol,  free  from  acetone  (seventy-five  parts),  in  a  cast-iron 
autoclave  at  from  230°  to  270°  C.  The  product  is  rectified.  The  yield 
is  about  one  hundred  and  twenty  parts  from  the  above  proportions.  It 
is  a  colorless  oil,  boiling  at  192°  C.,  and  specific  gravity  0.96  at  15°  C. 
Solidifies  at  -f-  5°  C.  to  a  crystalline  solid.  The  commercial  product  is 
usually  nearly  pure. 

Nitramline,  C6H4(N02)NH2. — Both  the  ra-  and  the  p-  nitraniline  are 
used  technically.  The  former  is  made  by  the  partial  reduction  of  dini- 
trobenzene;  the  latter  from  acetanilid,  which  is  nitrated  and  then  freed 
from  the  acetyl  group  by  treatment  with  steam. 

Toluidine,  or  Amido-toluene,  C6H4(CH3)NH2,  occurs  in  three  iso- 
mers,  according  to  the  extent  to  which  the  nitration  of  the  toluene  was 
originally  carried.  Ortho-toluidine  is  produced  by  the  reduction  of 
ortho-nitro-toluene,  by  the  same  means  as  was  applied  in  the  case  of 
aniline.  It  is  a  fluid,  colorless  at  first,  but  becoming  brown  upon  expo- 
sure. Specific  gravity  1.000  at  16°,  boiling  point  197° ;  soluble  to  a 
slight  extent  in  water  (2 : 100)  and  in  alcohol. 

Meta-toluidine,  occurring  similarly  to  the  preceding,  is  a  liquid. 
Specific  gravity  .998,  boiling  at  197°,  little  soluble  in  water,  but  freely 
in  alcohol  and  ether. 

Para-toluidine  is  obtained  in  the  form  of  large  colorless  leaflets,  crys- 
tallizing from  alcohol.  Specific  gravity  .973,  melting  point  45°,  and 
boiling  at  198° ;  slightly  soluble  in  water,  readily  in  alcohol  and  ether. 
Commercial  toluidine  consists  chiefly  of  a  mixture  of  the  ortho-  and  para- 
bodies,  and  containing  very  little  aniline ;  it  is  of  considerable  importance 
in  the  color  industry. 

Xylidine,  or  Amido-xylenc,  C6H3(CH3)2.NH2,  homologous  with  ani- 
line and  toluidine,  is  produced  from  xylene,  as  aniline  is  from  benzene, — 
nitration  followed  by  reduction.  Six  isomers  are  obtainable,  but  the 
xylidine  industrially  employed  consists  of  a  mixture  of  five.  At  ordi- 
nary temperature  it  is  a  liquid,  specific  gravity  .9184  at  25°,  boiling  point 
212°.  From  this  derivative  the  beautiful  series  of  xylidine  scarlets  are 
produced. 

Naphthylamine,  C10H7.NH2. — Two  isomers  exist.  For  a-Naphthylamine 
naphthalene  is  converted  into  the  nitro-  derivative  as  has  been  described, 
and  equal  parts  of  this  body  and  water  are  heated  to  80°,  incorporated 
with  an  equal  part  of  iron  filings,  and  reduced  with  hydrochloric  acid. 
The  product  is  distilled  with  lime,  and  finally  rectified  by  further  dis- 
tillation. Nearly  insoluble  in  water,  soluble  in  alcohol  and  ether;  crys- 
talizes  in  colorless  needles  or  prisms,  which  melt  at  50°,  and  boil  at  300°. 
Upon  contact  with  the  air  it  acquires  a  red  color,  and  oxidizing  agents 
cause  a  blue  precipitate  to  form  in  solutions  of  its  salts.  It  finds  exten- 
sive application  in  the  preparation  of  several  colors  of  importance. 
j3-Naphthylamine  is  produced  when  gaseous  ammonia  combines  with 
/3-naphthol  in  the  fused  state;  commercially  it  is  obtained  by  the  action 
of  ammonio-chloride  of  calcium,  or  ammonio-chloride  of  zinc,  upon  the 
same  body,  assisted  by  heat,  and  the  subsequent  separation  of  by-pro- 


RAW  MATERIALS.  443 

ducts.  It  occurs  in  white  or  pearly  leaflets,  odorless,  difficultly  soluble 
in  cold,  freely  in  hot  water,  and  in  alcohol  and  ether.  Melting  point  112°, 
boiling  at  294°.  Unlike  the  a-naphthylamine,  it  is  not  acted  upon  by 
oxidizing  agents. 

Phenylendiamine,  CGH4(NH2)2. — Both  the  m-  and  the  p-  compounds 
are  used  in  practice.  The  former  is  obtained  by  the  reduction  of  m-dini- 
trobenzene  with  iron  and  hydrochloric  acid;  the  latter  by  the  reduction 
of  amidoazobenzene  with  zinc-dust  in  aqueous  solution. 

CGH4.NH2 

Benzidim    (diamido-diphenyl),    |  . — This   base   is   manufac- 

CGH4.NH2 

tured  on  a  large  scale  as  the  basis  of  the  substantive  cotton  dyes  (see 
p.  464).  For  its  preparation  nitrobenzene  is  reduced  by  zinc-dust  and 
caustic  soda  in  the  presence  of  alcohol.  The  hydrazobenzene  so  obtained 
is  heated  in  the  presence  of  hydrochloric  acid  to  boiling  and  the  benzi- 
dine  precipitated  from  the  solution  by  the  addition  of  sulphuric  acid.  It 
forms  a  grayish- white  crystalline  solid,  fusing  at  122°  C.,  and  rather 
difficultly  soluble  in  water. 

Diphenylamine,  (C6H5)2NH,  is  made  on  a  large  scale  by  heating 
aniline  with  aniline  chlorhydrate  in  autoclaves  to  between  220°  and  230°. 
It  forms  a  white  or  slightly  yellowish  solid,  melting  at  54°,  and  has  a 
pleasant  odor  of  flowers. 

5.  PHENOL  DERIVATIVES. — Phenol,  C6H5OH. — The  occurrence  of  this 
body  has  been  mentioned  under  tar  products,  page  418.  It  crystallizes 
in  needles,  which  have  the  well-known  odor  of  ' '  carbolic  acid. ' '  Specific 
gravity  1.08,  and  melting  at  37.5°,  boiling  at  132°  to  133° ;  soluble  in 
water  (1: 15)  and  readily  in  alkalies,  alcohol,  and  ether.  It  finds  exten- 
sive application  in  the  color  and  other  industries,  large  quantities  being 
consumed  in  the  manufacture  of  picric  acid. 

Resorcin,  or  m-Dioxy~benzene,  C6H4(OH)2,  is  obtained  from  benzene 
by  fusing  the  sodium  sulphonate  of  the  latter  with  caustic  soda.  (See 
page  444.)  Occurs  in  sweetish,  colorless  crystals,  which,  however,  event- 
ually become  dark  colored,  melting  at  110°,  boiling-point,  271°;  readily 
soluble  in  water,  alcohol,  and  ether.  Specific  gravity  1.28. 

Pyrogallol,  or  Trioxy-benzene,  C6H3(OH)3,  is  readily  obtained  from 
gallic  or  tannic  acid  when  the  same  are  heated  to  210°  to  220°.  It  can 
be  obtained  from  benzene,  but  the  above  method  is  more  generally 
adopted.  Processes  for  its  manufacture  are  detailed  on  page  452.  Pyro- 
gallol occurs  in  white  leaflets,  which  melt  at  115°  and  boil  at  210°  ; 
soluble  in  water,  alcohol,  and  ether. 

Naphthols,  C10H7.OH. — The  two  derivatives  of  naphthalene,  a-  and 
/2-naphthol,  find  extensive  application  in  the  manufacture  of  artificial 
coloring  matters.  They  are  prepared  from  the  two  isomeric  naphtha- 
lene sulphonic  acids,  a  and  /?,  which  are  discussed  under  Processes,  page 
452.  a-Naphthol  occurs  as  lustrous  needles,  which  melt  at  94°,  boil  at 
278°  to  280°;  specific  gravity  1.224;  sparingly  soluble  in  hot,  insoluble 
in  cold,  water;  soluble  in  alcohol,  ether,  benzene,  and  in  solution  of 
caustic  alkalies.  /3-Naphthol  occurs  in  leaflets,  melting  at  122°,  boiling 


444 


THE  ARTIFICIAL  COLORING  MATTERS. 


from  285°  to  290°  ;  solubilities  same  as  for  the  preceding.  Allen  (Com- 
mercial Organic  Analysis,  2d  ed.,  vol.  ii,  p.  511)  gives  the  following 
table  of  the  distinguishing  characteristics  of  the  two  naphthols: 


x-Naphthol. 


0-Naphthol. 


Crystallizes  in  small  monoclinic  needles. 
Melting  point  94°  ;  boils  at  278°  to  280°. 
Faint  odor,  resembling  phenol. 
Volatilizes  readily  with  vapor  of  water. 
Aqueous    solution    becomes    dark    violet, 

changing    to   reddish-brown   on   adding 

solution  of  bleaching-powder. 
Aqueous  solution  becomes  red,  and  then 

violet,  on  adding  ferric  chloride. 


Crystallizes  in  rhombic  laminae. 
Melting  point  122° ;  boils  at  285°  to  290°. 
Almost  odorless. 

Scarcely  volatile  with  vapor  of  water. 
Aqueous  solution  colored  pale  yellow  by 
solution  of  bleaching-powder. 

Aqueous  solution  becomes  pale  green  on 
adding  ferric  chloride. 


6.  SULPHO-  ACIDS. — This  group  constitutes  an  interesting  and  techni- 
cally valuable  series  of  bodies,  which  are  obtained  by  the  action  of  con- 
centrated sulphuric  acid  upon  the  hydrocarbons,  or  upon  coloring  mat- 
ters already  formed. 

(1)  Benzene-sulphonic  Acid,  C6H..SO;,H,  is  readily  obtained  by  heat- 
ing two  parts  benzene  with  three  parts  sulphuric  acid  to  100°  C.,  diluting 
with  water,  saturating  with  carbonate  of  lead,  and  decomposing  with 
sulphuric  acid  to  liberate  the  sulphonic  acid.    The  acid  is  soluble  in  water 
and  alcohol,  and  crystallizes  in  small  plates. 

(2)  Benzene-disulphonic  Acids,  C6H4(SO3H)2,  are  (mainly  the  meta 
variety)  produced  when  benzene  is  heated  with  fuming  sulphuric  acid  to 
275°.    Employed  in  the  production  of  resorcin. 

(3)  Toluene-sulphonic  Acid,  C6H4(CH,)S03H. — No  importance. 

(4)  Naphthalene-sulphonic  Acids,  C10H7.SO3H. — Two  isomeric  bodies 
are  obtained  when  naphthalene  is  submitted  to  the  action  of  sulphuric 
acid.     At  temperatures  ranging  from  80°  to  100°  the  a- derivative  is 
largely  obtained,  and  at  temperatures  from  160°  to  170°  the  /3-derivative 
is  produced.     Their  separation  is  based  upon  the  different  degrees  of 
solubility  of  the  lead  salts  upon  concentrating  their  aqueous  solutions, 
a-naphthalene-sulphonic  acid  being  soluble  in  twenty-seven  parts  water, 
while  the  /3-acid  requires  one  hundred  and  fifteen  parts. 

(5)  Anthracene-sulphonic  Acid,  C14Hn.SO3H,  is  produced  similarly 
to  the  above,  or  by  the  reduction  of  sodium  anthraquinone-sulphonate 
with  zinc-dust  and  ammonia. 

Phenol-sulpkonic  Acid,  CfiH4(OH)S03H. — Three  isomers  are  known, 
two,  the  ortho-  and  para-,  being  produced  by  the  direct  action  of  sul- 
phuric acid  upon  phenol,  while  the  meta-  compound  must  be  produced  by 
other  means.  The  ortho-  acid  is  largely  obtained  when  one  part  of  phenol 
is  slowly  mixed  with  one  part  of  sulphuric  acid,  care  being  taken  to 
keep  the  temperature  from  rising.  The  para-  acid  will  be  obtained  if 
the  mixture  be  heated  to  100°.  These  bodies  are  much  employed  as  anti- 
septics under  various  names;  the  para-  compound,  also,  in  the  produc- 
tion of  picric  acid. 


RAW  MATERIALS.  445 

Naphthol-sulphonic  Acids. — The  two  naphthols  are  easily  converted 
into  mono-sulphonic  acids  upon  being  heated  to  100°  C.  with  concen- 
trated sulphuric  acid;  disulphonic  acids  being  produced  if  the  tempera- 
ture reaches  110°  C.  (3-naphthol-sulphonic  add,  C10H6.SO,H.OH.  One 
hundred  parts  of  /?-naphthol  are  added  to  two  hundred  parts  of  sulphuric 
acid  (specific  gravity  1.84)  and  carefully  heated  to  50°  or  60°,  when  two 
acids  result,  ordinary  p-naphthol-sulphonic  acid  (known  also  as 
"Schaffer's  acid,"  or  "acid  S")  and  fi-naphthol-a-sulphonic  acid 
("Bayer's  acid,"  or  "acid  B").  When  converted  into  their  sodium 
salts  they  can  be  separated  by  treatment  with  alcohol,  in  which  men- 
struum the  latter  acid  is  more  soluble  than  the  former.  They  are  exten- 
sively used  for  the  production  of  the  crocei'n  scarlets ;  and  upon  nitration 
yield  other  colors  of  importance.  If  the  mixed  acid  and  naphthol  is 
heated  to  about  20°  C.  Bayer's  acid  will  be  formed,  while  the  employ- 
ment of  a  temperature  about  90°  will  cause  the  formation,  as  the  chief 
product,  of  Schaffer's  acid. 

Disulphonic  Acids  of  (3-Naphthol,  C10H5(S03H)2OH,  are  obtained 
when  the  naphthol  is  subjected  to  a  temperature  of  100°  to  110°  with 
three  times  its  weight  of  sulphuric  acid  (specific  gravity  1.84).  Upon 
dilution  milk  of  lime  is  added,  the  precipitated  calcium  sulphate  filtered 
off,  carbonate  of  soda  added,  and  the  whole  evaporated  to  dryness,  and 
lixiviated  with  alcohol,  when  "salt  G"  (yellow  shade)  is  dissolved  from 
"salt  R,"  red  shade).  Ordinarily,  after  the  addition  of  the  carbonate  of 
soda,  the  solution  is  used  without  further  treatment. 

Anthraquinone-sulphonic  Acid,  C6H4(CO)2C6H3.S03H,  is  formed 
when  anthraquinone  is  treated  with  fuming  sulphuric  acid  at  160°  C.  The 
unaltered  anthraquinone  is  separated,  the  solution  neutralized  with  soda, 
when  the  white  soda  salt  settles  out.  The  free  acid  occurs  in  yellow  plates, 
soluble  in  water  and  in  alcohol.  When  fused  with  either  caustic  soda 
or  potash  alizarin  is  obtained  (when  anthraquinone-disulphonic  acid 
is  used,  either  by  itself  or  in  the  melt,  purpurin  is  produced  along  with 
alizarin)  ;  anthraquinone-sulphonic  acid  being  employed  directly  for  the 
production  of  this  most  valuable  coloring  matter. 

Sulphanilic  (p-amidobenzene-sulphonic)  Acid,  CeH4(HS03)NH2,  is 
made  by  the  action  of  sulphuric  acid  upon  aniline  at  about  190°  C.  Is 
used  very  largely  as  basis  of  the  manufacture  of  dye-colors. 

Naphthylamine-sulphonic  Acids  are  prepared  from  naphthylamine  by 
treatment  with  sulphuric  acid  and  the  application  of  heat.  Several 
derivatives  are  produced,  which,  however,  find  limited  application,  mainly 
in  some  patented  specialties. 

7.  PYRIDINE  AND  QUINOLINE  BASES.— Pyridine,  C5H5N,  is  regarded 
as  a  benzene  nucleus  (C6He)  with  one  of  the  CH  groups  replaced  by  an 
atom  of  nitrogen.  It  is  obtained  wrhen  bone  oil  or  other  nitrogen-contain- 
ing organic  bodies  are  distilled.  It  possesses  a  pungent  odor,  is  liquid, 
boils  at  116.7°,  and  is  soluble  in  water;  specific  gravity  .986.  A  large 
number  of  the  pyridine  derivatives  bear  a  relationship  to  the  alkaloids. 

Quinoline  (Chinoline),  C0H7N,  differs  from  pyridine  in  that  naphtha- 
lene is  the  base,  C10H8,  one  nitrogen  atom  replacing,  as  before,  one  of 


446  THE  ARTIFICIAL  COLORING  MATTERS. 

the  CH  groups.  Quinoline  is  readily  prepared  by  carefully  heating  in  a 
flask  one  hundred  and  twenty  grammes  glycerine,  thirty-eight  grammes 
aniline,  twenty-four  grammes  nitrobenzene  (oxidizing  agent),  with  one 
hundred  grammes  concentrated  sulphuric  acid;  when  the  reaction  is 
over,  boil  for  two  or  three  hours,  dilute  with  water,  and  remove  the 
unchanged  nitrobenzene  with  steam,  saturate  with  caustic  alkali,  distil, 
add  sulphuric  acid  and  sodium  nitrite  (NaNO2)  to  destroy  any  aniline 
present,  make  alkaline,  and  again  distil.  Quinoline  is  a  colorless  fluid, 
having  a  penetrating  odor,  highly  refractive,  becoming  brown  upon  ex- 
posure to  the  air;  boils  at  238° ;  specific  gravity  1.094  at  20°. 

Quinaldine  (a-Methyl-quinoUne) ,  C9H6(CH3)N. — Obtained  by  the 
action  of  hydrochloric  acid  upon  paraldehyde  and  aniline,  for  several 
hours,  with  the  aid  of  heat.  It  has  a  faint  odor,  is  fluid,  and  boils  at  238° 
to  239°.  Technically  employed,  mainly  for  the  production  of  "quino- 
line  yellow,"  cyanine  blue,  quinoline  red,  etc. 

Acridine,  C13H9N. — Anthracene  is  the  base  from  which  this  deriva- 
tive is  obtained  by  a  substitution  of  a  nitrogen  atom  for  one  of  the  CH 
groups.  As  in  the  previous  instances  many  derivatives  of  the  above 
bodies  exist,  which  have  considerable  interest,  but  no  technical  import- 
ance is  attached  to  them  as  raw  materials. 

8.  DIAZO-  COMPOUNDS. — These  form  the  most  extensive,  and  probably 
the  most  thoroughly  investigated  of  the  several  groups  of  coal-tar  colors. 
They  are  produced  when  nitrous  acid  (obtained  from  starch  and  nitric 
acid)  is  allowed  to  act  upon  the  primary  amines  of  the  aromatic  series, 
in  which  case  the  following  change  is  noted,  assuming  aniline  nitrate  to 
be  acted  upon : 

CGH5NH2.HNO3  +  HO.NO  =  C6H.N=:N.N03  +  2H2O. 

(Diazo-benzene  nitrate.) 

Aniline  hydrochloride,  treated  in  the  same  manner,  will  yiel  1  diazo-ben- 
zene  chloride: 

C6H5.NH2.HC1  +  HO.NO  =  CBHBN=N.C1  +  2H20. 

The  diazo-compounds  differ  from  those  of  the  azo-group  in  that  one  of 
the  bonds  of  the  diatomic  nitrogen  group  — N=N —  is  satisfied  with  a 
hydrocarbon  radicle,  while  in  the  latter  it  is  saturated  with  an  atom  of 
oxygen,  nitrogen,  bromine,  chlorine,  etc.,  or  with  an  acid  or  basic  group. 
The  annexed  list  of  diazo-  bodies  illustrates  the  above : 

CaH5N— NCI    Diazo-benzene  chloride. 

(C6HS.N=N)2SO4  "  "  sulphate. 

C8H5N=N.Br  "  "  bromide. 

C«HBN=N.NH.C0H5 Diazo-amido-benzene. 

The  azo-  compounds  have  the  two  nitrogen  atoms  ( —  N  =  N  — ) 
united,  each  to  a  hydrocarbon  group;  mixed  azo-  compounds  result  if 
these  hydrocarbon  groups  are  not  identical. 

(1)   Diazo-benzene  Chloride,  C6H..N2C1,  is  formed  when  nitrite  of 


RAW  MATERIALS.  447 

soda  (NaN02)  is  added  to  a  solution  of  aniline  chloride  in  the  presence 
of  an  excess  of  hydrochloric  acid,  the  solution  being  kept  cool  by  means 
of  ice.  The  product  finds  application  in  the  manufacture  of  aniline 
yellow  and  other  colors. 

Diazo-amido  Compounds  result  from  the  action  of  salts  of  the  diazo- 
derivatives  upon  the  primary  and  secondary  amines. 

Diazo-amido-benzene,  CGH..N2.NH.C6H5,  occurs  when  nitrous  acid  is 
passed  through  a  solution  of  aniline  in  alcohol ;  or  by  adding  a  solution 
of  sodium  nitrite  to  a  mixture  of  aniline  hydrochloride  and  aniline. 
Crystallizes  in  golden-yellow  prisms  or  scales,  insoluble  in  water,  easily 
in  ether,  benzene,  and  alcohol;  melting  point  91°,  exploding  at  a  higher 
temperature. 

(2)  Diazo-benzene-sidphonic  Acid,  C6H4.N2.S03  (the  anhydride  of 
the  sulphonic  acid  of  diazo-benzene). — Sulphanilic  acid,  C6H4NH2.S03H 
(see  p.  445),  is  dissolved  in  water,  and  sodium  nitrite  added,  when  the 
whole  is  poured  into  dilute  sulphuric  acid,  which  causes  a  precipitation 
of  the  crystals. 

9.  AROMATIC  ACIDS  AND  ALDEHYDES. — The  aromatic  acids  form  a 
class  of  bodies  of  considerable  importance,  derived  from  benzenes  by 
substituting  the  carboxyl  group  CO. OH  for  hydrogen.  The  simplest 
of  the  series  is  Benzoic  Acid  (Benzene-carl) oxylic  Acid),  C0H5.CO.OH, 
which,  besides  finding  extensive  application  in  medicine,  is  also  used  in 
the  color  manufacture.  It  can  be  prepared  by  a  number  of  methods, 
chiefly  by  the  sublimation  of  gum  benzoin;  by  treating  the  urine  of 
herbivorous  animals  with  hydrochloric  acid,  which  causes  the  hippuric 
acid  to  break  up,  yielding  the  acid  and  glycocoll ;  and  from  benzotrichlo- 
ride  with  water  under  pressure.  It  crystallizes  in  needles  or  scales,  lus- 
trous, and  odorless  when  pure.  Specific  gravity  1.291,  melting  at  121°, 
and  boiling  at  249° ;  soluble  in  alcohol,  ether,  benzene,  etc.,  sparingly  in 
water. 

Phthalic  acid  (Benzene-dicarb oxylic  Acid},  C6H4.(CO.OH)2. — Three 
isomers  of  the  above  are  known,  but  only  the  ortho-  acid  will  be  consid- 
ered. It  is  obtained  from  naphthalene  tetrachloride  by  heating  with 
nitric  acid  or  more  generally  at  present  by  treating  naphthalene  with 
strong  sulphuric  acid  in  the  presence  of  mercury.  It  occurs  in  rhombic 
crystals,  specific  gravity  1.585,  and  melting  at  213° ;  upon  being  heated, 
it  is  liable  to  split  up  into  water  and  the  anhydride;  soluble  in  hot 
water,  alcohol,  and  ether.  When  a  phenol  is  heated  with  the  phthalic 
anhydride  phthale'ms  result;  of  these,  the  resorcin  and  pyrogallol- 
phthale'ins  are  the  most  important,  being  the  bases  of  the  eosins  and 
galle'ms  and  ccerulems. 

Gallic  Acid  (Trihijdroxybenzoic  Acid),  C6H2(OH)3.CO.OH.— This 
acid  occurs  in  several  vegetable  substances, — chiefly  gallnuts,  sumach, 
tea,  etc.  It  is  ordinarily  prepared  by  heating  gallo-tannic  acid  with 
dilute  mineral  acid,  or  by  allowing  crushed  galls  to  remain  exposed  in  a 
moistened  state  to  the  action  of  the  atmosphere  for  some  time,  when  a 
fermentation  takes  place,  after  which  boiling  with  water  removes  the 
gallic  acid.  It  yields  needle-shaped  crystals,  sometimes  white,  but  mostly 


448  THE  ARTIFICIAL  COLORING  MATTERS. 

light  brown  in  color.  Specific  gravity  1.70.  When  heated  to  220°  it 
decomposes,  forming  pyrogallol  (Trihydroxybenzene,  C6H3(OH)3)  and 
C02.  Gallic  acid  is  the  chief  source  of  pyrogallol,  reference  to  the  appli- 
cation of  which  has  been  made  under  phthalic  acid. 

Benzaldehyde  (Benzoic  Aldehyde},  C6H5.CO.H.  —  This  body,  also 
known  as  "Bitter  Almond  Oil,"  is  a  colorless  liquid,  possessing  an  agree- 
able odor,  and  high  refracting  power.  Specific  gravity  1.063,  boiling  at 
180°,  difficultly  soluble  in  water  (1:300),  easily  in  alcohol  and  ether. 
Several  methods  are  employed  for  the  production  of  this  substance;  for 
industrial  purposes,  benzyUchloride  is  boiled  with  nitrate  of  copper 
and  water,  half  of  the  contents  are  distilled,  when  the  oil  layer  is  sepa- 
rated from  the  distillate  and  purified.  Mercuric  oxide  has  been  used 
instead  of  the  copper  salt.  It  finds  extensive  application  in  the  color  in- 
dustry, also  for  the  production  of  cinnamic  and  benzoic  acid,  and  several 
derivatives  of  value. 

10.  KETONES  AND  DERIVATIVES,  ANTHRAQUINONE.  —  The  ketones  are 
closely  related  to  the  aldehydes,  as  will  be  seen  from  their  structure,  — 
CH3  —  CO  —  H,  Aldehyde,  CH3  —  CO  —  CH3,  Dimethyl-ketone  (ace- 
tone). 

The  CO  group  —  carbonyl  —  is  possessed  by  both  classes,  but  in  the 
aldehydes  is  united,  on  the  one  hand  to  an  alcohol  radical,  and  on  the 
other  to  an  atom  of  hydrogen.  The  ketones,  however,  are  distinguished 
by  having  two  alcohol  radicals  (alkyls)  linked  by  the  CO  group. 

Benzophenone,  C6H5.CO.C6H5,  is  a  ketone  of  the  benzene  series,  and 
can  be  obtained  by  distilling  calcium  benzoate,  or  by  heating  benzoyl 
chloride  with  aluminum  chloride  and  benzene.  It  occurs  in  crystals  hav- 
ing an  aromatic  odor,  and  which  melt  at  48°  to  49°,  subliming  at  300°. 
Insoluble  in  water,  soluble  in  alcohol  and  ether.  It  is  of  some  import- 
ance, together  with  the  amido-  and  oxy-  derivatives,  in  the  manufacture 
of  certain  colors. 

Acetophenone  (Phenyl-methyl-ketone}  ,  C6Hr,.CO.CH?>.  —  This  is  a 
mixed  ketone,  and  contains  two  residues  of  different  hydrocarbons  united 
to  the  carbonyl  group.  Acetophenone  can  be  obtained  by  distilling  a 
mixture  of  the  benzoate  and  acetate  of  calcium.  It  occurs  in  crystalline 
plates,  melting  at  14°  to  15°,  and  boils  at  198°. 

Anthraquinone,  C6H4/^       \CGH4.  —  This  substance  is  of  the  utmost 


importance  in  the  manufacture  of  alizarine.  It  can  be  obtained  by  sev- 
eral processes,  the  simplest  of  which  is  probably  the  distillation  of  cal- 
cium phthalate,  or  by  oxidizing  anthracene  (C10HS)  with  bichromate  of 
potash  and  sulphuric  acid.  Anthraquinone  is  very  stable,  oxidizing 
agents  having  but  little  effect  upon  it.  When  heated  it  sublimes,  yielding 
yellowish  rhombic  crystals.  Specific  gravity  1.425,  melting  point  273°  ; 
insoluble  in  water,  but  somewhat  in  alcohol  and  ether.  Upon  fusion  with 
caustic  alkalies  it  yields  benzoic  acid.  For  use  in  the  alizarine  process, 
it  must  be  converted  into  the  sulphonic  acid,  and  this  fused  with  caustic 
alkali,  dissolved  in  water,  and  the  coloring  matter  precipitated  by  a 
mineral  acid,  and  sublimed.  (See  Process  of  Manufacture,  p.  453.) 


PROCESSES  OF  MANUFACTURE.  449 


II.  Processes  of  Manufacture. 

1.  OF  NITKOBENZENE  AND  ANILINE. — The  commercial  production  of 
nitrobenzene  is  carried  out  essentially  in  the  following  manner,  although 
the  details  may  vary  in  the  different  works.  Sulphuric  acid,  66°  Be., 
and  nitric  acid,  42°  Be  (  =  seventy  per  cent.  HNO3),  are  mixed  together, 
in  the  proportion  of  fifteen  parts  by  weight  of  the  former  to  ten  parts 
of  the  latter,  in  a  lead-lined  wood  tank  (preferably  situated  above  the 
nitrating  apparatus)  and  allowed  to  become  cold.  Three  hundred  pounds 
of  this  "nitrating  acid"  are  run  into  the  nitrating  apparatus,  either  by 
gravity  or  by  pressure,  when  the  benzene  is  allowed  to  flow  in  in  a  slow, 
steady  stream.  During  the  admission  of  the  benzene  the  temperature, 
which  should  be  maintained  between  80°  C.  and  90°  C.,  is  regulated  by 
means  of  water  kept  at  about  50°  C.  circulating  around  the  vessel,  or 
stopping  the  inflow,  should  the  temperature  give  indication  of  rising, 
thereby  producing  the  dinitro-  derivative.  About  one  hundred  pounds 
of  benzene  are  used,  although  this  quantity  is  subject  to  change,  accord- 
ing to  quality.  After  the  nitration  is  finished,  the  contents  of  the  vessel 
are  emptied  slowly  into  large  tanks,  the  acid  layer  being  drawn  off  first, 
and  the  nitric  acid  recovered  therefrom,  and  the  nitrobenzene,  insoluble 
in  the  acid,  coming  last,  is  immediately  poured  into  a  tank  containing 
water,  and  washed,  followed  by  a  wash  with  caustic  alkali,  and  finally 
agitated  with  water. 

The  quantities  by  weight  of  the  two  acids  to  effectually  nitrate  either 
benzene,  toluene,  or  xylene,  are  shown  below: 

100  kilos,  benzene.  ...  120  kilos,  nitric  acid.     180  kilos,  sulphuric  acid. 
100     "         toluene....  150       "          "         "          175     "  "  " 

100     "        xylene 90       "  "         "         150     " 

Or,  of  a  standard  mixture  of  one  hundred  kilos,  nitric  acid  and  one  hun- 
dred and  fifty  kilos,  sulphuric  acid,  there  will  be  required  for  the  effect- 
ual nitration  of  one  hundred  kilos,  of  the  above  tabulated  hydrocarbons 
three  hundred,  two  hundred  and  sixty,  and  two  hundred  and  twenty-five 
kilos,  respectively.  The  form  of  nitrating  apparatus  in  use  is  usually 
cylindrical,  with  a  flat  or  round  bottom.  Fig.  109  illustrates  the  latter 
form.  The  cover  is  provided  with  several  openings:  f  is  for  general 
charging;  e  is  for  the  gas  exit,  while  provision  is  made  for  the  intro- 
duction of  the  thermometer,  and  for  carrying  the  agitator  shaft.  The 
opening  for  withdrawing  the  charge  is  at  g.  The  best  plan  in  arranging 
the  plant  is  to  provide  for  the  acid  mixing  and  nitrating  on  one  floor,  on 
the  floor  below  the  washing,  and,  if  desirable,  a  steam  still  employed  to 
separate  the  benzene  which  has  not  been  acted  on  by  the  acids,  and  which 
is  always  found  dissolved  in  the  nitrobenzene.  On  the  lowest  floor,  the 
alkali  and  final  water-wash.  If  all  the  operations  are  performed  on  one 
level,  a  "monte-jus"  should  be  used  for  the  transportation  of  liquids. 

Aniline  ("Aniline  Oil"  of  commerce). — Aniline  is  obtained  by  the 
treatment  of  nitrobenzene  with  iron  filings  or  scrapings  and  hydrochloric 


450 


THE  ARTIFICIAL  COLORING  MATTERS. 


acid.  The  apparatus  employed  are  generally  of  two  kinds,  vertical  and 
horizontal,  the  method  of  working  being  in  each  case  the  same.  In  the 
former,  the  agitator  is  attached  to  an  upright  hollow  shaft,  so  constructed 
as  to  provide  for  the  admission  of  steam  to  the  bottom  of  the  vessel.  The 
cover  supports  the  gearing,  and  gooseneck  for  leading  the  vapors  to  the 
condenser,  etc.  The  horizontal  form  is  shown  in  Fig.  110 ;  the  construc- 
tion provides  for  agitators  attached  to  a  horizontal  revolving  shaft  pass- 

FIQ.  109. 


ing  through  boxes  in  the  heads.  Steam  enters  through  the  pipes  under- 
neath. A  steady  supply  of  fine  iron  is  maintained  by  means  of  the 
mechanical  feed  on  the  cover.  The  operation  is  conducted  by  adding 
some  of  the  iron  fillings  with  water,  followed  by  the  acid  and  nitro- 
benzene; steam  is  turned  on,  and,  the  agitators  set  in  motion,  at  once 
the  reaction  begins,  and  a  mixture  of  nitrobenzene,  aniline,  and  water 
appears  in  the  condenser,  which  is  continually  returned  to  the  main 
body  in  the  apparatus;  after  the  reaction  has  commenced  and  the  dis- 


PROCESSES  OF  MANUFACTURE. 


451 


FIG.  110. 


tillate  comes  over  regularly,  the  iron  can  be  fed  steadily,  or  at  uniform 
intervals.  If  all  the  iron  is  added  at  once,  serious  loss  is  occasioned  by  a 
reduction  of  aniline  to  benzene  and  ammonia.  For  a  charge  of  six  hun- 
dred kilos,  of  nitrobenzene,  about  seven  hundred  kilos,  of  iron  filings 
will  be  required  and  sixty  kilos,  of  21°  Be.  hydrochloric  acid.  The  solu- 
bility of  the  distillate  in  hydrochloric  acid  is  noted,  until  a  point  is 
reached  at  which  no  nitrobenzene  separates  in  an  unaltered  condition. 
Formerly  it  was  the  general  practice  to  add  lime  to  the  tank,  and  distil 
off  the  aniline  by  means  of  steam;  now  the  contents  are  emptied  into 
large  tanks  containing  water  and  allowed  to  subside  for  a  day  or  more, 
when  the  lower  layer,  consisting  of  aniline,  is  drawn  off  and  pumped 
into  a  large  iron  still  mounted  over  an  open  fire  and  rectified.  One 
hundred  parts  of  nitrobenzene  will 
yield  about  seventy-five  parts  of  aniline 
if  the  process  is  carefully  attended. 
Ordinarily,  the  yield  will  be  from 
seventy-one  to  seventy-four  parts. 

2.  OF  PHENOLS,  NAPHTHOLS,  ETC. — 
Phenol— See  Chapter  XL,  "  Coal- 
tar  Distillation,"  p.  418. 

Besorcin  is  manufactured  commer- 
cially from  the  soda  salt  of  meta- 
benzene-disulphonic  acid,  by  fusing 
with  caustic  soda  and  subsequent  ex- 
traction with  ether.  One  hundred 
kilos,  of  fuming  sulphuric  acid  are 
contained  in  a  large  cast-iron  vessel 
provided  with  means  for  agitating  the 
contents,  and  into  it  is  gradually  al- 
lowed to  flow  twenty-eight  kilos,  of 

benzene;  the  whole  is  maintained  at  a  moderate  temperature  for  sev- 
eral hours,  and  finally  raised  to  about  270°  C.  to  275°  Cv  after  which 
the  contents  are  transferred  to  a  large  volume  of  water  and  boiled.  Lime 
is  added,  the  precipitated  sulphate  removed,  and  the  soluble  lime  salt 
decomposed  by  the  addition  of  the  requisite  quantity  of  carbonate  of 
soda ;  carbonate  of  lime  is  precipitated,  filtered,  and  the  precipitate  freed 
from  the  excess  of  solution  in  the  filter-press.  This  solution  is  evap- 
orated to  dryness  in  iron  pans.  For  the  resorcin  melt,  sixty  kilos,  of  the 
above  salt  and  one  hundred  and  fifty  kilos,  of  76°  caustic  soda  are  fused 
together  for  about  eight  hours  at  a  temperature  near  270° ;  when  fusion 
is  finished  the  melt  is  cooled,  leached  out  with  boiling  water,  and  boiled 
with  hydrochloric  acid  for  some  time,  when  the  heat  is  withdrawn,  and 
the  solution  allowed  to  become  cold,  and  subjected  to  the  action  of  ether 
or  benzene  in  an  extraction  apparatus,  which  removes  the  resorcin.  The 
benzene  is  distilled  off  and  recovered,  while  the  crude  resorcin  remaining 
is  dried  at  about  210°.  Pure  resorcin  is  obtained  from  the  above  by 
distillation. 

Pyrogallol. — Several  processes  are  employed  for  the  production  of 


452  THE  ARTIFICIAL  COLORING  MATTERS. 

this  substance,  all  being  based  upon  the  use  of  an  aqueous  extract  of 
gallnuts  or  of  gallic  acid.  One  process  is  carried  out  by  heating  a  gly- 
cerine solution  of  gallic  acid  to  about  200°  C.,  diluting  with  an  equal 
volume  of  water,  and  extracting  therefrom  the  pyrogallol  with  ether, 
which  is  evaporated  off  and  recovered.  Another  process  is  to  heat  one 
part  of  gallic  acid  and  two  parts  water  in  a  closed  vessel  to  200°  to  210° 
C.  for  half  an  hour,  when  it  is  cooled,  and  heated  with  bone-black,  the 
solution  filtered,  and  evaporated  to  the  crystallizing-point.  The  crystals 
are  further  purified  by  being  distilled  in  a  vacuum. 

Alpha-  and  Beta-  Naphthols. — a-Naphthol  is  manufactured  on  a  large 
scale  in  the  same  general  manner  as  resorcin.  a-Naphthalene-sulphonic 
acid  is  first  prepared  by  heating  naphthalene  with  fuming  sulphuric 
acid  to  90°  C.,  diluting  with  water,  and  completely  neutralizing  with 
milk  of  lime,  filtering  from  the  magma  of  sulphate  which  is  passed 
through  a  filter-press,  the  solution  of  the  soluble  lime  salt  decomposed 
with  carbonate  of  soda,  filtered  and  pressed  again  and  the  solutions  finally 
evaporated  to  crystallization,  when,  on  cooling,  the  /3-naphthalene-sul- 
phonate  separates  out  and  is  removed.  The  a-  salt  is  fused  with  caustic 
soda,  when  the  corresponding  naphthol  is  obtained. 

(3-Naphthol,  of  much  more  commercial  importance  than  the  preceding, 
is  manufactured  similarly.  The  naphthalene-sulphonic  acid  is  made  as 
above,  but  at  a  temperature  of  200°  C.,  in  order  to  obtain  a  large  yield 
of  the  ^-derivative.  This  is  converted  into  the  soda  salt,  dried,  and  one 
part  by  weight  fused  with  two  parts  of  caustic  soda  dissolved  in  the 
smallest  quantity  of  water,  at  a  temperature  of  270°  to  300°  C. ;  when 
the  reaction  is  over,  the  melt  is  treated  with  water,  the  /?-naphthol  sepa- 
rated by  the  addition  of  hydrochloric  acid,  filtered,  dried,  melted,  and 
poured  into  cylindrical  moulds. 

3.  OF  AROMATIC  ACIDS  AND  PHTHALEINS. — Benzoic  Acid  can  be  man- 
ufactured by  several  processes  and  from  different  sources.  For  technical 
purposes  the  manufacture  from  benzoin  resin  and  from  hippuric  acid 
need  not  be  considered,  as  it  is  made  almost  exclusively  on  a  large  scale 
from  the  chlorine  derivatives  of  toluene,  such  as  benzal  chloride, 
C6H5.CHC12,  and  benzo-trichloride,  C6H5CC13.  The  former,  when  heated 
with  water  or  milk  of  lime  under  pressure,  is  changed  into  benzaldehyde, 
C6H5CHO,  which,  however,  always  has  some  benzoic  acid  formed  with 
it  as  a  side-product.  The  benzo-trichloride,  similarly  with  water  or 
milk  of  lime,  yields  benzoic  acid  according  to  the  reaction  CP,H5.CC13  -f- 
2H20  —  C6H5.COOH  4-  3HC1.  The  benzoic  acid  so  obtained  is  almost 
always  contaminated  by  some  chlorbenzoic  acid. 

Phthalic  Acid  and  Phthalic  Anhydride. — The  process  for  their  manu- 
facture at  present  preferred  is  to  heat  one  hundred  parts  of  naphthalene 
with  fifteen  hundred  parts  of  concentrated  sulphuric  acid  and  fifty  parts 
of  mercuric  sulphate.  The  naphthalene  at  first  goes  into  solution  as  a 
sulpho  acid,  which,  on  heating  gradually  to  300°  C.,  is  decomposed  with 
liberation  of  sulphur  dioxide,  carbon  dioxide,  and  water,  phthalic  acid 
then  distilling  over.  On  cooling  a  mixture  of  phthalic  acid  and  phthalic 
anhydride  separates  out,  which  is  drained  and  purified.  The  anhydride 


PROCESSES  OF  MANUFACTURE.  453 

is  obtained  by  acting  upon  phthalic  acid,  heated  to  about  200°  C.,  with 
carbon  dioxide  and  subliming. 

Phthale'ins. — When  phthalic  acid  or  its  anhydride  acts  upon  phenols 
a  class  of  bodies  termed  "phthaleins"  are  formed  with  elimination  of 
water.  Phenolphthalein  is  manufactured  by  heating  the  anhydride, 
phenol,  and  sulphuric  acid  for  ten  to  twelve  hours  at  120°  C. ;  the  sul- 
phuric acid  acts  only  as  a  dehydrating  agent.  The  melt  is  boiled  with 
water,  the  residue  dissolved  in  caustic  soda,  and  the  phthalem  is  pre- 
cipitated upon  the  addition  of  an  acid.  Resorcin-phthale'in,  or  Fluor- 
escein,  is  obtained  by  heating  three  parts  of  phthalic  anhydride  with 
about  four  parts  of  resorcin  until  the  fusion  yields  no  more  vapors,  and 
becomes  solid  at  a  temperature  not  exceeding  210°  C.  The  melt  is  dis- 
solved in  dilute  caustic  soda,  with  an  addition  of  phosphate  of  soda  and 
chloride  of  calcium  to  remove  impurities.  The  fluoresce'in  is  precipitated 
from  the  solution  by  the  addition  of  dilute  hydrochloric  acid. 

4.  OF  ANTHRAQUINONES,  ETC. — Anthracene  in  a  finely-divided  state 
is  suspended  in  water  by  agitation,  and  oxidized  by  means  of  potassium 
bichromate  and  sulphuric  acid  at  a  boiling  temperature ;  allowed  to  cool, 
and  the  anthraquinone  is  collected  on  filter-frames,  washed  with  water 
and  dried,  and  for  further  purification  is  treated  with  concentrated 
sulphuric  acid,  and  heated  to  110°  to  120°  C.,  when  the  dark  mass 
obtained  is  treated  with  steam,  which  causes  a  dilution,  followed  by  a 
gradual  separation  of  the  anthraquinone  in  crystals.  These  are  washed 
with  hot  water,  and  afterwards  with  hot  dilute  soda  to  remove  organic 
acids.  The  yield  is  about  fifty  to  fifty-five  per  cent,  of  the  weight  of 
the  anthracene  used. 

Anthraquinone-monosulphonic  Acid.  (See  p.  445.) — This  is  manu- 
factured by  heating  one  hundred  kilos,  anthraquinone  with  one  hundred 
kilos,  fuming  sulphuric  acid  (containing  forty-five  to  fifty  per  cent, 
anhydride)  to  160°  C.  in  an  enamelled  cast-iron  vessel  mounted  in  an  oil- 
bath.  By  varying  either  the  quantity  of  sulphuric  acid  or  the  tempera- 
ture the  alpha-  or  beta-disulphonic  acid  will  result.  The  separation  of 
the  two  latter  from  the  monosulphonic  acid  is  effected  by  converting  the 
sulphonic  acids  into  lead  salts,  decomposing  these  with  carbonate  of  soda, 
and  acting  upon  the  resulting  soda  salts  with  dilute  sulphuric  acid,  which 
has  but  a  slight  solvent  action  upon  the  monosulphonic  acid. 

Alizarin. — The  alizarin  process  is  carried  on  in  large  vessels  or  auto- 
claves, mounted  as  shown  in  Fig.  111.  To  the  central  shaft  Z>  agitators 
are  attached,  so  that  the  charge  may  be  constantly  mixed.  F  is  a  ther- 
mometer, and  the  openings  in  the  top  to  the  right  are  for  introducing  the 
charge,  and  the  small  one  on  the  left  for  admitting  steam  and  water. 
The  process  is  commenced  by  melting  two  hundred  and  fifty  to  three 
hundred  parts  of  caustic  soda  in  a  small  quantity  of  water,  and  then 
adding  twelve  to  fifteen  parts  of  chlorate  of  potash  and  one  hundred 
parts  of  the  sodium  anthraquinone-sulphonate,  when  the  vessel  is  closed 
and  the  agitator  put  in  motion,  the  whole  being  kept  at  a  temperature 
of  180°  C.  for  two  days,  when  it  is  allowed  to  cool,  dissolved  in  a  large 
quantity  of  water,  and  the  alizarin  precipitated  by  the  addition  of  hydro- 


454 


THE  ARTIFICIAL  COLORING  MATTERS. 


chloric  acid.  The  alizarin  is  washed  to  free  it  from  soda  salts,  passed 
through  filter-presses,  and  is  ready  to  be  either  dried  and  ground,  or 
ground  in  glycerine  to  a  paste.  Neutralizing  the  soda  solution  with  sul- 
phurous acid  instead  of  with  hydrochloric  acid  enables  a  recovery  of  the 
caustic  soda.  The  yield  from  one  hundred  kilos,  anthraquinone  is  one 
hundred  and  five  to  one  hundred  and  ten  kilos,  alizarine  (Schultz).  Sev- 
eral processes  are  employed,  varying  mainly  in  the  duration  of  the  melt 
and  in  the  proportion  of  materials  used.  Instead  of  soda,  lime  is  em- 
ployed, in  which  case  a  ' '  lake ' '  is  formed. 

FIG.  111. 


5.  OF   QUINOLINE    (CHINOLINE)    AND  ACRIDINE. — Quinoline   is  pro- 
duced from  nitrobenzene  and  aniline.     Twenty-four  grammes  of  the 
former  and  thirty-eight  grommes  of  the  latter,  with  one  hundred  and 
twenty  grammes  of  glycerine,  are  placed  in  a  flask   (provided  with  a 
return  condenser)  containing  one  hundred  grammes  of  concentrated  sul- 
phuric acid;  when  the  reaction  is  over,  the  contents  are  boiled  for  some 
time,  diluted,  and  the  unconsumed  nitrobenzene  is  distilled  off ;  an  excess 
of  alkali  is  added  to  the  solution,  and  the  quinoline  distilled  off  with 
a  current  of  steam.    It  can  also  be  obtained  from  crude  quinoline  from 
coal-tar  with  phthalic  anhydride  and  zinc  chloride.     Acridine  is  found 
along  with  crude  anthracene,  from  which  it  is  separated  by  treatment 
with  dilute  sulphuric  acid,  precipitating  with  chromate  of  potash,  recrys- 
tallizing,  precipitating  by  ammonia,  dissolving  in  hot  water,  from  which 
it  separates  in  crystals  on  cooling. 

6.  SULPHONATING. — This  general  process  consists  in  dissolving  the 


PRODUCTS.  455 

compound  to  be  changed  in  fuming  sulphuric  acid,  whereby  one  or  more 
H  atoms  are  replaced  by  HSO3  groups,  producing  mono-,  di-,  or  trisul- 
phonic  acids.  Examples  of  this  process  are  given  under  Resorcin  (see  p. 
451),  the  Naphthols  (see  p.  452 ),  and  will  frequently  be  referred  to  in 
classifying  the  artificial  dye-colors. 

7.  DIAZOTIZING. — By  the  action  of  nitrous  acid  upon  primary  aromatic 
amines  a  diazo-  compound  is  formed,  as  in  the  following  reaction: 

C6H5.N!  H2H  !  N03  =  C0H5.N=N.N03  -f  2H20. 

+  NJ  O.H! 

These  diazo-  compounds  are  susceptible  of  a  great  variety  of  reactions 
whereby  other  groups  or  atoms  of  elements  may  be  substituted.  Thus,  by 
the  aid  of  the  diazotizing  reaction  it  is  possible  to  replace  a  N02  or  a  NH2 
group  by  OH,  H,  Cl,  Br,  I,  CN,  etc.  It  is  therefore  of  the  greatest 
importance  in  synthetic  organic  chemistry. 

The  process  is  carried  out  in  one  of  two  general  ways:  (a)  by  con- 
ducting a  current  of  nitrous  acid  gas  through  a  solution  of  the  substance 
to  be  diazotized,  the  nitrous  acid  in  this  case  being  most  conveniently 
obtained  by  acting  upon  starch  with  concentrated  nitric  acid  in  a  suitable 
generator,  or  (&)  by  diazotizing  in  a  bath  together  with  the  nitrous  acid- 
yielding  substance  (nitrite  of  soda  generally).  In  this  case  the  gas  is 
evolved  by  adding  an  acid,  usually  sulphuric,  to  the  solution.  Diazo- 
tizing is  always  conducted  at  a  low  temperature. 

The  development  of  productive  values  from  coal  by  distillation  and 
working  up  of  the  intermediate  products  to  those  classed  as  final  pro- 
ducts is  thus  shown  by  Ost  (Lehrbuch  der  Chem.  Technol.,  6th  ed.,  p. 
555): 

1000  kilos,  of  coal  valued  at  10  marks  yield — 

700  kilos,  of  coke,  valued  at  10.5  marks ;  30  kilos,  of  coal-tar  valued 
at  0.7  mark ;  6  kilos,  of  impregnating  oils  valued  at  0.25  mark ;  15 
kilos,  of  pitch  valued  at  0.6  mark;  1.1  kilos,  of  ammonium  sul- 
phate valued  at  2.75  marks;  and  1  kilo,  of  potassium  cyanide 
valued  at  1.3  marks. 
30  kilos,  of  coal-tar  valued  at  0.7  mark  yield — 

5  kilos,  of  benzol  valued  at  1.1  marks;  2  kilos,  of  naphthalene 
valued  at  0.16  mark;   0.25  kilo,   of  anthracene  valued   at  0.07 
mark;  and  0.15  kilo,  of  carbolic  acid. 
From  these  intermediate  products  are  obtained: 

2.5  kilos,  of  fuchsine  valued  at  16  marks;  0.75  kilo,  of  indigo  val- 
ued at  6  marks;  0.2  kilo,  of  alizarine  valued  at  1.4  marks;  and 
0.2  kilo,  of  picric  acid  valued  at  0.35  mark. 

m.  Products. 

It  would  be  impossible  in  the  space  of  this  chapter  to  do  more  than 
give  a  classification  of  the  artificial  dye-colors  and  enumerate  a  few  of  the 
more  important  under  each  group.  The  number  of  distinct  products  has 
already  run  far  into  the  thousands,  and  the  trade-names  by  which  many 


456  THE  ARTIFICIAL  COLORING  MATTERS. 

are  exclusively  known  frequently  bear  so  little  relation  to  the  chemical 
names  that  it  would  be  idle  for  us  to  attempt  to  cover  the  ground  in  any 
other  way  than  by  a  simple  outlining  at  present.  But  before  taking  up 
this  classification  it  will  be  well  to  examine  what  general  principles,  if 
any,  underlie  the  production  of  a  dye-color.  O.  N.  Witt  *  has  proposed 
a  theory  which  explains  in  a  very  simple  way  this  color  formation  in  the 
aromatic  series.  He  names  a  series  of  radicals  or  groups  which  by  their 
entrance  alone  or  with  others  change  a  colorless  hydrocarbon  into  a 
colored  compound.  These  radicals,  which  he  calls  ' '  chromophor  "  groups, 
are  only  capable  of  producing  the  ' '  chromogens, "  or  parent  substances  of 
dye-colors,  which  chromogens,  however,  are  at  once  changed  into  dye- 
colors  of  distinct  basic  or  acid  character  when  a  salt-forming  group 
enters.  Thus,  from  two  molecules  of  benzene  by  the  entrance  of  the 
chromophor  group  — N=N —  is  formed  azo-benzene,  an  orange-colored 
chromogen,  but  not  capable  of  dyeing  silk  or  wool.  When  the  NH,  group 
enters  there  results,  however,  amido-azo-benzene,  a  real  dyestuff.  Or 
from  benzene  by  the  entrance  of  the  chromophor  group  NO,  is  formed 
the  chromogen  trinitro-benzene,  which  by  the  entrance  of  the  salt-form- 
ing group  OH  becomes  trinitro-phenol  (or  picric  acid),  a  yellow  dye- 
color. 

Witt  indicates  some  eleven  of  these  chromophor  groups,  to  which  we 
shall  refer  under  the  appropriate  heads  in  our  classification.  Of  salt- 
forming  groups  which  change  the  chromogens  to  dyestuffs,  two  are 
specially  to  be  noted,  the  amido  group  NH2,  which  imparts  a  basic  char- 
acter to  the  dye-color,  and  the  hydroxyl  group  Oil,  which  gives  the  dye- 
color  an  acid  character.  Almost  all  dye-colors  are  changed  to  colorless 
compounds  by  the  action  of  reducing  agents.  The  nitro-  compounds  are 
changed  into  the  corresponding  amido-  derivatives,  the  azo-  compounds 
into  hydrazo-  or  even  amido-  compounds,  while  more  complex  dye-colors 
are  changed  by  careful  reduction  into  bodies  richer  in  hydrogen,  which 
are  known  as  "leuco"  compounds.  From  these  "leuco"  compounds  the 
corresponding  dye-colors  are  then  formed  more  or  less  easily  by  oxida- 
tion. In  some  cases  atmospheric  oxidation  alone  suffices,  as  with  indigo, 
in  others  more  energetic  oxidizing  agents,  such  as  lead  peroxide,  are 
needed. 

Again,  the  study  of  dye-colors  soon  shows  that  they  possess  different 
characters  with  reference  to  the  ease  with  which  they  may  be  fastened 
upon  the  fibre  to  be  dyed  or  the  kind  of  mordant  needed  to  effect  such 
fastening  upon  the  fibre.  We  therefore  distinguish  between  basic,  acid. 
and  indifferent  or  neutral  dyestuffs.  Basic  dyes  like  magneta  fasten 
upon  the  animal  fibre  at  once,  and  upon  the  vegetable  fibres  after  treat- 
ment with  tannic  acid  and  similar  acid  mordants.  They  are  used  in  the 
form  of  their  salts.  The  acid  dyes  are  frequently  sparingly  soluble,  and 
are  either  brought  into  soluble  condition  by  forming  alkaline  salts  and 
sulphonic  derivatives,  which  are  then  used  for  dyeing,  or  they  are  used 
with  fibres  previously  mordanted  with  metallic  hydroxides  or  salts,  as  in 

*  Berichte   der    Chem.    Ges.,    ix,   p.    522. 


PRODUCTS.  457 

the  case  of  alizarin.  In  the  latter  case,  however,  the  color  acid  forms  a 
variety  of  different  colored  compounds  (lakes)  with  the  different  bases. 
To  the  third  class  (indifferent  or  neutral  bodies)  belong  indigo-blue 
and  some  other  substances. 

The  classification  which  is  now  generally  accepted  is  that  based  in  the 
main  upon  Witt's  chromophor  groups,  and  we  will  simply  note  a  few 
illustrative  compounds  under  each  group. 

1.  ANILINE  OR  AMINE  DYE-COLORS. 

/  Q  _.  » 

(&)  TRIPHENYL-METHANE  DYES  (  Chromophor  group,      ^_J    N— )• — 

Benzaldehyde  Green  (or  Malachite  Green),  known  also  under  a  variety 
of  other  names,  is  made  by  the  action  of  benzaldehyde  upon  dimethyl- 
aniline.  The  commercial  dye  is  the  oxalate  or  zinc  chloride  double  salt. 

Brilliant  Green  (or  Solid  Green)  is  the  corresponding  derivative 
from  diethyl-aniline.  The  sulphate  or  zinc  chloride  salt  is  used  as  dye. 

Magenta  (Aniline  Red,  or  Fuchsine)  is  a  mixture  of  the  chlorhydrates 
of  para  rosaniline  and  rosaniline,  and  is  obtained  by  oxidizing  aniline 
oil  with  arsenic  acid  or  nitrobenzene.  A  large  number  of  side-products 
are  obtained  in  the  manufacture  of  magenta,  and  have  been  used  under 
the  names  of  cerise,  cardinal,  amaranth,  chrysaniline,  phosphine,  maroon, 
mauvaniline,  etc. 

Acid  Magenta  (Fuchsine  S)  is  the  sodium  or  ammonium  salt  of  para- 
rosaniline  and  rosaniline  trisulphonic  acids,  and  is  prepared  by  sulpho- 
nating  the  ordinary  magenta. 

Aniline  Blue  (spirit  soluble  Blue)  is  a  salt  of  triphenylated  para- 
rosaniline,  and  is  made  by  the  action  of  a  large  excess  of  aniline  upon 
rosaniline.  If  magenta  is  used  instead  of  rosaniline  a  reddish-blue  is 
obtained. 

Diphenylamine  Blue  (spirit  soluble)  is  probably  the  chlorhydrate  of 
triphenylated  para-rosaniline,  and  is  made,  as  the  name  indicates,  from 
diphenylamine,  which  is  heated  with  oxalic  acid  to  120°  to  130°  C. 

Alkali  Blue  (Nicholson's  Blue,  Soluble  Blue)  is  the  sodium  salt  of 
the  mono-sulphonic  acid  of  a  spirit  soluble  blue,  and  is  made  by  sulpho- 
nating  the  latter. 

Patent  Blue  is  the  disulpho  salt  of  m-oxymalachite  green.  It  colors 
wool  a  very  fast  greenish-blue  and  resists  alkalies.  Is  much  used  as  a 
substitute  for  indigo  carmine. 

Hofmann's  Violets  consist  of  salts  of  the  ethyl  and  methyl  derivatives 
of  rosaniline  and  pararosaniline,  and  are  made  by  the  action  of  methyl 
or  ethyl  chloride  or  iodide  upon  magenta  in  the  presence  of  caustic  soda. 
It  is  of  historic  interest,  but  has  been  replaced  almost  completely  by 
methyl  violet. 

Methyl  Violet  is  a  salt  of  pentamethyl  pararosaniline,  and  is  pro- 
duced by  the  direct  oxidation  of  the  purest  dimethylaniline  with  copper 
chloride. 

Crystal  Violet  is  the  chlorhydrate  of  hexa  methyl  pararosaniline. 

Methyl  Green. — This  dye  is  formed  by  the  action  of  methyl  chloride 
upon  methyl  violet.  The  commercial  dye  is  the  zinc  double  chloride. 


458  THE  ARTIFICIAL  COLORING  MATTERS. 

(b)  DIPHENYL-METHANE  DYES. — Auramino,  an  important  yellow  dye, 
is  prepared  by  heating  tetramethyl  diamido  diphenylmethane  with  sul- 
phur, ammonium  chloride  and  common  salt  in  a  current  of  ammonia 
gas. 

Pyronine  is  a  red  dye  obtained  by  condensing  formaldehyde  with 
dimethyl-m-amidophenol  and  oxidizing  the  product. 

(c)  AZINES    (EURHODINES   AND    SAFRANiNEs). — Chromophor   group 
=  N —  N  =.    Neutral  Red  (Toluylen  Red)  is  a  basic  dye-color  prepared 
by  the  action  of  nitroso-dimethyl-aniline  upon  w-toluylen-diamine.     It 
is  used  with  cotton  after  mordanting  with  tannic  acid  and  tartar  emetic. 

Safranine  (Aniline  Rose)  is  prepared  by  the  oxidation  of  amido- 
azotoluene  and  toluidine,  or  of  p-tbluylen-diamine,  ortho-toluidine,  and 
aniline.  The  commercial  salt  is  the  chlorhydrate  of  the  safranine  base. 

Naphthalene  Red  (Magdala  Red)  is  the  compound  in  the  naphtha- 
lene series  corresponding  to  the  preceding.  It  is  obtained  by  fusing  the 
chlorhydrate  of  a-naphthylen-diamine,  a-naphthylamine,  and  amidoazo- 
naphthalene.  It  forms  a  dark-brown  powder,  soluble  in  alcohol  with 
strong  red  fluorescence.  It  is  used  largely  in  silk-dyeing  and  for  velvet 
because  of  its  fine  color  and  fluorescence. 

Mauve'in  (Perkin's  Violet)  is  of  historic  interest  mainly  as  the  first 
aniline  color.  It  was  obtained  by  W.  II.  Perkin  in  1856  by  the  oxidation 
with  sulphuric  acid  and  bichromate  of  potash  of  a  mixture  of  aniline 
and  toluidine. 

Methylene  Violet  is  a  reddish-violet  dye  obtained  by  the  action  of 
hydrochloride  of  nitroso-dimethyl-aniline  upon  a  mixture  of  the  hydro- 
chlorides  of  m-  and  p-xylidine. 

Indoines  are  basic  coloring  matters  dyeing  cotton  deep  shades  from 
dark  violet  to  indigo-blue,  fairly  fast  to  light  and  washing.  They  are 
made  by  combining  diazotized  safranines  with  a-  and  /?-naphthol  and 
conversion  into  hydrochlorides. 

(d)  INDULINES  AND  NIGROSINE. — Induline,  spirit  soluble   ( Coupler's 
Blue,  Guernsey  Blue,  etc.)  is  prepared  by  heating  amidoazobenzene  with 
aniline  to  160°  C. 

Induline,  water  soluble  (Indigo  substitute),  is  the  sodium  salt  of 
the  disulphonate  of  the  preceding,  and  is  extensively  used  for  silk  and 
wool. 

Paraphenylene  Blue  is  a  dark  blue  dye  of  the  induline  class  obtained 
by  the  action  of  p-phenylene-diamine  upon  hydrochloride  of  amidoazo- 
benzene. 

Naphthyl  Blue  is  the  sodium  sulphonate  of  anilido-phenyl-naphthin- 
duline.  Dyes  silk  blue  with  a  red  fluorescence,  and  is  faster  to  light 
than  the  ordinary  indulines. 

Nigrosine  is  prepared  by  heating  nitrophenol  with  aniline  and  aniline 
chlorhydrate.  The  alcohol  soluble  compound  is  the  simple  salt  of  the 
base,  while  the  sodium  sulphonate  forms  the  water  soluble  compound. 

(e)  ANILINE  BLACK. — For  the  preparation  of  aniline  black,  aniline 
chlorhydrate  is  very  carefully  oxidized.     The  dyestuff  is  not  prepared 
for  dyeing  or  printing,  but  is  fixed  on  the  fibre  by  an  oxidation  process 


PRODUCTS.  459 

which  develops  it  gradually.  It  is  a  very  fast  black.  Quite  a  variety 
of  oxidizing  agents  may  be  used.  Potassium  chlorate  and  copper  sul- 
phate are  frequently  used  in  admixture,  and  vanadate  of  ammonia  is  also 
of  special  serviceableness  in  connection  with  the  chlorate.  Electrolysis 
of  a  concentrated  solution  of  an  aniline  salt  will  also  produce  aniline 
black. 

2.  PHENOL  DYE-COLORS. 

(a)  NITRO-DERIVATIVES. — Picric  Acid  (Trinitrophenol)  is  made  by 
nitrating  carbolic  acid  direct  with  strong  nitric  acid,  or,  better,  by 
acting  upon  phenol-sulphonic  acid  with  strong  nitric  acid.  Forms  light 
yellow  leaflets  or  scales,  and  has  been  used  as  a  dye  for  silk  and  wool. 

Naphthol  Yellow  (Martius  Yellow,  Manchester  Yellow,  etc.)  is  the 
sodium,  potassium,  or  calcium  salt  of  dinitro-a-naphthol,  and  is  prepared 
by  the  nitration  of  a-naphthol  either  directly,  or  after  conversion  into 
the  mono-sulphonic  acid. 

Naphthol  Yellow  8  is  &  sulphonate  of  the  preceding,  and  is  made  by 
nitrating  the  a-naphthol-trisulphonic  acid.  The  color  is  faster  than 
picric  acid  or  the  simple  naphthol  yellow  and  is  more  extensively  used. 

Aurantia  is  the  ammonium  salt  of  hexa-nitro-diphenylamine,  and  is 
made  by  the  nitration  of  diphenylamine.  It  was  formerly  used  for 
wool  and  silk,  but  is  now  used  only  for  leather  coloring. 

(6)  ROSOLIC  ACIDS. — Eosolic  Acid  and  Aurin  (Pararosolic  Acid) 
may  be  prepared  from  rosaniline  and  pararosaniline  respectively  by 
treatment  with  sodium  nitrite  followed  by  boiling  in  the  presence  of  sul- 
phuric acid.  These  two  coloring  matters  are  no  longer  of  commercial 
importance. 

Yellow  Corallin  is  prepared  by  heating  pure  phenol  with  concen- 
trated sulphuric  acid  and  oxalic  acid  for  some  hours  until  the  evolution 
of  gas  nearly  ceases.  The  crude  product  of  the  reaction  obtained  by 
pouring  the  melted  mass  into  water  is  changed  into  the  commercial  dye 
by  dissolving  it  in  caustic  soda  solution  and  evaporation  to  dryness. 

Red  Corallin  (Paeonin)  is  obtained  by  the  action  of  ammonia  under 
pressure  upon  the  yellow  corallin,  and  represents  an  intermediate  pro- 
duct between  aurin  and  para-rosaniline. 

(c)  PHTHALEINS. — Phenol-phthalein  is  not  used  as  a  dyestuff,  but  as 
an  indicator  in  alkalimetry. 

Fluorescein  (Resorcin  Phthalein)  is  made  by  heating  molecular  pro- 
portions of  resorcin  and  phthalic  anhydride  to  195°  to  200°.  Fluor- 
escein is  not  used  as  such  for  dyeing,  but  is  converted  into  the  eosins. 
The  sodium  salt  of  the  fluorescein  comes  into  commerce  under  the  name 
of  uranine. 

Eosins. — The  several  halogen  substitution  derivatives  of  fluorescein 
form  the  class  of  dyes  known  as  eosins.  Thus,  the  potassium  or  sodium 
salt  of  tetrabrom-fluorescein  is  the  eosin  yellow  shade,  while  the  cor- 
responding salts  of  tetraiodo-fluorescein  constitute  eosin  blue  shade. 
Methyl  and  Ethyl  Eosin  (Primrose)  are  the  methyl  and  ethyl  ethers  of 
tetrabrom-fluorescein.  Aureosin  is  a  chlorinated  fluorescein.  Saffrosine 
is  the  potassium  or  sodium  salt  of  dibrom-dinitrofluorescein.  Erythrosin 


460  THE  ARTIFICIAL  COLORING  MATTERS. 

is  the  potassium  salt  of  di-iodo-fluorescein.  Rose  Bengale  is  the  sodium 
salt  of  tetraiododichlor-fluorescein.  Phloxin  is  the  potassium  salt  of 
tetrabromdichlor-fluorescein,  and  Cyanosine  is  the  potassium  salt  of  'the 
methyl  ether  of  phloxin.  Rhodamine  is  the  phthalein  of  diethyl-meta- 
amidophenol.  Cyclamine  is  obtained  by  the  action  of  iodine  upon  thi- 
onated  dichlorfluorescein.  Violamine  is  obtained  by  the  action  of  o-tolui- 
dine  upon  fluorescein  chloride  and  sulphonation  of  the  product.  Wool 
and  silk  especially  are  dyed  with  the  eosins,  and  cotton  after  mordanting 
with  various  metallic  salts. 

Gallein  is  the  phthalein  of  pyrogallol,  and  is  prepared  by  an  analo- 
gous method  to  that  described  under  fluoreseein.  It  is  very  little  used 
in  dyeing,  but  serves  for  the  preparation  of 

Ccerulein. — This  dye  is  obtained  by  heating  gallein  with  twenty  times 
its  weight  of  strong  sulphuric  acid.  Forms  a  dark  amorphous  mass, 
which  dissolves  in  alkalies  with  a  beautiful  green  color.  Coerulein 
forms  a  colorless  compound  with  sodium  bisulphite,  which  is  known  as 
Ccerulein  8,  and  is  much  used  in  dyeing,  as  it  is  easily  decomposed  by 
steaming. 

3.    NlTROSO  AND  OXYAZINE  COLORS. 

(a)  NITROSO  COLORS  (Chromophor  group  =  N —  OH). — Gambine  is 
obtained  by  the  action  of  nitrous  acid  upon  a-naphthol.  It  dyes  iron- 
mordanted  fabrics  green. 

Dinitrosoresorcin  is  obtained  by  the  action  of  nitrous  acid  upon 
resorcin.  Dyes  like  the  previous  color. 

Dioxine  is  obtained  by  the  action  of  nitrous  acid  upon  dioxynaph- 
thalene.  Dyes  bright  green  or  brown  shades  on  metallic  mordants. 

(&)   INDOPHENOLS  AND  INDAMINE     (    Chromophor,  N  =  0  ). — Indo- 

V  U__J    ' 

phenol  (a-Naphthol  Blue)  is  prepared  by  oxidizing  dimethyl-parapheny- 
lene-diamine  and  a-naphthol  with  bichromate  of  potash  and  acetic  acid 
Indophenol  may  be  reduced  by  glucose  and  caustic  soda  to  a  leuco- 
compound  known  as  Indophenol  white,  which  is  also  sold  commercially. 
When  cotton  goods  are  printed  with  leuco-indophenol,  the  blue  color 
may  be  developed  in  dilute  bichromate  of  potash  solution. 

Indamines  are  obtained  by  heating  the  indulines  with  p-phenylene: 
diamine  and  p-phenylene-diamine  hydrochloride.  Dyes  deep  indigo- 
blue  shades  on  cotton  mordanted  with  tannin  and  tartar  emetic. 


(c)    OXYAZINES  I  Chromophor     <^     ^>  j. — Azurine   is   obtained   by 

V  x(y    / 

the   action   of   nitrosodimethyl-aniline   hydrochloride   upon   si/m-dioxy- 
benzoic  acid.    Dyes  a  violet  blue  on  chrome-mordanted  wool  or  cotton. 

Gallocyanine  is  obtained  by  the  action  of  nitrosodimethyl-aniline  upon 
gallic  acid.  It  is  a  gray  paste,  insoluble  in  water,  but  soluble  in  alcohol 
with  bluish-violet  color. 

Prune  Pure  is  the  methyl-ether  of  gallocyanine. 

Gallanilic  Indigo  is  the  sodium  bisulphite  compound  of  gallocyanine- 
anhydride-anilide. 

Meldola's  Blue  is  obtained  by  the  action  of  nitrosodimethyl-aniline 


PRODUCTS.  461 

hydrochloride  upon  /3-naphthol.  Dyes  cotton  mordanted  with  tannin  and 
tartar  emetic  indigo-blue. 

Nile  Blue,  Capri  Blue,  and  Gallamine  Blue  are  all  oxyazine  colors 
obtained  by  analogous  reactions  of  nitrosodimethyl-aniline  or  the  cor- 
responding amidophenol. 

Resorcin  Blue.  —  By  the  action  of  nitrous  acid  upon  resorcin  is  pro- 
duced diazoresorcin,  which  by  the  action  of  concentrated  sulphuric  acid 
is  changed  into  diazoresorufin.  This  yields  a  hexabrom-derivative,  the 
ammonium  salt  of  which  is  the  commercial  dye.  It  is  used  for  dyeing 
silk  and  wool  a  blue  color,  which  has  a  red  fluorescence,  especially  by 
artificial  light.  By  combining  with  yellow  dyes  it  yields  a  fluorescent 
olive  color. 

(d)  THIAZINES       Chromophor  <N   .—Methylene  Blue  is  prepared 


by  oxidizing  dimethyl-p-phenylenediamine  and  dimethyl-aniline  in 
the  presence  of  sodium  thiosulphate  and  zinc  chloride.  The  commercial 
salt  is  a  zinc  double  chloride  of  the  sulphur  base,  called  tetra-methyl- 
thionin. 

4.  Azo  DYE-COLORS.  —  Chromophor  group,  —  N  =  N  —  . 

A.  MONOAZO  DYES.  —  (a)  Amidoazo  Dyes. 

Chrysoidine  (Diamidoazobenzene  Hydrochloride)  is  obtained  by  ad- 
mixing solutions  of  diazobenzene  hydrochloride  and  m-phenylene-dia- 
mine.  Forms  reddish-brown  crystals.  Its  solution  absorbs  actinic  rays. 

Phenylene  Brown  (Vesuvine)  is  triamido-azobenzene  hydrochloride. 
Forms  a  brown  powder  soluble  in  water. 

Butter  Yellow  is  dimethylamidoazobenzene.  This  yellow  dye  is  sol- 
uble in  oils  and  is  much  employed  for  coloring  butter,  oils,  etc. 

Acid  Yellow  (Fast  Yellow)  is  the  sodium  salt  of  the  disulphonic  acid 
of  aniline  yellow  (amidoazobenzene).  It  is  used  largely  in  dyeing  com- 
pound shades. 

Dimethyl-aniline  Orange  (Helianthin)  is  the  ammonia  salt  of  di- 
methyl-aniline-azobenzene-sulphonic  acid.  Dyes  silk  and  wool  a  fiery 
orange.  It  is  also  used  as  an  indicator  in  alkalimetry,  as  the  light 
yellow  color  of  the  solution  is  immediately  turned  red  by  the  addition 
of  a  drop  of  hydrochloric  acid. 

Diphenylamine  Orange  (Tropaeolin  00,  Orange  IV)  is  formed  by 
the  action  of  diazobenzene-sulphonic  acid  upon  diphenylamine.  Dyes 
silk  or  wool  a  very  fine  golden  yellow. 

Metanil  Yellow  is  the  sodium  salt  of  phenylamidoazobenzene-w-sul- 
phonic  acid.  Forms  a  yellow  soluble  powder. 

Archil  substitute  (naphthion  red)  is  made  by  combining  p-nitrani- 
line  with  naphthionic  acid  or  /2-naphthylamine-sulphonic  acid. 

(6)  Oxyazo  Dyes.  —  Sudan  G  (Aniline-azorescorcin)  is  a  brown 
powder  hardly  soluble  in  water,  soluble  in  alcohol.  It  is  used  for  color- 
ing spirit  varnishes,  oils,  etc. 

Sudan  Brown  (Pigment  Brown)  is  made  by  the  action  of  hydro- 
chloride  of  a-diazonaphthalene  upon  a-naphthol.  It  is  used  for  coloring 
varnishes,  soaps. 

Carmine-naphte  is  an  isomeric  compound  formed  from  /3-diazonaph- 


462  THE  ARTIFICIAL  COLORING  MATTERS. 

thalene  and  /3-naphthol.     Forms  a  red-brown  powder,  soluble  in  sul- 
phuric acid  with  fuchsine-red  color. 

Alizarin  Yellow  is  a  yellowish-browTn  dye  made  by  combining 
p-nitraniline  with  salicylic  acid. 

Fast  Brown  N  (Naphthylamine  Brown)  is  made  by  combining  naph- 
thionic  acid  with  a-naphthol.  Dyes  wool  brown  from  an  acid  bath. 

Crocein  Orange  (Ponceau  4GB)  is  prepared  from  hydrochloride  of 
diazobenzene  and  /?-naphthol  monosulphonic  acid.  It  is  a  fiery  red  pow- 
der, dyeing  a  reddish  orange  on  wool. 

Orange  G  is  the  sodium  salt  of  diazobenzene-/?-naphthol-disulphonic 
acid.  It  dyes  an  orange-yellow  shade. 

Cochineal  Scarlet  2R  results  from  the  action  of  diazotoluene  upon 
a-naphthol-monosulphonic  acid.  It  forms  a  cinnabar-red  dye-color. 

Azococcin  2R  results  from  the  action  of  hydrochloride  of  diazoxy- 
lene  upon  a-naphthol-sulphonic  acid.  It  forms  a  red-brown  powder, 
difficultly  soluble  in  water.  It  is  used  in  silk  dyeing. 

Wool  Scarlet  R  results  from  the  action  of  hydrochloride  of  diazoxy- 
lene  upon  a-naphthol-disulphonic  acid.  It  forms  a  brown-red  powder, 
soluble  in  water  with  yellowish-red  color. 

Ponceau  2R  (Xylidine  Red)  results  from  the  action  of  hydrochloride 
of  diazo-m-xylene  upon  /?-naphthol-disulphonic  acid.  It  forms  a  red 
powder,  easily  soluble.  It  has  be^n  used  in  large  quantities  as  a  substi- 
tute for  cochineal. 

Ponceau  3R  (Cumidine  Red)  results  from  the  action  of  hydrochloride 
of  diazo-m-cumene  upon  /8-naphthol-disulphonic  acid.  It  is  used  as  the 
preceding,  but  gives  redder  shades. 

Anisol  Red  and  Phenetol  Red  are  formed  by  the  action  of  anisidine 
and  amido-phenetol  respectively  upon  /3-naphthol-disulphonic  acid. 

Fast  Red  B  (Bordeaux  B)  is  formed  by  the  action  of  hydrochloride 
of  diazonaphthalene  upon  /3-naphthol-disulphonic  acid. 

a-Naphthol  Orange  (Tropagolin  000,  No.  1)  is  the  sodium  salt  of  p- 
sulphanilic-acid-azo-a-naphthol.  Forms  orange-yellow  scales,  tolerably 
soluble  in  water.  It  dyes  silk  and  wool  a  reddish  orange. 

(3-Naphthol  Orange  (Tropaeolin  000,  No.  2,  Mandarin)  results  from 
the  action  of  p-diazobenzene-sulphonic  acid  upon  /?-naphthol  in  alkaline 
solution.  It  forms  an  orange-red  soluble  powder,  and  is  used  largely 
for  wool-dyeing. 

Fast  Red  A  (Rocelline,  Cerasine,  etc.)  is  prepared  by  uniting  a-diazo- 
naphthalene-sulphonic  acid  with  /?-naphthol.  It  forms  a  brown-red 
powder,  more  soluble  in  hot  than  in  cold  water.  It  is  used  largely  as  a 
substitute  for  barwood  and  orseille. 

Azorubin  S  (Fast  Red  C,  Carmoisin)  is  the  sodium  salt  of  the  disul- 
phonic  acid  of  naphthalene-azo-a-naphthol.  It  forms  a  reddish-brown 
soluble  powder. 

Brilliant  Ponceau  4R  (Cochineal  Red  A)  and  Fast  Red  D  (Amaranth) 
are  both  sodium  salts  of  trisulphonic  acids  of  naphthalene-azo-/?-naph- 
thol,  isomeric  with  each  other.  The  former  is  a  scarlet-red  easily  soluble 
powder,  the  latter  a  reddish-brown  powder. 


PRODUCTS.  463 

Roxamine  is  the  sodium  salt  of  dioxyazo-naphthalene-sulphonic  acid. 
It  dyes  wool  red  from  an  acid  bath  and  is  used  as  an  orchil  substitute. 

B.  DISAZO  DYES. — (a)  Disazo  Dyes  from  Azo  Dye-colors  (Primary 
Disazo  Dyes}. — Resorcin  Brown  is  the  sodium  salt  of  a  sulphonic  acid 
of  resorcin-disazo  xylene-benzene.  Forms  a  brown  soluble  powder. 

Fast  Broivn  results  from  the  action  of  two  molecules  of  a-diazo- 
naphthalene-sulphonic  acid  upon  one  molecule  of  resorcin. 

Acid  Brown  G  is  formed  by  the  action  of  hydrochloride  of  diazo- 
benzene  upon  chrysoidin-sulphonic  acid.  Dyes  wool  brown  in  acid 
solution. 

Bismarck  Brown  is  the  hydrochloride  of  benzene-disazo-phenylene- 
diamine.  It  is  much  used  in  coloring  leather. 

(&)  Disazo  Dyes  from  Amido-azo  Dyes  (Secondary  Disazo  Dyes}. — 
Cloth  Red  G  (Azococcin  7B)  results  from  the  action  of  diazoazo-benzene 
upon  a-naphthol-sulphonic  acid.  Forms  a  brown  powder  not  readily 
soluble  in  water.  Used  in  wool-dyeing,  either  alone  or  in  connection 
with  logwood,  fustic,  etc. 

Brilliant  Crocein  (Cotton  Scarlet)  results  from  the  action  of  hydro- 
chloride  of  diazoazo-benzene  upon  /8-naphthol-disulphonic  acid.  Forms 
a  reddish  soluble  powder. 

Biebrich  Scarlet  (Ponceau  B). — It  is  the  sodium  salt  of  amido-a^o- 
benzene-disulphonic-acid-azo-/3-naphthol.  Forms  a  brown-red  fairly 
soluble  powder.  Dyes  wool  and  silk  in  acid  bath  a  red  color  like  coch- 
ineal. 

Crocein  Scarlet  3B  (Ponceau  4RB)  results  from  the  action  of  diazo- 
azo-benzene-monosulphonic  acid  upon  /?-naphthol-monosulphonic  acid. 
Forms  a  red-brown  powder  dissolving  with  scarlet-red  color.  Used  in 
wool-  and  silk-dyeing. 

Bordeaux  G  is  obtained  by  the  action  of  amido-azo-toluene-mono- 
sulphonic  acid  upon  /3-naphthol-monosulphonic  acid  S.  Dyes  wool  red 
from  an  acid  bath. 

Naphthol  Black  is  the  sodium  salt  of  the  tetrasulphonic  acid  of  naph- 
thalene-disazo-naphthalene-/3-naphthol.  Forms  a  violet-black  powder. 
Used  exclusively  in  wool-dyeing. 

Wool  Black  is  the  sodium  salt  of  the  disulphonic  acid  of  a  benzene- 
disazo-benzene-p-tolyl-/?-naphthylamine.  It  forms  a  bluish-black  soluble 
powder.  Dyes  a  deep  blue-black  color  and  is  quite  stable. 

Naphthylamine  Black  and  Anthracite  Black  are  obtained  by  the  ac- 
tion of  disulpho-naphthylene-azo-a-naphthylamine  upon  a-naphthyla- 
mine  and  diphenyl-m-phenylene-diamine  respectively. 

Fast  Violet  is  the  sodium  salt  of  the  disulphonic  acid  of  a  naphtha- 
lene-disazo-benzene-/2-naphthol.  Forms  a  dark  brown  soluble  powder. 
Used  in  wool -dyeing. 

Chromatropes  2R,  2B,  6D,  etc.,  are  combinations  of  diazo  compounds 
with  dioxy-naphthalene-disulphonic  acid.  They  give  colors  varying  from 
scarlet  to  magenta,  which  on  subsequent  treatment  with  a  boiling  solu- 
tion of  potassium  bichromate  change  to  very  fast  blacks. 

(c)  Disazo  Dyes  from  Diamido  Compounds  (Congo  Group,  or  Ben- 


464  THE  ARTIFICIAL  COLORING  MATTERS. 

zidine  Dyes). — These  dyes  are  distinguished  from  all  other  coal-tar  dyes 
by  the  readiness  with  which  vegetable  fibres  may  be  dyed  with  them 
without  previous  mordanting,  so  that  they  are  equally  applicable  to  vege- 
table or  animal  fibres,  and  can  be  used  with  goods  of  mixed  fibre.  They 
are  often  called  substantive  cotton  dyes.  Their  affinity  for  the  fibres 
indeed  goes  so  far  that  they  can  be  used  like  mordants  to  facilitate  the 
fastening  of  other  coal-tar  dyes  upon  the  vegetable  fibres. 

The  commercial  products  consist  generally  of  the  potassium,  sodium, 
or  ammonium  sulphonates  of  the  dye-color. 

Naphthalene  Red  is  the  sodium  salt  of  naphthalene-disazo-binaph- 
thionic  acid.  Dyes  unmordanted  cotton  red  from  a  boiling  alkaline  bath. 

Diamine  Gold  is  the  sodium  -salt  of  disulpho-naphthalene-disazo- 
biphenetol.  It  dyes  unmordanted  cotton  yellow. 

Chyrsophenine  is  the  sodium  salt  of  disulpho-stilbene-disazo-biphene- 
tol.  Dyes  like  the  previous  color. 

By  the  diazotizing  of  this  same  diamido-stilbene-disulphonic  acid  are 
also  derived  Hessian  Yellow,  Hessian  Purple  N  and  B,  and  Hessian 
Violet. 

The  diazo  compound  from  the  molecule  of  benzidine  is  similarly 
combined  with  a  series  of  compounds  to  produce  the  well-known  ben- 
zidine dyes  Congo  G  and  P,  Congo  Yellow,  Sulphanil  Yellow,  Brilliant 
Congo  G,  Cloth  Brown,  Diamine  Black,  Diamine  Blue,  Diamine  Scarlet, 
Diamine  Brown,  Diamine  Green,  and  Congo  Corinth  G. 

Congo  Red  is  the  sodium  salt  of  diphenyl-p-disazo-naphthionic  acid. 
Forms  a  reddish-brown  powder,  soluble  in  water  with  fine  red  color. 
This  solution  is  so  sensitive  to  acids  that  a  single  drop  of  very  dilute 
sulphuric  acid  suffices  to  convert  the  whole  of  the  liquid  to  a  beautiful 
blue.  It  is  therefore  a  valuable  indicator  in  volumetric  analysis. 

Benzopurpurin  is  formed  by  the  action  of  tetrazo-ditolyl  chloride 
upon  naphthylamine  sulphonate  of  soda.  It  is  a  dark  red  powder,  dis- 
solving easily  in  water.  The  scarlet  obtained  from  this  dye  is  not 
changed  by  dilute  acid  as  is  that  from  Congo  red. 

Azo  Blue  is  formed  by  the  action  of  tetrazo-ditolyl  chloride  upon  /?- 
naphthol-sulphonate  of  potash.  It  is  a  dark  blue  powder,  dissolving 
easily  in  water.  It  is  fast  to  acids  but  not  to  light. 

Diazotized  tolidine  yields,  besides  the  two  dyes  last  mentioned, 
Delta-purpurin  5B,  Chrysamine,  Azo  Blue,  and  Azo  Mauve.  Dianisi- 
dine  and  diphenetidine  also  yield,  when  diazotized,  well-known  dyes  of 
this  class,  such  as  Benzoaurine,  Heliotrope,  and  Benzo-indi 'go-blue. 

Carbazol  Yellow  and  Naphthol  Blue-black  are  also  colors  of  this  class. 

Supplementary  to  the  Azo  Dyes. — Tartrazin  is  formed  by  the  action 
of  two  molecules  of  phenyl-hydrazin-p-sulphonic  acid  upon  one  mole- 
cule of  dioxytartaric  acid.  Orange-yellow  powder,  easily  soluble  in 
water.  It  is  a  valuable  woollen  dye,  very  fast  to  light  and  fulling. 

Primuline  and  Ingrain  Colors. — Primuline  is  mentioned  here  because 
of  its  ready  convertibility  into  azo  colors  (ingrain  colors).  It  is  the 
sodium  salt  of  the  sulpho-  acid  of  a  sulphated  amido-  compound,  and  is 
formed  by  the  action  of  sulphur  upon  p-toluidine.  The  primuline  base 


PRODUCTS.  465 

is  a  yellow  powder,  very  soluble  in  hot  water,  and  dyes  unmordanted 
cotton  direct  from  a  neutral  or  alkaline  bath.  Its  great  importance, 
however,  lies  in  the  fact  that  as  the  sulpho-  acid  of  a  primary  amine  it 
can  be  diazotized  (see  p.  446),  and  then  is  capable  of  combining  with 
the  whole  range  of  phenols  and  amines  to  form  azo  colors.  These  opera- 
tions can  readily  be  carried  out  upon  the  fibre,  whence  the  colors  so 
obtained  have  been  called  ingrain  colors.  This  diazotizing  and  develop- 
ing with  the  phenol  or  amine  may  be  effected  upon  silk,  wool,  or  cotton 
fibre  previously  dyed  with  the  primuline  base.  In  this  way  yellows, 
oranges,  purples,  reds,  scarlets,  maroons,  and  browns  are  produced. 

When  paranitraniline  is  diazotized  we  obtain  azo-p-nitraniline.  If 
sulphuric  acid  is  added  to  the  compound  so  formed  and  the  diazo  com- 
pound admixed  with  a  large  excess  of  salt,  the  sodium  sulphate  so 
produced  protects  the  diazo  compound  from  light,  even  in  the  dry 
state,  until  ready  for  use  in  the  dye-bath  for  dyeing  goods  padded  with 
naphthols,  naphthylamines,  etc. 

5.  QUINOLINE  AND  AcRiDiN  DYES. — Quinoline  Yellow  is  the  sodium 
salt  of  quinoline-phthalon-sulphonic  acid.     It  forms  a  yellow  powder, 
soluble  in  water  or  alcohol  with  yellow  color.    Used  for  wool-  and  silk- 
dyeing. 

Flavaniline  is  obtained  by  heating  acetanilid  with  anhydrous  zinc 
chloride  for  several  hours  to  250°  C.  The  commercial  salt  is  the  hydro- 
chloride  of  the  base  so  obtained.  "Was  formerly  used  for  wool-  and  silk- 
dyeing  and  for  cotton  after  mordanting  with  tannin  and  tartar  emetic. 

Cyanine  (Quinoline  Blue)  is  prepared  by  treating  a  mixture  of  qui- 
noline  and  lepidine  with  amyl  iodide.  It  forms  a  fine  blue  color,  but 
unstable  to  light.  It  is  not  of  importance  in  textile  coloring,  but  is  used 
in  the  manufacture  of  orthochromatic  photographic  dry  plates. 

Quinoline  Red  is  obtained  by  the  action  of  benzo-trichloride  upon  a 
mixture  of  quinaldine  and  isoquinoline.  Is  also  employed  in  the  manu- 
facture of  orthochromatic  photographic  plates. 

Acridine  Yellow  is  the  hydrochloride  of  diamido-dimethyl-acridine. 
Dyes  silk  greenish-yellow  with  green  fluorescence,  and  cotton  mordanted 
with  tannin  yellow. 

Phosphine  (Chrysaniline)  is,  as  was  before  noted  (see  p.  457),  a  by- 
product in  the  manufacture  of  magenta,  but  is  probably  diamido-phenyl- 
acridine.  The  phosphine  of  commerce  is  the  nitrate  or  chlorhydrate  of 
the  base  chrysaniline.  Used  at  present  chiefly  in  silk-dyeing. 

6.  ARTIFICIAL  INDIGO. — Artificial  indigo  is  now  an  extensive  article 
of  commerce,  and  in  purity  and  uniformity  distinctly  excels  the  natural 
product.    The  first  important  synthesis  was  that  utilizing  what  is  known 
as  "propiolic  paste,"  which  is  a  moist  paste  containing  a  definite  per- 
centage  (usually  twenty -five  per  cent.)   of  o-nitrophenyl-propiolic  acid 
prepared  from  synthetic  cinnamic  acid.     Professor  Baeyer  found  that 
this  o-nitrophenyl-propiolic  acid  when  in  alkaline  solution  is  readily 
changed  by  reducing  agents,  like  grape-sugar,  milk-sugar,  sulphides,  sul- 
phydrates,  and  especially  by  xanthogenate,  into  indigo-blue.     The  re- 
ducing agents  act  already  in  the  cold  in  either  aqueous  or  alcoholic  solu- 

30 


466  THE  ARTIFICIAL  COLORING  MATTERS. 

tions.  This  "propiolic  paste"  was  used  for  a  time  in  calico-printing, 
being  printed  on  the  goods  along  with  the  reducing  agent,  but  the  decom- 
position of  the  xanthogenate  of  soda  develops  mercaptan,  the  unpleasant 
odor  of  which  adheres  very  persistently  to  the  goods,  and  the  blue  color 
is  slightly  gray  in  shade.  It  has  therefore  been  given  up  for  the  present. 

Kalle's  artificial  indigo  (due  to  Baeyer  in  conjunction  with  Drewsen) 
is  prepared  by  converting  o-nitrobenzaldehyde  into  o-nitrophenyllacto- 
ketone  by  the  action  of  acetone.  The  product  of  the  reaction  is  then 
changed  to  a  soluble  compound  by  treatment  with  sodium  bisulphite, 
and  is  sold  under  the  name  of  ''indigo  salt."  This  salt,  if  dissolved  in 
water  or  thickened  with  any  suitable  substance  and  afterwards  applied 
to  woollen  fabrics  and  these  passed  through  a  solution  of  caustic  soda 
of  20°  B.,  causes  the  full  color  of  indigo  to  develop. 

The  o-nitrobenzaldehyde  can  be  made  from  o-nitrotoluene  by  direct 
oxidation  with  manganese  dioxide  and  sulphuric  acid.  Considerable  in- 
digo is  made  this  way  at  present,  but  the  amount  of  toluene  available  is 
not  sufficient  to  allow  of  its  replacing  the  whole  of  the  natural  indigo. 

Following  these  syntheses  comes  that  of  Heumann  from  phenyl-glyco- 
coll,  which,  when  fused  with  caustic  alkali,  yields  pseudo-indoxyl,  and 
this  is  easily  changed  into  indigo  by  atmospheric  oxidation. 

Similarly,  phenyl-glycocoll-o-carboxylic  acid  (from  chloracetic  and 
anthranilic  acids),  heated  with  caustic  alkalies,  yields  the  same  results. 

The  method  of  Heumann  was,  however,  not  commercial  until  a  cheap 
production  of  phenylglycine-o-carboxylic  acid  was  devised  by  the  Bad- 
ische  Aniline  and  Soda  Fabrik.  The  starting  point  in  this  is  naphtha- 
lene, a  cheap  and  abundant  product  of  coal-tar.  Naphthalene  on  treat- 
ment with  strong  sulphuric  acid  and  mercury  is  converted  into  phthalic 
anhydride.  From  phthalic  anhydride  phthalamide  is  produced  by  the 
action  of  ammonia  and  from  this  anthranilic  acid  is  formed  by  the  action 
of  chlorine  and  caustic  soda.  Anthranilic  acid  and  chloracetic  acid  then 
react  to  form  phenylglycine-o-carboxylic  acid,  which  by  heating  with 
caustic  soda  is  converted  into  indigo,  or  rather  into  indoxyl-carboxylic 
acid,  the  alkaline  solution  of  which  is  changed  by  atmospheric  oxidation 
finally  into  indigo.  This  artificial  indigo  of  the  Badische  Co.  is  known 
as  indigo  pure,  and  usually  occurs  as  a  paste  containing  twenty  per  cent. 
of  indigo  suspended  in  water. 


7.  OXYKETONE  COLORS  (  Chromophor        ||       I . 

V  — c— / 


(a)  ANTHRAQUINONE  DERIVATIVES. — Alizarin. — This  term  may  be 
applied  commercially  to  the  pure  dioxyanthraquinone  found  in  the 
madder-root  and  made  artificially  from  anthraquinone-monosulphonic 
acid,  or  to  the  two  trioxyanthraquinones  obtained  from  anthraquinone- 
disulphonic  acid,  and  known  more  accurately  as  anthrapurpurin  and 
flavopurpurin.  The  first  or  true  alizarin  is  the  blue  shade  alizarin.  This 
is  a  yellow  powder  coming  into  commerce  as  a  ten  per  cent,  or  twenty 
per  cent,  paste.  When  dried  and  sublimed  it  forms  splendid  orange-red 
crystals,  melting  at  280°  C.  It  is  insoluble  in  water  and  sparingly  sol- 


PRODUCTS.  467 

uble  only  in  cold  alcohol.  Sulphuric  acid  dissolves  it,  and  on  diluting 
the  alizarin  is  precipitated  again  unchanged.  It  acts  as  a  weak  acid, 
and  forms  alizarates  with  the  alkalies  and  metallic  hydroxides. 

Quinizarin,  which  is  made  by  the  condensation  of  phthalic  anhy- 
dride with  hydroquinone,  is  an  isomer  of  alizarin  and  is  a  dioxyanthra- 
quinone.  Both  alizarin  and  quinizarin  yield  purpurin  or  trioxyan- 
thraquinone  on  oxidation.  Quinizarin  is  of  no  importance  as  a  dyestuff 
by  itself,  but  is  converted  into  valuable  acid  dyestuffs  on  condensation 
with  primary  aromatic  amines  and  subsequent  sulphonation.  Such  dye- 
stuffs  are  alizarin  cyanine  green  and  alizarin  pure  blue. 

Anthrarufin  is  also  an  isomer  of  alizarin.  It  is  the  parent  sub- 
stance of  the  important  blue  acid  wool  dye  alizarin  saphirol,  which  is 
probably  diamidoanthrarufin-disulphonic  acid. 

Anthr  a  purpurin  (Isopurpurin),  as  before  stated,  is  a  trioxyanthra- 
quinone,  but  is  generally  produced  along  with  the  preceding  compound 
in  the  manufacture  of  commercial  alizarin,  as  both  the  mono-sulphonic 
and  the  disulphonic  acids  are  obtained  in  sulphonating  anthraquinone. 
Anthrapurpurin  is  obtained  in  the  purest  state  by  melting  pure 
/3-anthraquinone-disulphonic  acid  with  caustic  soda  and  chlorate  of 
potash.  It  melts  at  360°  C. 

Flavopurpurin  is  obtained  also  in  the  manufacture  of  commercial 
alizarin,  and  can  be  prepared  as  sole  product  by  melting  a-anthra- 
quinone-disulphonic  acid  with  caustic  soda  and  chlorate  of  potash. 
Forms  orange-colored  needles,  melting  at  over  300°  C.  A  mixture  of 
anthrapurpurin  and  flavopurpurin  with  little  alizarin  constitutes  the 
commercial  yellow  shade  alizarin. 

Purpurin  is  also  a  trioxyanthraquinone,  but  differs  in  its  molecular 
formula  from  both  anthrapurpurin  and  flavopurpurin,  and  is  there- 
fore one  of  three  isomers.  It  is  not  a  constituent  of  commercial  artificial 
alizarin,  but  is  found  accompanying  true  alizarin  in  the  madder-root. 
It  forms  red  needles,  beginning  to  sublime  at  150°  C.  and  melting  at 
253°  C.  It  is  soluble  in  boiling  water  with  dark-red  color. 

Alizarin  Bordeaux  B  is  a  tetraoxyanthraquinone,  and  is  made  by 
oxidizing  alizarin  with  fuming  sulphuric  acid  and  saponification  of  the 
ether  so  formed. 

Alizarin  Cyanine  R  is  penta-oxyanthraquinone  obtained  by  oxidizing 
the  alizarin  bordeaux  in  sulphuric  acid  with  manganese  dioxide  and 
heating  the  intermediate  sulphuric  ether  with  dilute  acid.  Dyes  wool 
mordanted  with  alumina  violet,  with  chromium  blue. 

Alizarin  Orange  (Nitroalizarin)  is  formed  from  alizarin  by  the 
action  of  nitrous  acid,  or  by  the  action  of  nitric  acid  of  42°  B.  upon 
alizarin  suspended  in  glacial  acetic  acid.  It  forms  a  yellow  paste  of 
twenty  per  cent,  dry  material.  Aluminum  salts  form  an  orange  color, 
chromium  salts  a  brown-red  shade.  Used  with  silk,  wool,  and  cotton. 

Alizarin  Red  is  the  sodium  salt  of  alizarin-monosulphonic  acid,  and 
Alizarin  Maroon  is  amidoalizarin. 

Alizarin  Blue  is  a  dioxyanthraquinone-quinoline,  and  is  made  by 
heating  /?-nitroalizarin  with  glycerine  and  sulphuric  acid  to  90°  C. 


468  THE  ARTIFICIAL  COLORING  MATTERS. 

Dark  blue  powder,  almost  insoluble  in  water.  Hence  is  used  either  by 
reduction  with  zinc-dust,  grape-sugar,  or  similar  reducing  agent  and 
subsequent  atmospheric  oxidation,  as  in  indigo-dyeing,  or  by  forming 
a  soluble  compound  with  alkaline  bisulphites,  designated  as  Alizarin 
Blue  8.  This  latter  is  much  faster  to  light  than  the  original  color. 

Alizarin  Indigo-Hue  8  and  Alizarin  Green  8  are  similar  sodium  bi- 
sulphite compounds, — the  first  of  penta-oxyanthraquinone-quinoline  and 
the  second  of  tri-  and  tetra-oxyanthraquinone-quinoline  and  their  sul- 
phonic  acids. 

Anthracene  Brown  (Anthragallol)  is  a  trioxyanthraquinone.  It  is 
formed  by  heating  benzoic  and  gallic  acids  with  concentrated  sulphuric 
acid,  or  by  heating  pyrogallol  with  phthalic  anhydride  and  zinc  chloride. 
It  comes  into  commerce  as  a  dark  brown  paste,  and  yields  very  fast 
shades. 

Riiffigallol  is  a  hexaoxyanthraquinone,  and  is  made  by  the  action  of 
sulphuric  acid  upon  gallic  acid. 

Indanthrene  X  is  obtained  by  fusing  /3-amidoanthraquinone  with 
caustic  potash.  It  dyes  cotton  from  a  reduced  vat  (like  indigo)  bright 
blue  shades  which  are  extremely  fast  to  light. 

(&)    OXYKETONE  COLORS  OTHER  THAN  ANTHRAQUINONE  DERIVATIVES. — 

Alizarin  Yellow  A  is  made  by  the  condensation  of  benzoic  acid  with 
pyrogallol,  and  is  a  trioxybenzophenone,  while  Alizarin  Yellow  C  is 
made  by  the  condensation  of  acetic  acid  with  pyrogallol  in  the  pres- 
ence of  zinc  chloride.  It  is  a  gallacetophenone. 

Anthracene  Yellow  is  obtained  by  the  treatment  of  dioxy-/?-methyl- 
coumarin  writh  bromine. 

Alizarin  Black  8  is  the  sodium  bisulphite  compound  of  naphthazar- 
ine  ( dioxynaphthoquinone ) . 

Galloflavin  is  formed  by  the  atmospheric  oxidation  of  gallic  acid  in 
alkaline  solution.  Forms  a  dirty-yellow  paste,  insoluble  in  water  or 
hydrochloric  acid.  Wool  mordanted  with  chromium  salts  takes  a  color 
resembling  that  obtained  from  fustic. 

8.  THE  SULPHUR  OR  SULPHIDE  COLORS. 

Cachou  de  Laval  was  obtained  already  in  1873  by  the  fusion  of 
organic  substances  such  as  sawdust,  bran,  etc.,  with  sodium  sulphide. 
It  dyes  cotton  brown. 

The  fact  that  diphenylamine  and  its  derivatives  fused  with  sulphur 
and  sodium  sulphide  yielded  a  series  of  colors  has  been  utilized  in  the 
preparation  of  the  Immedial  colors.  Immedial  black  produces  a  fast 
black  upon  cotton  which  can  be  oxidized  on  the  fibre  to  Immedial  blue. 

IV.  Analytical  Tests  and  Methods. 

In  this  section  it  is  not  the  intention  to  exhaust  the  subject  of  the 
chemical  examination  of  coal-tar  colors,  but  to  briefly  indicate  the  more 
important  and  characteristic  tests.  The  complete  chemical  analysis  of 
the  artificial  organic  dyes  is  very  seldom  resorted  to,  the  analyst  usually 
determining  the  identity  of  the  coloring  matter  by  means  of  the  tabular 


ANALYTICAL  TESTS  AND  METHODS.  469 

schemes  which  have  been  published  from  time  to  time  as  new  products 
have  appeared  on  the  market,  and  estimating  the  moisture  of  the  sample 
and  such  foreign  substances  as  the  sulphates  of  soda,  and  of  magnesia, 
salt,  sugar,  starch,  and  dextrine,  sand,  etc.  Of  considerable  value  in 
connection  with  the  above  is  a  dyed  sample  of  cloth  or  yarn,  which, 
although  not  strictly  a  chemical  test,  is  one  of  equal  importance,  espe- 
cially for  the  information  of  the  immediate  user  of  the  dye.  The  recog- 
nition of  dyes,  either  by  themselves  or  on  the  fibre,  is  often  desirable, 
but  this  requires  considerable  care  and  judgment,  from  the  fact  that  a 
very  large  number  are  simply  mixtures,  some  with  as  many  as  five 
separate  dyes ;  in  such  cases  the  task  is  almost  hopeless.  These  mixtures 
are  sometimes  made  at  the  color  manufactory,  and  again  by  the  local 
agent ;  in  the  latter  case,  usually  to  supply  some  particular  shade  called 
for,  and  generally  without  any  regard  to  the  chemical  nature  of  the  con- 
stituents; this  indiscriminate  mixing  accounts  in  a  measure  for  the 
streakiness  and  uneven  effects  noticed  in  dyeing  piece  goods  and  yarn 
with  such  colors,  which  cannot  always  be  detected  by  dyeing  the  small 
test  samples  in  the  laboratory. 

Fastness  to  Light  is  determined  by  exposing  one-half  of  a  dyed 
skein  or  piece  of  dyed  cloth  to  the  action  of  direct  sunlight  for  a  definite 
time,  say  thirty  days  or  longer. 

Fastness  to  Soap. — A  piece  of  dyed  cloth  or  yarn  is  worked  in  a  neu- 
tral soap  lather,  washed,  dried,  and  compared  with  the  original. 

Comparative  Dye-trials. — For  this  purpose  vessels  of  glass,  porce- 
lain, or  tinned  copper  are  most  convenient, — the  latter  is  the  best  suited, 
— and  if  means  can  be  had  to  provide  heating  by  steam,  it  leaves  nothing 
to  be  desired.  When  several  comparative  dyeings  are  to  be  made  at  one 
time  of  the  same  class  of  samples,  one  equal  temperature  is  necessary. 

For  Wool  and  Silk. — In  either  case  it  is  best  to  use  a  vessel  contain- 
ing about  one  litre.  From  twenty  to  twenty-five  grammes  of  wool  (yarn 
or  fabric)  and  about  five  to  ten  grammes  of  silk  answer  well  for  the 
tests.  The  quantity  of  dye  used  varies,  although  two  standards,  repre- 
senting one  per  cent,  and  five  per  cent,  of  the  weight  of  the  wool  or  silk, 
answer,  as  they  give  two  shades  which  are  convenient  for  estimating  the 
dyeing  value  of  the  sample.  To  make  the  test,  the  color  is  weighed  out 
carefully,  washed  into  the  dye-bath  containing  water,  and  brought  to 
the  boil,  into  which  the  material,  previously  wetted  out,  is  immersed  and 
kept  moving  about  for  a  definite  time,  say  twenty  to  thirty  minutes,  or 
until  the  bath  is  exhausted  of  color,  when  it  is  withdrawn,  washed,  dried, 
and  the  shade  compared  with  a  swatch  of  the  same  weight,  treated 
under  exactly  the  same  conditions  as  to  temperature,  time,  etc. 

To  determine  the  relative  dyeing  values  of  color  samples,  two  solu- 
tions of  equal  value  are  made  of  equal  (known)  weights  of  the  dyes, 
and  two  dyeings  are  made  as  above,  only  adding  the  dye  solution  to  the 
bath  as  fast  as  it  is  taken  up  by  the  fabric ;  a  point  will  be  reached  when 
no  more  color  will  be  taken  up,  when  the  addition  must  stop,  the  differ- 
ence in  the  volume  of  the  solution  remaining,  from  their  original  vol- 
ume, gives  the  amount  used  in  each  test ;  and  as  the  strength  was  known, 


470  THE  ARTIFICIAL  COLORING  MATTERS. 

the  relative  amounts  absorbed  by  the  fabric  can  be  calculated.  The 
above  applies  equally  to  silk.  No  general  rule  can  be  given  which  will 
embrace  the  application  of  the  colors  to  fibres  in  testing,  reference  must 
be  had  to  the  various  classes  of  dyes  and  methods  in  Chapter  XIV. 

For  Cotton. — Few  colors  are  directly  applicable  to  this  fibre  without 
previously  mordanting  it  with  suitable  substances  which  will  cause  the 
color  to  remain.  In  the  laboratory,  a  quantity  of  cotton  is  taken  (yarn 
or  piece) ,  boiled  well  in  water  and  immersed  in  a  five  per  cent,  solution 
of  tannin  for  about  twelve  hours,  when  it  is  removed  and  boiled  in  a 
bath  containing  two  and  a  half  per  cent,  of  tartar  emetic  for  thirty  to 
forty-five  minutes,  washed,  dried,  and  kept  for  use.  (Other  mordants — 
e.g.,  tin,  iron,  alumina,  etc. — are  used  according  to  the  kind  of  work 
done  in  the  establishment.)  In  the  matter  of  printed  goods,  swatches 
of  cotton  cloth,  mordanted  on  one  piece  with  several  bases,  are  made  by 
the  printer,  and  these  are  then  passed  through  one  solution  of  color,  and 
the  effect  can  be  conveniently  noticed. 

For  Woollen  Yarn  Printing. — Pastes  are  made  up  of  the  color  in 
varying  strengths  with  starch  or  flour,  and  with  such  assistants  as  may 
be  required,  such  as  oxalic  or  tartar ic  acids,  stannous  chloride,  etc.,  in 
the  following  manner:  Five  grammes  of  color  are  taken  and  mixed  with 
a  little  water  containing  dextrine  or  glycerine,  and  this  is  made  up  to 
five  hundred  cubic  centimetres  with  a  paste  of  flour  (one  pound  per 
gallon).  Twenty  or  thirty  strands  of  yarn  about  a  metre  long  are 
taken,  held  at  one  end,  and  the  color-paste  rubbed  well  in  for  a  space 
of  about  six  inches  with  a  glass  rod  or  spatula;  one-tenth  of  the  color- 
paste  is  emptied  out,  and  the  remaining  is  diluted  again  to  five  hundred 
cubic  centimetres,  and  this  is  then  applied  to  the  yarn,  leaving  a  space 
of  an  inch  or  so  from  the  first.  The  diluting  operation  is  continued  so 
that  the  printings  on  the  yarn  will  represent  color  in  the  proportion  of 
1,  .9,  .8,  .7,  etc.,  giving  a  range  of  shades  of  one  color.  The  yarn  so 
printed  is  then  steamed  for  about  twenty  to  thirty  minutes  under 
pressure,  or  longer  without  pressure,  washed,  and  dried.  This  method 
is  of  much  value  in  matching  and  valuing  shades  in  tapestry  carpets. 

By  Colorimetry. — This  method  involves  the  use  of  two  graduated 
glass  tubes,  closed  at  one  end,  each  of  the  same  diameter,  thickness,  and 
length.  The  standard  sample  of  dye  being  weighed  and  dissolved  in 
water,  is  poured  into  one  tube,  while  an  equal  weight  of  the  sample  to 
be  tested  is  poured  into  the  other,  and  by  holding  the  tubes  to  the  light 
the  depth  of  color  is  seen.  If  one  is  darker  in  shade  than  the  other,  it 
is  diluted  until  the  shades  are  equal,  when,  by  knowing  the  number  of 
cubic  centimetres  of  water  added  to  equalize  the  tint,  the  relative 
strength  of  the  dyes  can  be  ascertained. 

Mixtures  of  Dyes  can  be  detected  by  sprinkling  some  of  the  powder 
on  the  surface  of  distilled  water,  and  noticing  the  color  of  the  streaks 
formed  as  the  particles  subside,  or  by  dissolving  the  dye  in  a  little 
alcohol  and  water  contained  in  a  small  exaporating  dish  or  beaker,  and 
immersing  therein  the  end  of  a  strip  of  white  blotting-paper,  when,  in 
the  case  of  mixtures,  several  differently-colored  bands  are  seen  on  the 


ANALYTICAL  TESTS  AND  METHODS. 


471 


paper,  owing  to  the  fact  that  the  constituents  of  the  mixture  do  not 
always  possess  the  same  degree  of  capillarity.  These  bands  can  be  cut 
off  and  separately  tested  by  proper  reagents  according  to  the  scheme  for 
identification  of  dyes  following.  Fractional  dyeing  has  also  furnished 
information  of  value ;  usually  wool  or  silk  being  employed. 

Identification  of  Coal-tar  Ztyes.— Weingartner's  comprehensive  tables, 
which  follow,  afford  means  of  determining  the  group  to  which  a  sample 
of  dye  under  examination  belongs.  The  dyes  are  divided  conveniently 
into  two  divisions,  basic  and  acid  coloring  matters,  and  the  latter  into 
soluble  and  insoluble  in  water. 

I.  The  Dye  is  Soluble  in  Water. — Add  a  few  drops  of  a  solution  of 
tannin  *  to  a  solution  of  the  dye,  and  note  the  formation  of  a  precipi- 
tate, after  heating. 

A.  Precipitation  takes  Place. — The  color  is  basic. — A  small  quantity 
of  the  original  color  is  dissolved  in  water,  and  reduced  with  hydro- 
chloric acid  and  zinc-dust,  rapidly  filtered,  and  neutralized  with  sodium 
acetate;  small  strips  of  filter-paper  are  immersed  in  the  solution,  and 
exposed  to  oxidize. 


THE  ORIGINAL  COLOR  REAPPEARS  ON  THE  PAPER. 

The  original 
color  does  not 
reappear. 

Reds. 

Oranges  and 
yellows. 

Greens. 

Blues. 

Violets. 

FUCHSINE, 

PHOSPHINE, 

MALACHITE 

METHYLENE 

METHYL  VIOLET. 

CHRYSOIDINE. 

MAGENTA, 

CHRYSANI- 

GREEN,    VIC- 

BLUE. With 

Sulphuric  acid 

Color,  orange. 

BOSOM  K, 

LINE.    With 

TORIA  GREEN. 

sulphuric 

causes  a  yel- 

In sulphuric 

With  sul- 

sulphuric acid, 

With  sulphuric 

acid,  green. 

lowish-brown 

acid,  dis- 

phuric acid, 

reddish-yel- 

acid, yellow, 

Caustic  soda 

coloration  ;  on 

solves  to  a 

Drown. 

low  precipi- 

on diluting 

causes  vio- 

dilution 

brownish- 

NEUTKALRED. 

tate.    Green 

with  water, 

let-black" 

changes  to 

yellow  solu- 

With sul- 

fluorescence. 

green.  Ammo- 

precipitate. 

green  and  vio- 

tion. 

phuric  acid, 

Caustic  soda, 

nia  causes 

NEW  BLUE. 

let-blue. 

VESUVINE. 

green.   With 

light-yellow 

gray  or  red 

With  caustic 

NEUTRAL  VIO- 

Color, brown, 

caustic  soda 

Erecipitate. 

precipitate. 

soda,  blue- 

LET.  Sulphuric 

upon  silk, 

solution,  yel- 

oluble in 

BRILLIANT 

black  pre- 

acid causes 

orange.    In 

low-brown 

ether  with 

GREEN.    With 

cipitate. 

bright  violet 

sulphuric 

precipitate. 

green  fluores- 

sulphuric acid, 

MUSCARINE. 

color  ;  on  dilu- 

acid, soluble 

SAFRANINE. 

cence. 

same  as  above, 

Caustic  soda 

tion  changes 

to  a  pale 

With  sul- 

FLAVANILINE. 

color  reap- 

causes 

to  blue. 

liquid. 

phuric  acid, 

With  sulphuric 

pears  slowly. 

brownish- 

MAUVEINE. 

AURAMINE. 

green.  Caus- 
tic soda, 

acid,  dirty  yel- 
low precipi- 

Ammonia, lit- 
tle or  no  pre- 

red precipi- 
tate.   With 

Sulphuric  acid 
causes  gray 

Color,  yellow. 
With  alkalies, 

brownish- 

tate.   Soluble 

cipitate. 

tannin. 

color;  on  dilu- 

white pre- 

red precipi- 

in ether  with 

METHYL  GREEN, 

indigo-blue 

tion  changes 

cipitate. 

tate. 

blue  fluores- 

PARIS GREEN. 

precipitate. 

to  light  blue 

On  warming 

PYRONINE. 

cence. 

With  sulphuric 

CAPRI  BLUE. 

and  violet-red. 

with  sul- 

ACRIDINE 

ACRIDINE  YEL- 

acid, same  as 

MELDOLA'S 

AMETHYST. 

phuric  acid, 

RED. 

LOW. 

above,  color 

BLUE. 

Sulphuric  acid 

solution  de- 

TOLUYLENE 

ACRIDINE 

not  reappear- 

METAPHENYL- 

gives  green 

colorized 

RED, 

ORANGE. 

ing  on  dilu- 

ENE BLUE. 

color;  blue  on 

VICTORIA 

tion.  Ammonia, 

INDAMINES. 

dilution. 

BLUE.  Color, 

solution  de- 

PRUNE. 

blue.     In  sul- 

composed, no 

PARAPHENYL- 

phuric  acid, 

precipitate. 

ENE  VIOLET. 

brownish- 

AZINE  GREEN. 

red,  changes 

to  bluish- 

green. 

*  Twenty-five   parts   of  tannin,   twenty-five   parts  of   acetate  ot   soda,  and  two 
hundred  and  fifty  parts  of  water. 


472 


THE  ARTIFICIAL  COLORING  MATTERS. 


B.  No  Precipitation  takes  Place. — The  color  is  acid. 


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ANALYTICAL  TESTS  AND  METHODS. 


473 


II.   The  Dye  is  Insoluble  in  Water. — Treat  with  a  five  per  cent,  solution 
of  caustic  soda. 


•  »B 

C  g  g 


pC  **  3 


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olution 
inc-dus 
the  sol 


ry,  t 
char 
e  im 


ginal  colo 
reappear. 


o  ft 

>H    g 

o  ii 


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colo 
pape 
the  a 


nec 
olo 
a 


he  original  c 
the  solution 
pears. 


ll 


ill! 


474  THE  ARTIFICIAL  COLORING  MATTERS. 

Dextrine. — This  substance  is  estimated  by  weighing  one  or  two 
grammes  of  the  dye  in  a  small  tared  beaker,  provided  with  a  glass  rod. 
The  dye  is  dissolved  in  a  little  water,  and  absolute  alcohol  added,  when 
the  dextrine  will  be  thrown  down,  and  adheres  closely  to  the  glass.  The 
contents  are  emptied,  and  the  glass  rinsed  two  or  three  times  with  alco- 
hol, dried,  and  weighed. 

Starch. — The  presence  of  this  substance  must  not  be  taken  as  an 
adulterant  in  every  case  it  is  found;  owing  to  its  peculiar  properties  it 
acts  as  a  drier  or  absorber  of  moistness,  and  hence  prevents  the  caking 
of  the  dye.  By  dissolving  a  quantity  of  the  dye  in  water,  and  allowing 
the  solution  to  stand  in  a  conical  glass  for  a  while,  any  starch  present 
will  subside,  the  clear  liquid  is  poured  off,  and  the  residue  repeatedly 
washed  with  distilled  water  and  alcohol  until  no  color  remains,  it  can 
then  be  examined  with  the  microscope ;  a  drop  is  placed  on  a  slide  with 
a  drop  of  water,  the  cover-glass  put  on,  and  a  drop  or  two  of  iodine 
solution  placed  on  the  edge,  and  allowed  to  displace  the  water  by  the 
aid  of  a  piece  of  filter-paper  opposite  the  iodine,  will,  if  starch  is  present, 
develop  the  characteristic  reaction, — blue. 

/S^ar.— Estimated  as  for  dextrine;  the  alcohol  used  should  be  satu- 
rated with  sugar.  Sugar  can  be  estimated  in  dyes  by  precipitating  the 
coloring  matter  with  basic  acetate  of  lead,  and  proceeding  as  for  raw 
sugar  with  the  polariscope  (see  page  173),  or  by  inverting  and  estimat- 
ing with  Fehling's  solution  (page  175). 

Sand  and  Iron  Filings  are  gross  adulterations  occasionally  met  with 
in  dyes  from  unprincipled  dealers.  Their  presence  would  have  been 
noticed  under  the  insoluble  matter  determination.  Iron  filings  can  be 
easily  determined  with  a  magnet. 

A  careful  microscopic  examination  of  ground  and  crystallized  dyes 
will  throw  much  light  on  their  preparation;  bronze-powder  and  sugar 
crystals  have  been  thus  found. 

Paste-dyes,  etc.,  are  best  estimated  by  evaporating  a  weighed  quan- 
tity to  absolute  dryness  in  a  small  glass  mortar,  grind  thoroughly,  add 
water,  and  filter  through  a  tared  filter,  wash  with  water,  dry,  and  weigh. 
If  this  is  not  done,  trouble  will  be  met;  paste-dyes  not  filtering  well  if 
simply  diluted  with  water. 

The  Examination  of  Dyed  Fibres  can  well  be  accomplished  by  the 
aid  of  the  following  table,  which  is  adapted  from  those  of  Hummell,* 
of  R.  Lepetit,f  and  of  Lehne  and  Rusterholz,J  and  embraces  a  majority 
of  the  more  important  coloring  matters  which  have  found  application. 
The  reagents  employed  are  Hydrochloric  acid  (HC1),  concentrated,  21° 
Beaume,  and  dilute,  one  part  of  acid  21°  B.  and  three  parts  water;  sul- 
phuric acid  (H2S04),  concentrated,  66°  B.,  and  dilute,  one  part  of  acid 
66°  B.  and  five  parts  of  water;  nitric  acid  (HNCK,),  concentrated.,  specific 
gravity  1.40,  dilute  one  part  of  the  strong  acid  and  two  parts  of  water; 
caustic  soda  solution  (NaOH),  concentrated,  38°  B.,  and  dilute,  one 

*  Hummell,  The  Dyeing  of  Textile  Fabrics,  London,  1885. 

fR.  Lepetit,  Journ.  Soc.  Chem.  Ind.,  vol.  viii,  p.  773  (from  Zeits.  f.  angew. 
Chem.,  1888,  535).  $  Farber-zeitung,  1891,  Hefte  11,  13,  etc. 


ANALYTICAL  TESTS  AND  METHODS.  475 

part  of  the  strong  solution  and  ten  parts  of  water;  ammonia,  specific 
gravity  .960;  alcohol,  ninety-six  per  cent.;  stannous  chloride,  tin  salt 
(SnCl2  +  2H2O),  and  concentrated  hydrochloric  acid  equal  parts; 
acetate  of  ammonia  solution,  by  neutralizing  ammonia  with  pure  acetic 
acid  and  bringing  exactly  to  5°  B. 

The  initials  or  names  in  parentheses  following  the  names  of  the  dye- 
colors  are  those  of  the  manufacturers  who  furnish  the  particular  dye- 
stuff,  and  will  be  readily  understood  by  those  accustomed  to  handle  these 
wares. 

A  separate  column  has  not  been  made  for  nitric  acid,  but  where  its 
action  is  distinctive  it  is  noted  under  the  head  of  remarks. 

Method  of  Procedure. — For  the  testing  with  concentrated  acids  and 
caustic  alkalies  small  watch-crystals  are  most  advantageously  used. 
These  are  then  placed  upon  white  paper  in  order  to  be  able  to  observe 
carefully  the  changes  of  color.  The  concentrated  acids  are  most  con- 
veniently dropped  from  small  dropping  tubes  or  pipettes,  so  that  they 
can  be  added  drop  by  drop  until  the  fibre  is  completely  covered.  After 
addition  of  the  acids  four  to  five  minutes  are  allowed,  and  the  action  is 
then  noted.  The  watch-crystals  are  then  heated  carefully  by  using  a 
very  small  flame  or  placing  them  upon  a  steam-coil,  but  the  liquids  upon 
the  watch-crystals  should  not  be  allowed  to  boil.  After  waiting  a  few 
minutes  and  allowing  them  to  cool,  water  is  added  to  the  contents  of 
the  watch-crystals. 

All  the  other  reactions  of  the  tables  are  carried  out  in  test-tubes. 
The  fibre  is  placed  in  the  test-tube,  covered  with  the  reagent,  and  al- 
lowed to  stand  for  several  minutes,  then  heated  without  quite  bringing 
the  liquids  to  the  boiling-point,  when  the  action  is  carefully  noted. 
Finally  the  liquids  are  boiled  for  a  short  time.  The  solution  is  then 
poured  off  and  caustic  alkali  or  acid,  as  the  case  may  be,  is  added,  and 
any  change  carefully  noted.  After  the  tests  with  concentrated  hydro- 
chloric or  sulphuric  acids  the  fibres  are  well  washed  with  water  in  order 
to  observe  whether  the  original  color  is  thereby  restored. 


476 


THE  ARTIFICIAL  COLORING  MATTERS. 


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BIBLIOGRAPHY  AND  STATISTICS.  485 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

1879. — History  of  Aniline  and  Allied  Coloring  Matters,  W.  H.  Perkin,  London. 

Les  Matieres  colorantes  artificielles,  A.  Wurtz,  Paris. 
1880. — Das  Anthracene  und  seine  Derivate,  G.  Auerbach,  2te  Auf.,  Braunschweig. 

Die  neuere  Entwickelung  der  Theerfarben-Industrie,  Dr.  R.  Meyer,  Braunsch- 
weig. 

Lehrbuch  der  Farbenfabrikation,  J.  G.  Gentele,  2te  Auf.,  Braunschweig. 
1881. — Die  Industrie  der  Theerfarbstoffe,  C.   Haussermann,  Stuttgart. 
1882. — Manual  of  Colors  and  Dye-wares,  J.  W.  Slater,  London.      ' 
1883. — Matieres  colorantes  et  les  Applications,  Girard  et  Pabst,  Paris. 
1887. — Die  kiinstlichen   organischen   Farbstoffe,   P.   Julius,   Berlin. 

Fortschritte   der  Theerfarbenfabrikation,   P.   Friedlander,   Berlin. 
Die  Anilin-Farbstoffe,  A.  Kertesz,  Braunschweig. 

1889. — Sur  la  Constitution  de  la  Naphthaline  et  de  ses  Derives,  Reverdin  et  Noelt- 
ing, Mul  house. 
Die  Fabrikation  der  Theerfarbstoffe  und  ihre  Rohmaterialen,  W.  Harmsen, 

Berlin. 

Die  Technik  der  Rosanilinfarbstoffe,  O.  Miihlhauser,  Stuttgart. 
Histoire  scientifique  et  industrielle  du  Noir  d'Aniline,  Noelting,  Mulhouse. 
1890. — Die  organische  Farbstoffe,  R.  Mohlau,  Dresden. 

Les  Matieres  colorantes,  etc.,  C.  L.  Tassart,  Paris. 

Traite  pratique  des  Matieres  colorantes  artificielles,  A.  M.  Villon,  Paris. 
1891. — Tabellarische  Uebersicht  der  kiinstlichen  organischen  Farbstoffe,  Schultz  und 

Julius,  2te  Auf.,  Berlin. 
Fortschritte   der   Theerfarbenfabrikation,   etc.,   2te   Abtheilung,   Friedlander, 

Berlin. 
Carbolsaure  und  Carbolsiiure  praeparate,  H.  Kohler,  Berlin. 

1892 Anilinschwarz  und  seine  Anwendung,  Noelting  und  Lehne,   Berlin. 

Chemistry  of  the  Organic  Dye-stuffs,  R.  Nietzki,  translated  by  Collin  and 

Richardson,  London. 

The  Coal-Tar  Colors  with  Reference  to  Injurious  Qualities,  Th.  Weyl,  trans- 
lated by  Henry  Leffman,  Philadelphia. 

1893. — Ueber  die  Entwickelung  der  Theerfarben-Industrie,  H.  Caro,  Berlin. 
1894. — Tabellarische  Uebersicht  der  kiinstlichen  organischen  Farbstoffe,  A.  Lehne, 

Berlin. 

Tabellarische  Uebersicht  der  Naphthalin  Derivate,  Reverdin  und  Fulda,  Basel. 
1895. — Lehrbuch  der  Farbenchemie,  J.  G.  Georgievics,  Wien. 
1896. — Dictionary  of  the  Coal-Tar  Colors,  2d  ed.,  Hurst,  London. 

Fortsehritte   der   Theerfarbenfabrikation,   P.   Friedlander,   3te   Theil,   Berlin. 
Trait6    des    Matieres    colorantes    organiques    artificielles,    Leon    Lefevre,    2 

tomes,  Paris. 
Bolley's  Handbuch  der  Chem.  Technologie,  Band  v. ;  Die  Theerfarbstoffe,  bei 

Kopp,  R.Meyer,  und  R.  Gnehm,  Braunschweig. 
1898. — Tabellarische  Uebersicht  der  kiinstlichen  organischen  Farbstoffe,  A.  Lehne, 

Erganzungs-band,  Berlin. 

Farbereichemische  Untersuchungen,  Paul  Heermann,  Berlin. 
Chemische  Technologie  der  Azofarbstoffe,  C.  Billow,  2  Bde.,  Leipzig. 
Geschichte  und  Systematik  der  Indigo-Synthesen,  A.  Reissert,  Berlin. 
1899. — Les  Matieres  colorantes  azoiques,  G.  F.  Jaubert,  Paris. 

Fortschritte   der   Theerfarbenfabrikation,   P.   Friedlander,   4te   Theil,   Berlin. 


486  THE  ARTIFICIAL  COLORING  MATTERS. 

1900. — Chemistry  of  the  Coal-Tar  Colors,  R.  Benedikt,  translated  by  Knecht,  3d  ed., 

London. 

The  Manufacture  of  Lake  Pigments  from  Artificial  Colors,  Francis  H.  Jen- 
nison,  London. 

1901 Die  Chemie  des  Steinkohlenteers,  G.  Schultz,  3d  Auf.,  2  Bd,  Braunschweig. 

1903. — The  Chemistry  of  Dyestuffs,   G.   von   Georgievics,   translated  by  C.    Salter, 

London. 
1904. — Systematic  Survey  of  Organic  Coloring  Matters,  founded  on  the  German  of 

Schultz  and  Julius,  by  Arthur  J.  Green,  2d  edition. 

Anilin-schwarz  und  seine  Anwendung,  Noelting  und  Lehne-Springer,  Berlin. 
1905. — The   Synthetic  Dyestuffs   and  Intermediate   Products,  J.   C.   Cain  and  J.   F. 

Thorpe,  London  and  Philadelphia. 
1906. — Die  Chemie  der  Organischen  Farbstoffe,  R.  Nietzki,  5th  Auf.,  J.  Springer, 

Berlin. 
Die   Anilinfarben   und    ihre   Fabrikation,   K.   Heumann,   Herausgegeben  von 

Gustav  Schultz,  in  4  Theilen,  1888-1906,  Braunschweig. 
1907. — Handbuch   der   Farben-fabrikation,   Untersuchung,   etc.,   Georg  Zerr  und  R. 

Rubenkamp. 

Bestimmung  von  Teerfarbstoffen  in  Farblacken,  Georg.  Zerr,  Dresden. 
1909. — Organische  Farbstoffe,  Dr.  H.  Wichelhaus,  Theo.  Steinkopf,  Dresden. 
1910. — Identification  of  the  Commercial  Dyestuffs,  S.  P.  Mulliken,  J.  Wiley  &  Son, 

New  York. 
1911. — The  Coal-Tar  Colors;    their  Origin  and  Chemistry,  J.  W.  Fay,  D.  Van  Nos- 

trand,  New  York. 
The  Chemistry  of  the  Diazo  Compounds,  John  C.  Cain,  Longmans,  Green  & 

Co.,  New  York. 

Coal-Tar  Colors  in  Aniline  Lakes,  G.  Zerr,  translated  by  Mayer,  London  and 
Philadelphia. 

STATISTICS. 

1.  CRUDE  MATERIALS  OF  THE  COLOR  INDUSTRY. — Schultz  (Chemie  des 
Steinkohlentheers,  1900,  3d  ed.,  p.  9)  states  that  the  present  production 
of  coal-tar  throughout  the  world  is  as  follows:  England,  660,000  tons; 
Germany,   160,000  tons;   France,   80,000  tons;   Belgium,   50,000  tons; 
Holland,  30,000  tons;  America,  120,000  tons;  total,  1,100,000  tons. 

The  yearly  production  of  benzol  and  toluol  from  coal-tar  and  coke- 
oven  gases  was  estimated  by  Dr.  H.  Brunck  in  1901  to  be  from  25,000 
to  30,000  tons,  of  which  benzol  made  up  four-fifths.  Of  this  production 
Germany  furnished  at  that  time  one-third,  but  the  proportion  has  prob- 
ably increased  since. 

The  same  authority  estimated  the  yearly  production  of  naphthalene 
to  be  from  40,000  to  50,000  tons. 

The  German  production  of  phenol  and  cresol  in  1902  was  estimated 
by  Witt  (Die  Chem.  Industrie  des  Deutschen  Reiches,  1902,  p.  199) 
to  be  from  4400  to  4800  tons  per  annum,  of  naphthalene  to  be  about 
17,000  tons,  and  of  anthracene  to  be  from  4400  to  4800  tons. 

2.  GERMAN    COAL-TAR   COLOR    STATISTICS. — The     German    trade   in 
aniline  oil,  aniline  salts  and  other  crude  coal-tar  products  was : 

1900.         1902.          1904.        1905.        1907. 

Imports   in   tons    1,241  1,233  2,099  1,624  137 

Value   in   marks    ....   1,120,000         1,130,000         1,890,000         1,460,000          130,000 

Exports   in   tons    12,613  15,969  16,756  19,421  8,704 

Value   in   marks    11,350,000       14,690,000       20,110,000       23,890,000       8,050,000 

(Gustav  Miiller,  Die  Chemische  Industrie,  Berlin,  1909,  p.  378.) 


BIBLIOGRAPHY  AND  STATISTICS.  487 

The  German  trade  for  the  same  years  in  aniline  and  other  unspecified 
coal-tar  colors  was: 

1900.         1902.         1904.         1905.        1907. 

Imports   in   tons    1,174  1,179  1,461  1,743  2,054 

Value   in   marks    3,820,000        3,650,000        4,240,000        4,790,000       5,240,000 

Exports   in   tons    23,781  28,805  30,831  36,570  43,716 

Value   in   marks    77,290,000       89,300,000       88,590,000     100,650,000  112,500,000 

(Ibid.,  p.  379.) 

The  German  trade  in  alizarin  and  alizarin  colors  in  recent  years  has 
been: 

1900.  1905.  1907. 

Imports   in   tons    39  79  53 

Value   in   marks    40,000  110,000  100,000 

Exports    in  tons    8,591  9,339  10,442 

Value   in   marks    11,170,000  15,530,000  23,430,000 

(Ibid.,  p.  377.) 

The  German  trade  in  indigo  was  as  follows: 


1902. 

1903. 

1904. 

1905. 

1907. 

Imports   in   tons    .  . 

527 

291 

260 

197 

127 

Value   in   marks    .  . 

.  .   3,690,000 

1,790,000 

1,350,000 

1,200,000 

1,080,000 

Exports   in   tons    .  . 

5,284 

7,233 

8,730 

11,165 

16,350 

Value   in   marks    .  . 

.  .  18,460,000 

20,690,000 

21,660,000 

25,720,000 

42,580,000 

(Ibid.,  p.  375.) 

The  value  in  marks  of  the  coal-tar  colors  exported  by  Germany  in 
recent  years  as  summarized  is  as  follows : 

1900.                       1905.  1907. 

Alizarin  .                . .  -,  9,630,000 

Alizarin  dye  colors .  } 11,170,000         15,500,000  13;80o;ooo 

Indigo      9,360,000         25,700,000  42,580,000 

Aniline     and     unspecified     coal- 
tar   colors    77,290,000       100,700,000  112,480,000 


97,820,000       141,900,000       178,490,000 
(Ibid.,  p.  380.) 

To  these  may  be  added  the  totals  for  the  two  following  years,  viz.: 

For  1908,  208,654,000  marks,  and  for  1909,  235,354,000  marks. 

(Fischer's  Jahresbericht  der  chem.  Tech.,  1910,  p.  583.) 

3.  UNITED  STATES  IMPORTATIONS  OF  DYE-COLORS. 

1908.                          1909.  1910. 

Alizarin  and  alizarin  dyes  in  pounds 3,964,126  3,749,869  3,023,348 

Value    $753,371  $1,215,700  $647,944 

Aniline    salts     (pounds) 5,407,790  6,132,517  5,866,982 

Value    $462,332              $543,538  $515,623 

Coal-tar  colors  and  dyes  valued  at $4,883,675  $5,901,842  $6,011,054 

Indigo    (pounds)    6,078,073  8,249,972  7,538,689 

Value    $1,058,354  $1,400,286  $1,195,942 

(Commerce  and  Navigation  U.  S.,  1910.) 


488  NATURAL  DYE-COLORS. 


CHAPTER  XIII. 

NATURAL    DYE-COLORS. 

I.  Raw  Materials. 

THE  raw  materials  to  be  described  here  are  a  series  of  vegetable  dyes 
coming  into  commerce  partly  as  compact  heart  woods  and  roots  and 
partly  as  masses  of  separated  coloring  matters,  together  with  a  few  dried 
animal  remains  yielding  coloring  matters.  We  shall  take  them  up  most 
conventiently  in  groups  according  to  the  colors  yielded. 

A.  RED  DYES. 

1.  Brazil-wood  and  Allied  Woods  (syn.  Rothholz,  Bois  de  Bresil). — 
The  various  species  of  Ccvsalpinia  yield  woods  which  appear  to  contain 
a  common  chromogen,  brasilin,  C16H14O5.     This  seems  already  in  the 
wood  to  be  changed  in  part  into  the  corresponding  coloring  matter. 
brasilein,  C16H1205.     And  the  change  may  be  made  complete  by  oxidiz- 
ing the  alkaline  brasilin  solution  in  the  air  by  acting  upon  a  hot  solution 
of  brasilin  with  an  alcoholic  iodine  solution.     Liebermann  and  Burg 
ascribe  to  the  crystals  of  brasilin  the  formula  C16H1405  -J-  H20,  and  call 
attention  to  the  fact  that  it  bears  the  same  relation  to  hasmatoxylin, 
C16H14O6    (see   p.   496),   that   alizarin   bears   to   purpurin.      The   best- 
known  varieties  of  the  wood  are  known  by  the  following  special  names : 
Pernambuco-wood,  from  Ccesalpinia  crista,  grown  in  Brazil  and  Jamaica, 
yellowish-red  in  the  interior,  becoming  red  and  reddish-brown  on  the 
surface.     Brazil-wood,  from  Ccesalpinia  Brasiliensis,  grown  in  Brazil, 
as  well  as  the  Antilles  and  Bahamas,  is  brick-red  in  the  interior,  becom- 
ing brown-red  on  the  surface.     It  is  inferior  in  coloring  power  to  Per- 
nambuco-wood.    Sapan-wood,  from  Ccesalpinia  sappan,  grown  in  Siam, 
China,  Japan,  Ceylon,  and  the  Indian  Archipelago,  is  somewhat  lighter 
in  color  than  the  other  varieties.     It  is  yellowish-red  in  the  interior 
and  bright  red  on  the  surface.     Lima-wood,  or  Nicaragua-wood,  from 
Ccesalpinia  bijuga,  is  grown  in  Central  America  and  the  north  coast  of 
South  America.     The   Santa-Martha-wood   of  Mexico  and  Peach-wood 
are  by  some  writers  considered  as  of  the  same  species  as  Nicaragua- 
wood,  and  by  others  are  derived  from  Ccesalpinia  eckinata.     They  have 
a  dirty-red  color  in  the  interior,  becoming  paler  on  the  surface.     Bahia- 
wood,   California-wood,    and   Terra-Firma-wood   are   other  less   known 
varieties  of  the  same  class. 

2.  Sandal-wood,    Caliatur-wood,    Bar-wood,   "£nd    Cam-wood     (syn. 
Santelholz,  Bois  de  Santal  rouge)  form  another  group  of  woods  which  are 
alike  in  many  particulars  and  contain  probably  the  same  coloring  mat- 
ter, santalin,  C15H14Or>.     They  differ  as  a  class  from  the  Brazil-woods  in 
their  more  resinous  characters,  and  are  often  known  as  "  close  woods  " 


RAW  MATERIALS. 


489 


in  contrast  to  the  others  as  "  open  woods."  The  Sandal-wood  (Red 
Sanders),  from  Pterocarpus  santalinus,  is  grown  in  the  East  Indies, 
Ceylon,  and  Madagascar,  and  is  a  very  hard  and  heavy  wood,  dark  brown 
on  the  surface  and  blood-red  in  the  interior.  Caliatur-wood  comes  also 
from  the  East  Indies,  and  though  used  as  a  substitute  for  the  sandal- 
wood  is  considered  as  a  distinct  variety.  Sandal-wood  is  said  to  contain 
some  sixteen  per  cent,  of  santalin.  Bar-wood,  from  Baphia  nitida, 
comes  from  Sierra  Leone,  Africa,,  and  is  a  dark-red  wood,  containing 


Fia.  112. 


twenty-three  per  cent,  of  santalin.  Cam-wood  (or  Gaban-wood)  is  sup- 
posed by  many  to  be  the  same  as  bar-wood,  but  by  others  is  ascribed  to 
species  of  Peterocarpus.  It  comes,  like  bar-wood,  from  the  west  coast 
of  Africa.  Madagascar-wood  is  a  minor  variety  resembling  Caliatur- 
wood. 

3.  Madder  (syn.  Krapp,  Racine  de  Garance)  is  the  dried  and  broken 
root  of  the  Rubia  tinctorium  and  allied  species.  It  grows  wild  in  Asia 
Minor,  Greece,  and  the  Caucasus,  and  has  been  cultivated  in  France, 
Alsace,  Silesia,  Hungary,  Holland,  etc.  The  appearance  of  the  plant 
may  be  seen  from  Fig.  112,  in  which  it  forms  the  right-hand  illustra- 
tion. 


490  NATURAL  DYE-COLORS. 

In  the  Levant,  the  five-  to  six-year-old  plants  are  plucked,  in  Europe, 
those  two  to  three  years  old.  While  the  Turkish  madder  (known  as 
Lizari  or  Alizari)  was  the  earliest  in  use,  the  French  variety  grown  in 
the  neighborhood  of  Avignon,  in  part  upon  marshy  soil  (palus)  and  in 
part  upon  soil  containing  lime  (rosee),  has  long  been  considered  the 
best.  Other  varieties  are  the  Dutch  or  Zealand  madder,  the  Alsatian, 
the  Silesian,  and  the  Russian  madder.  That  which  has  not  been  freed 
from  the  brown  outer  crust  before  grinding  is  inferior  to  that  which  has 
been  so  freed,  and  which  is  known  as  "  crop-madder,"  while  the  im- 
purest  variety,  obtained  by  grinding  the  rootlets,  crusts,  and  woody 
parts  of  the  roots,  is  called  "  mull-madder." 

From  the  madder-roots  are  also  -prepared  by  fermentation  and  filtra- 
tion of  the  separated  dye-colors  the  commercial  extracts  known  as 
"  madder  flowers  "  and  "  guarancine."  One  hundred  kilos,  of  madder 
will  yield  fifty-five  to  sixty  kilos,  of  madder  flowers. 

The  tinctorial  value  of  the  madder  depends  upon  the  existence  of  the 
two  coloring  matters,  alizarin,  C14H8O4,  and  purpurin,  C14H805,  both  of 
which  have  been  mentioned  under  the  artificial  dye-colors  derived  from 
anthracene.  (See  p.  466.)  These  are  not  found  free  in  the  growing 
plant,  but  combined  as  glucosides  and  other  compounds  easily  decom- 
posable by  fermentation.  As  a  nitrogenous  and  soluble  ferment 
erythrozym  is  present;  so  soon  as  the  solutions  of  madder  extract  are 
exposed  to  the  air  the  ruberythric  acid  (or  alizarin  glucoside)  is  decom- 
posed into  alizarin  and  dextrose  and  the  pseudo-purpurin  (or  naturally 
occurring  purpurin-carboxylic  acid)  is  decomposed  into  purpurin  and 
carbon  dioxide.  Two  other  anthracene  derivatives  also  occur  in  madder, 
both  probably  as  decomposition  products  of  pseudo-purpurin,  munjistin, 
C15H806,  and  xanthopurpurin,  C14H8O4  (the  latter  of  which  is  isomeric 
with  alizarin). 

The  importance  of  madder  and  madder  preparations  has  almost  en- 
tirely disappeared  with  the  development  of  the  artificial  alizarin  manu- 
facture. The  colors  obtainable  from  alizarin,  isopurpurin  or  anthra- 
purpurin,  and  flavopurpurin,  which  are  the  products  of  the  synthetical 
methods,  have  almost  entirely  replaced  those  formerly  obtained  from 
madder. 

4.  Safflower  (syn.  Safflor,  Fleurs  de  Carthame)  consists  of  the  dried 
flowers  of  the  Carthamus  tinctorius,  a  plant  first  grown  in  Egypt  and 
the  East  Indies,  but  now  grown  in  Asia  Minor,  Spain,  Alsace,  Austria, 
and  Central  Germany.  The  flowers  are  of  a  deep  reddish-orange  color, 
and  contain,  besides  a  yellow  coloring  matter  of  no  technical  value, 
carthamin,  or  carthamic  acid,  C14H1(i07,  a  red  dye  of  considerable  im- 
portance for  silk-  and  cotton-dyeing.  It  forms  from  .3  to  .6  per  cent, 
of  the  weight  of -the  flowers.  "  Safflower  carmine  "  is  a  solution  of  the 
carthamin  in  soda,  and  "  plate  carthamine  "  is  a  pure  preparation  of 
the  dye  which  has  been  dried  in  crusts  upon  glass  or  porcelain  plates. 
The  most  important  commercial  varieties  of  safflower  are  the  Egyptian, 
which  is  the  richest  in  dye-color,  the  East  Indian,  the  Spanish,  and  the 
German.  Safflower  comes  from  Spain  and  France,  the  production  hav- 


RAW  MATERIALS.  .  491 

ing  amounted  in  recent  years  to  400,000  pounds.     However,  it  is  now 
almost  entirely  displaced  from  use  as  a  dye  by  the  artificial  dyes. 

5.  Orseille,  or  Archil  (syn.  Orseille,  Persia,  Cudbear). — The  various 
species  of  lichens,   as  Rocella  tinctoria  and   Rocella  fuciformis   from 
Angola,  Zanzibar,  Ceylon,  and  Mozambique,  as  well  as  from  the  Azores 
and  South  American  coast,  contain  a  mixture  of  phenols,  phenol-ethers, 
and  phenol-acids,  such  as  orcin    (or  orcinol),  erythric,  orcellinic  and 
lecanoric  (or  diorcellinic)  acids.     These  by  the  action  of  air  and  am- 
monia yield  orcein,  contained  in  the  orseille  (archil)   extract  as  a  red 
dye,  and  on  drying  the  extract  the  cud-bear  or  persio  as  a  reddish-violet 
powder. 

Archil  extract  occurs  in  commerce  in  two  forms,  paste  and  liquor. 
The  solid  matter  consists  mainly  of  the  impure  orcein  in  combination 
with  ammonia.  Its  preparation  will  be  referred  to  later.  Cudbear  (or 
Persio)  differs  mainly  from  the  orseille  extract  in  being  free  from  all 
excess  of  ammonia  and  moisture  and  in  being  reduced  to  a  fine  powder. 
An  illustration  of  the  orseille-yielding  lichens  is  given  in  Fig.  112  (see 
page  489)  in  the  lower  left-hand  figure. 

6.  Cochineal    (syn.   Cochenille)    is  the   dried  female   insect   Coccus 
Cacti,  which  lives  and  grows  on  the  plants  of  the  Cactus  family,  espe- 
cially the  "  nopal,"  or  Cactus  opuntia.     The  nopal-plant  is  indigenous 
to  Mexico,  but  is  also  cultivated  largely  in  Central  America,  the  Canary 
Islands,  the  Island  of  Teneriffe,  Algeria,  and  the  East  Indies. 

The  commercial  varieties  of  cochineal  are  known  as  the  silvery-gray 
and  the  black  cochineal.  These  varieties  are  apparently  produced  ac- 
cording to  the  method  adopted  for  killing  the  insects  when  they  are 
swept  off  the  leaves  of  the  nopal-plant.  If  killed  by  immersion  in  hot 
water  or  by  steam  they  lose  the  whitish  dust  with  which  they  are  covered 
and  constitute  the  black  variety  (zaccatila) ;  if  killed  by  dry  heat  in 
ovens  this  dust  remains  and  they  yield  the  silvery-gray  variety  (bianco}. 
This  latter  is  considered  the  better,  and  is  sometimes  simulated  by  dust- 
ing the  black  variety  with  powdered  talc,  gypsum,  barytes,  or  stearic 
acid.  The  natural  gray  powder  is  a  variety  of  wax  known  as  coccerin. 

The  coloring  matter  of  the  cochineal  is  carminic  acid,  C17H18010,  and 
may  amount  to  fifteen  per  cent,  of  the  weight  of  the  dried  cochineal, 
although  Liebermann  states  that  the  average  is  from  nine  to  ten  per 
cent.  Carminic  acid  is  a  purple  substance  soluble  in  water  and  alcohol, 
but  only  slightly  so  in  ether.  Chlorine  readily  destroys  the  carminic 
acid  and  nascent  hydrogen  reduces  it  to  a  leuco  body,  which  again  be- 
comes red  on  exposure  to  the  air.  Chemically  it  is  a  glucoside,  being 
capable  of  decomposition  into  carmine-red,  CUH12O7,  and  a  sugar, 
C6H10O5. 

Carminic  acid  dissolves  in  caustic  alkalies  with  a  beautiful  red  color, 
forms  purple  precipitates  with  barium,  lime,  lead,  and  copper,  and  a 
fine  red  lake  with  alumina.  A  decoction  of  cochineal  behaves  with  re- 
agents somewhat  differently  from  a  solution  of  the  pure  carminic  acid 
owing  to  the  presence  of  phosphates,  tyrosine,  etc.  The  addition  of  alum 
or  stannic  chloride  to  it  yields  the  fine  red  pigment  known  as  ' '  cochineal 


492  NATURAL  DYE-COLORS. 

r 

carmine."     This  as  well  as  other  preparations  from  cochineal  will  be 
referred  to  again  under  products.     (See  p.  507.) 

7.  Kermes  (syn.  Kermes,  Alkermes)  is  a  corresponding  substance  to 
cochineal,  and  consists  of  the  dried  female  insects  Coccus  Ilicis,  which 
burrow  under  the  epidermis  of  the  leaves  or  young  shoots  of  the  kermes 
oak   (Quercus  coccifera),  growing  in  the  south  of  France,  Spain,  and 
Algeria.     The  coloring  matter  of  the  kermes  insect  has  not  been  suffi- 
ciently investigated;  it  is  said  to  be  identical  with  that  of  cochineal. 
It  is  not  used  any  longer  in  dyeing. 

8.  Lac  dye  (syn.  Farberlack)  is  the  product  of  the  Coccus  Lacca,  an 
East  Indian  insect  which  lives  on  the  branches  of  the  fig  and  other  trees. 
The  female  insects  exude  a  resinous  substance  which  encloses  them  and 
attaches  them  to  the  twig.     This  constitutes  the  "stick-lac"    (see  p. 
108),  which  contains  about  ten  per  cent,  of  coloring  matter.    This  latter 
may  be  obtained  by  treating  the  stick-lac  with  carbonate  of  soda.     The 
coloring  matter  of  lac  dye  has  been  studied  by  Schmidt,  who  terms  it 
laccainic  acid,  C1GH12OS,  and  found  it  to  be  very  similar  to  carminic 
acid  in  most  of  its  reactions.    Many  writers  consider  the  two  to  be 
identical. 

B.  YELLOW  DYES. 

1.  Old  Fustic  (syn.  Gelbholz,  Bois  jaune}  is  the  trunk  wood  of  Morus 
tinctoria,  indigenous  to  the  West  Indies  and  South  America.     It  is  also 
yielded  by  the  Madura  tinctoria  and  Broussonetia  tinctoria.     The  wood 
is  hard  and  compact  and  has  a  pale  citron-yellow  color.     It  contains 
two  coloring  principles,  morin,  or  moric  acid,  C15H10O7,  which  occurs  in 
the    wood    combined    with   lime,    and    maclurin,    or    moritannic     acid, 
C13H100C,  both  of  which  are  yellow  dyes  and  are  contained  in  the  com- 
mercial extract. 

2.  Young  Fustic   (syn.  Fisetholz,  Bois  de  fustet)    is  the  bark-free 
wood  of  the  Rhus  cotinus,  a  variety  of  sumach  growing  in  the  Levant, 
Spain,  Hungary,  Tyrol,  and  Italy.     The  coloring  matter  is  stated  by 
Schmidt  to  occur  as  a  soluble  compound  of  fustin  and  tannic  acid.    This 
fustin  is  a  glucoside,  and  is  decomposed  by  dilute  sulphuric  acid  into 
fisetin,  C15H10O6,  and  isodulcite.     A  decoction  of  young  fustic  .gives  a 
fine  orange  color  with  alkalies  and  bright  orange  precipitates  with  lime 
and  baryta-water,  stannous  chloride  and  lead  acetate.     It  also  gives  a 
fine  orange  color  with  alumina  mordants.     Is  largely  used  in  the  dyeing 
of  glove-leathers. 

3.  Quercitron  is  the  crushed  or  rasped  bark  of  the  Quercus  nigra 
or  Quercus  tinctoria,  indigenous  to  North  America,  and  grown  also  in 
Germany  and  France.     It  forms  a  brownish-yellow  powder,  from  which 
an  extract  is  also  made.     The  coloring  principle  is  quercitrin,  C21H22012, 
a  glucoside,  which  is  decomposed  by  dilute  sulphuric  acid  into  quercetin, 
C15Hj0O7,     and     isodulcite.     Besides     quercitm,     the     bark     contains 
quercitannic  acid,  C17H1006.     Quercitin  is  difficultly  soluble  in  water, 
but  easily  soluble  in  alkalies  with  golden-yellow  color.     '"Flavine  "  is 
the  commercial  name  of  a  preparation  of  quercitron  obtained  by  acting 
upon  the  bark  first  with  alkalies  and  treating  this  extract  with  sulphuric 


RAW  MATERIALS.  493 

acid;  it  is  a  varying  mixture  of  quercitrin  and  isodulcite,  having  some 
sixteen  times  the  coloring  power  of  the  bark. 

Flavine  and  quercitron  bark  are  used  chiefly  for  dyeing  cottons  and 
woollens  with  tin  mordants. 

4.  Persian  Berries,  or  Avignon  Berries    (syn.   Gelbbeeren,   Graines 
jaunes),  are  the  dried  fruit  of  different  buckthorn  (Rhamnus)  species. 
The   different   commercial   varieties   are  the   Persian    (from   Rhamnus 
amygdalinus  and  Rhamnus-oleo'idiis) ,  coming  from  Aleppo  and  Smyrna, 
regarded  as  the  richest  in  dye  color  and  the  best  in  use,  the  French,  or 
Avignon  (from  Rhamnus  infectoria  and  Rhammts  saxatilis),  the  Levan- 
tine, or  Turkish  (from  Rhamnus  infectoria  and  Rhamnus  saxatilis),  and 
the  Spanish  (from  Rhamnus  saxatilis}  and  the  Hungarian  (from  Rham- 
nus amygdalinus,  etc.). 

The  coloring  matter  of  the  Persian  berries  is  called  by  Liebermann 
xanthorhamnin,  or  chrysorhamnin,  and  is  a  glucoside,  yielding  under 
the  influence  of  dilute  acids  rhamnetin,  C16H1207  (or  methyl-quercetin, 
C18H,OTCH,),  and  isodulcite.  Persian  berries  are  used  for  yellows  on 
wool  and  cotton  with  alumina  or  tin  mordants. 

5.  Weld  (syn.  Wau,  Gelbkraut,  Gaude)   consists  of  the  leaves  and 
other  parts  of  the  Reseda  luteola,  a  variety  of  mignonette.     It  is  culti- 
vated in  almost  all  parts  of  Europe,  notably  in  the  south  of  France, 
Germany,   and   England.     The   coloring  matter  is  known   as   luteolin, 
Cir,H1006,  and  forms  yellow  crystals  of  silky  lustre,  insoluble  in  water, 
soluble  in  alcohol.     It  dissolves  in  alkalies  with  deep  yellow  color.     It 
is  used  especially  in  silk-dyeing. 

6.  Annatto   (syn.  Orlean,  or  Roucou)   is  prepared  from  the  fleshy 
pulp  of  the  seed-shells  of  the  Bixa  orellana,  indigenous  to  the  West 
Indies  and  South  America,  but  cultivated  also  in  the  East  Indies.     The 
commercial  annatto  forms  a  soft  reddish-yellow  paste  of  buttery  con- 
sistency, or  sometimes  it  is  dried  in  hard  cakes.     It  contains  two  color- 
ing matters,  bixin,  C28H34O5,  and  orellin,  the  former  of  which — the  more 
important — is  a  red  dye  and  the  latter  a  yellow.     The  bixin  dissolves  in 
alkalies  with  yellow  color.     It  is  but  little  used  in  silk-dyeing.     Orellin 
is  as  yet  only  slightly  studied,  and  is  considered  by  some  to  be  simply 
an  oxidation  product  of  bixin.     By  far  the  largest  amount  of  annatto 
is  used  not  in  dyeing  but  in  coloring  butter  and  cheese.     (See  p.  295.) 

7.  Turmeric  (syn.  Gelbwurz,  Curcuma)  is  the  tuber  of  the  Curcuma 
tinctoria  and  Curcuma  rotunda.     The  roots  are  usually  grayish-yellow 
on  the  exterior  but  deep  yellow  in  the  interior.     The  plant  is  indigenous 
to  Central  Asia.     The  varieties  of  it  are  the  Chinese,  Java,  and  Bengal, 
of  which  the  latter  is  considered  the  best.     The  coloring  principle  is 
curcumin,  C21H200(t,  which  acts  like  a  weak  acid.     The  pure  color  is 
bright  orange-red,  but  it  dissolves  in  alkalies  with  a  red-brown  color. 
It  is  seldom  used  as  a  dye,  and  then  only  for  shading  blacks  on  silk. 

C.  BLUE  DYES. 

1.  Indigo  (syn.  Indig-blau,  Indigo). — This  is  by  far  the  most  im- 
portant of  all  the  vegetable  dyes.  It  has  been  known  from  very  early 
times  in  the  East,  but  was  not  introduced  into  Europe  until  the  six- 


494  NATURAL  DYE-COLORS. 

teenth  century,  where  its  use  was  at  first  prohibited  because  of  the  gen- 
eral culture  of  the  woad,  and  indeed  it  was  only  in  1737  that  its  employ- 
ment was  legally  permitted  in  France.  However,  in  time  it  displaced 
the  woad  almost  entirely,  so  that  the  latter  is  used  now  only  in  a  few 
special  cases. 

The  indigo-plant  is  an  Indigofera,  the  more  important  varieties  of 
which  are  the  Indigofera  tinctoria,  cultivated  in  India,  particularly  in 
Bengal,  Coromandel,  Madras,  Java,  and  Manila;  the  Indigofera  Anil, 
cultivated  in  Guatemala,  Caracas,  Brazil,  and  the  Antilles;  the  Indigo- 
fera Argent  ea,  cultivated  in  Egypt,  Senegal,  and  the  Isle  of  France. 
Of  lesser  importance  are  the  Indigofera  disperma  and  the  Indigofera 
pseudotinctoria,  both  cultivated  in"  the  East  Indies.  The  Indigofera 
tinctoria  is  shown  in  Fig.  112  (see  p.  489)  to  the  left  of  the  illustration 
above.  The  indigo  dye  does  not  exist  as  such  in  the  plant  but  as  the 
result  of  fermentation,  whereby  the  naturally  occurring  indican,  a  glu- 
coside,  is  decomposed,  most  probably  according  to  the  reaction : 

2C26H31N017  +  4H20  =  C16H10N208  +  6C6H1006. 

Indican.  Wat°r.  Indigo-blue.  Indiglucin. 

The  plants  are  cut  at  two  or  three  different  periods  in  the  year  when 
they  have  just  come  into  bloom.  They  are  at  once  packed  into  bundles 
and  put  into  the  soaking-vats  covered  with  water.  A  fermentation  here 
ensues,  which  is  completed  in  from  ten  to  eighteen  hours,  according  to 
the  temperature  of  the  air  and  the  ripeness  of  the  plants.  When  the 
supernatant  liquid  has  taken  a  yellowish-green  color  and  has  a  pleasant 
sweetish  taste,  the  fermentation  is  stopped  and  the  liquid  is  run  off  into 
vats  placed  at  a  lower  level.  Here  it  is  beaten  vigorously  with  sticks  or 
paddles  for  from  one  and  a  half  to  three  hours  by  men  who  enter  the 
vats  for  the  purpose.  The  liquid  is  changed  by  this  treatment  to  a 
deep-blue  color  and  becomes  covered  with  froth  of  like  color.  When 
the  men  leave  the  vat  to  rest,  the  separated  indigo  rapidly  settles,  and 
in  some  two  to  three  hours  the  supernatant  liquid  can  be  run  off  from 
stopcocks  placed  in  the  side  of  the  vat  at  levels  above  the  indigo  pre- 
cipitate. Milk  of  lime  is  often  added  to  hasten  the  settling  of  the 
separated  indigo,  and  more  recently  dilute  ammonia  has  been  used. 
The  addition  of  this  latter  reagent  is  said  to  increase  the  yield  of 
indigo  and  to  improve  its  quality,  as  it  contains  less  indigo-brown  and 
resinous  impurities.  The  thin  paste  of  indigo  and  water  is  then  drawn 
off,  boiled  to  prevent  subsequent  fermentation,  and  strained  through  a 
sheet.  It  is  then  put  into  square  press-boxes  lined  with  cloth  and  pro- 
vided with  holes  in  the  sides  and  bottom  for  thorough  drainage  of  the 
indigo.  Pressure  is  then  applied,  gentle  at  first  but  stronger  as  the 
indigo  hardens  and  acquires  a  firmer  consistency.  The  mass  is  then 
cut  into  cubical  blocks,  which  are  stamped  with  the  name  of  the  factory 
and  put  on  shelves  in  the  drying-house  to  slowly  dry  out,  great  care 
being  taken  to  avoid  drafts  of  air,  which  might  cause  the  cakes  to  crack 
in  drying.  Three  hundred  kilos,  of  indigo-plants  yield  an  average  of 
one  kilo,  of  indigo.  The  commercial  product  contains  from  twenty  to 
eighty  per  cent,  of  the  indigo-blue  (averaging  about  forty-five  per  cent.), 


RAW  MATERIALS.  495 

and  with  this  two  other  coloring  matters,  indigo-brown  and  indigo-red, 
besides  'indigo-gluten,  moisture,  and  a  variable  amount  of  mineral 
matter. 

The  commercial  varieties  of  indigo  are,  first,  the  Asiatic,  of  which 
the  Bengal  indigo  is  the  best,  followed  by  the  Java,  Madras,  Coroman- 
del,  and  Manila  varieties;  second,  the  American,  of  which  the  Guate- 
mala is  the  best,  followed  by  the  Caracas  and  the  Brazilian  varieties; 
and,  third,  the  African,  including  the  Egyptian,  Senegal,  and  Isle  de 
France  varieties. 

Indigo-blue  is  insoluble  in  water,  alcohol,  ether,  dilute  acids,  and 
alkalies,  soluble  in  fuming  sulphuric  acid,  aniline,  nitrobenzene,  chloro- 
form, and  glacial  acetic  acid.  It  may  be  sublimed  by  heat,  although 
with  partial  decomposition  when  the  sublimation  is  carried  out  at  ordi- 
nary atmospheric  pressure.  By  the  action  of  alkaline  reducing  agents 
it  is  changed  to  indigo-white,  C16H12N202,  and  dissolved.  Upon  this 
reaction  and  the  subsequent  change  of  the  indigo-white,  when  deposited 
upon  the  textile  fibre,  by  atmospheric  oxidation  back  again  into  indigo- 
blue,  is  based  the  use  of  indigo  in  vat-dyeing.  (See  p.  536.)  Indigo 
has  been  extensively  used  for  cotton  and  wool  dyeing,  but  is  being  largely 
replaced  by  the  artificial  indigo. 

2.  Woad   (syn.   Waid,  Pastel). — The  leaves  of  the  Isatis  tinctoria 
and  Isatis  lusitanica  moistened,  slightly  fermented,  and  then  compacted 
and  dried  into  balls  constitute  the  woad  of  commerce  and  furnish  an 
additional  source  of  indigo.     As  before  stated,  the  use  of  the  woad  for 
dyeing  antedated  the  use  of  the  indigo-plant,  and  the  cultivators  of  the 
woad,  particularly  in  Central  Germany,  long  fought  against  the  intro- 
duction of  the  richer  tropical  indigo-yielding  material,  but  in  vain.    The 
woad-culture  is  still  carried  on  in  different  parts  of  Europe,  particularly 
in  France  and  Germany,  but  in  small  degree  compared  with  its  former 
development.     The  woad  contains  only  .3  per  cent,  of  indigo  reckoned 
on  the  weight  of  the  fresh  leaves,  or  as  it  is  often  calculated,  one  hun- 
dred kilos,  of  woad  have  the  same  coloring  power  as  two  kilos,  of  indigo. 
The  woad  balls  improve  in  quality  by  keeping  for  some  years,  the  best 
variety  coming  from  the  south  of  France  under  the  name  of  Pastel. 
The  woad  is  rarely  used  by  itself  in  dyeing  operations,  but  along  with 
indigo  as  a  means  of  inciting  the  fermentation  in  the  "  woad- vat  " 
process  of  dyeing. 

A  few  other  plants,  such  as  Polygonum  tinctorium,  indigenous  to 
China,  and  Eupatorium  tinctorium,  indigenous  to  Brazil,  have  been 
found  to  contain  indigo,  and  have  been  used  locally  for  blue-dyeing. 

3.  Logwood  (syn.  Blauholz,  Bois  de  Campeche). — This  is  the  heart- 
wood,  freed  from  bark  and  sap-wood,  of    the    Hcematoxylon    Campe- 
chianum,  a  tree  indigenous  to  Campeachy  Bay,  Central  America,  but 
grown  now  in  various  parts  of  Central  and  South  America  and  the 
West  Indies.     The  commercial  varieties  are  the  Campeachy,  Yucatan, 
Laguna,  Honduras,  Jamaica,  Haiti,  St.  Domingo,  Monte  Christo,  Fort 
Liberte,  and  Guadeloupe  logwoods.     The    principal    sources    now    are 
Jamaica,  Haiti,  and  St.  Domingo. 

Of  these,  the  first  commands  the  highest  price  on  account  of  the 


496  NATURAL  DYE-COLORS. 

large  yield  of  coloring  matter  obtainable  from  it  and  the  readiness  with 
which  it  "  bronzes  "  when  submitted  to  the  "  curing  "  process.  The 
wood  comes  in  logs  or  sticks  of  smaller  size,  and  is  then  chipped  or 
rasped  by  the  makers  of  extracts,  who  sell  it  in  the  chipped  or  rasped 
condition  as  well  as  in  the  form  of  prepared  extract.  The  wood  has  a 
dark-red  color  on  the  exterior  but  is  yellowish-red  in  the  interior,  has  a 
weak  odor  of  violets  and  a  peculiar  sweetish  but  astringent  taste.  On 
moistening  the  wood  or  chips  with  ammonia  it  takes  a  dark-violet  color. 
Logwood  contains  some  nine  to  twelve  per  cent,  of  the  chromogen, 
hcBmatoxylin,  C16H14O6,  which  is  present  in  the  wood  partly  in  the  free 
state  but  mainly  as  glucoside.  It  forms  colorless  prismatic  crystals 
difficultly  soluble  in  water,  easily  soluble  in  alcohol  and  ether.  From 
the  hasmatoxylin  by  oxidation  in  the  presence  of  alkalies,  and  particu- 
larly ammonia,  is  produced  hcematein,  C1GH12O5,  the  true  dye-color. 
This  forms  small  crystals  or  crystalline  scales  of  dark-red  color  and 
greenish  metallic  lustre,  which  show  plainly  upon  the  wood,  especially 
after  the  fermentation  or  curing.  It  is  difficultly  soluble  in  water, 
alcohol,  and  ether.  Hgematein  forms  a  crystalline  compound  with 
ammonia,  C16H11(NH4)O6  -f  H20,  which,  however,  is  decomposed  by 
acids  or  by  heating  to  130°  C.,  leaving  pure  hoematein.  Zinc  and  sul- 
phuric acid  readily  reduce  the  hcematein  to  hasmatoxylin  again.  Log- 
wood is  used  on  an  extended  scale  in  dyeing  wool,  silk,  cotton,  and 
leather.  It  is  used  for  deep  blues,  blacks,  and  jointly  with  other  color- 
ing matters  for  composite  shades  of  color. 

4.  Litmus  (syn.  Lakmus,  Tournesol). — This  is  a  dyestuff  very  simi- 
lar in  character  to  orseille  and  persio  (see  p.  491),  and  also  derived  from 
the  class  of  lichens.  For  its  preparation  the  same  lichens  may  be  used, 
although  at  present  the  different  species  of  Lecanora  serve  as  the  chief 
material,  such  as  Lecanora  orcina,  L.  dealbata,  L.  parella,  which  occur 
in  the  French  Pyrenees,  and  the  Lecanora  tartarea,  occurring  in  Iceland 
and  Scandinavia.  The  lichens  are  allowed  to  ferment  after  the  addi- 
tion of  stale  urine  or  ammonia  and  carbonate  of  potash.  When  the 
mass  has  assumed  a  deep-blue  color,  chalk  or  gypsum  is  added,  and 
it  is  shaped  into  small  cubes  and  dried.  The  coloring  matter  is 
azolitmin,  C7H7N04,  which  differs  by  one  atom  of  oxygen  only  from  the 
orcein  of  orseille  extract,  C7H7N03.  It  acts  like  a  weak  acid,  the  salts 
of  which  are  blue  in  color  (the  potassium  compound  existing  in  the  com- 
mercial litmus),  and  which  when  set  free  by  acids  is  reddish  in  color. 

D.  GREEN  DYES. 

We  have  practically  nothing  here  that  has  assumed  practical  value 
as  yet.  The  only  ones  needing  mention  at  all  are : 

1.  Chlorophyll. — This  is  the  green  coloring  matter  of  fresh  vegeta- 
tion, and  is  abundantly  present  in  nature,  but  it  has  not  been  found 
possible  hitherto  to  isolate  it  in  a  pure  state  adapted  for  use.  Schiitz 
has,  however,  separated  it  from  the  yellow  coloring  matter  accompany- 
ing it,  xanthophyll.  It  is  stated  that  chlorophyll  forms  a  beautiful  green 
color  with  zinc  as  mordant  which  is  adapted  for  dyeing,  but  it  has  not 
as  yet  been  used  in  practice. 


PROCESSES  OF  TREATMENT.  497 

2.  Lokao,  or  Chinese  Green,  is  a  green  pulverulent  deposit  from  the 
decoction  of  the  bark  of  Rhamnus  chlorophorus  and  Rliamnus  utilis, 
both  indigenous  to  China.  Kayser,  who  has  investigated  the  lokao,  states 
that  the  coloring  matter  is  lokaonic  acid,  C42H48O27,  which  is  combined 
in  the  commercial  preparation  as  the  alumina  lake.  This  lokaonic  acid 
is  decomposed  by  acids  into  lokanic  acid,  C3BH36021,  and  lokaose,  an  in- 
active sugar.  Lokao  has  been  used  for  cotton-  and  silk-dyeing,  but  is 
practically  displaced  by  the  cheaper  artificial  colors. 

E.  BROWN  DYES. 

1.  Catechu  (or  Cutch). — This  has  already  been  spoken  of  as  one  of 
the  raw  materials  of  the  tanning  industry.      (See  p.  359.)      It  finds, 
however,  an  equally  extended  use  in  dyeing  as  an  adjective  color.     The 
explanation  of  this  is  that  catechu  contains  two  principles,  catechin, 
C^H^Og  -f-  5H2O,  a  yellow  dye  forming  brown  precipitates  with  copper, 
alumina,   and   tin   mordants,   and   catechutannic   acid,   C13H12O5.     The 
former  is  present  in  amount  from  twenty  to  thirty  per  cent.,  the  latter, 
however,  from  forty-eight  to  fifty-two  per  cent.     The  best  variety  of 
catechu  is  the  Pegu  catechu,  and  after  this  the  Bombay  and  the  Bengal 
catechu.     Catechu  is  extensively  used  in  both  cotton-  and  silk-dyeing 
for  browns  and  for  composite  shades. 

2.  Kino  is  a  natural  dyestuff  very  similar  to  catechu  and  comes  from 
a  variety  of  sources,  as  Butea  frondosa  and  Butea  superba,  yielding  the 
Bengal  kino;  Pterocarpus  erinaceus,  yielding  the  West  African  kino; 
Eucalyptus  corymbosa  and  other  Eucalyptus  species,  yielding  the  Aus- 
tralian kino.     The  important  principles  are  kinoin,  C14H1206,  and  its 
anhydride,  kino-red,  C^H^On.     It  is  used  like  catechu  for  dyeing. 

n.  Processes  of  Treatment. 

1.  CUTTING  OF  DYE-WOODS. — Whether  the  dye-woods  are  to  be  used 
for  the  manufacture  of  extracts  or  used  as  wood  by  the  dyer,  they  must 
be  reduced  to  powder  or  cut  into  chips  of  small  size.  This  process 
varies  with  different  manufacturers.  In  America,  it  is  usually  one 
of  cutting  with  powerful  knives,  in  which  whole  logs  are  brought  with 
their  ends  against  rapidly-revolving  cylinders,  on  the  circumference  of 
which  are  heavy  steel  knives,  which  cut  off  flat  chips  directly  across  the 
grain  about  one-eighth  inch  in  thickness.  This  method  is  a  very  rapid 
one,  as  but  little  previous  splitting  of  the  logs  is  necessary.  In  Europe, 
where  labor  is  cheaper,  the  logs  are  frequently  sawed  and  split  into 
billets  about  two  feet  long,  and  two  to  three  inches  in  thickness,  and 
these  are  then  brought  by  hand  diagonally  against  toothed  knives  on  a 
rapidly-revolving  cylinder,  by  which  means  the  wood  is  torn  or  rasped 
into  a  much  finer  condition,  or  these  billets  are  put  into  a  machine  which 
presses  them  in  this  way  against  the  revolving  knives.  Such  a  machine 
of  German  design  is  shown  in  Fig.  113,  where  a  rotating  drum,  D,  carry- 
ing on  its  circumference  a  series  of  knife-blades,  is  continuously  cutting 
the  billets  of  wood  which  are  pressed  against  it. 

32 


498 


NATURAL  DYE-COLORS. 


2.  FERMENTATION  OR  CURING  OF  DYE-WOODS. — As  has  already  been 
stated  in  several  cases,  the  dye-woods  in  the  fresh  condition  contain  not 
the  finished  dye-color,  but  a  chrom-ogen  capable  of  passing  into  the 
former  under  the  influence  of  oxidizing  or  other  agents.  Notably  is  this 
the  case  with  logwood,  and  the  chips  or  rasped  wood  are  therefore  sub- 
mitted to  a  curing  treatment  by  moistening  them  with  water  and  expos- 


FIG.  113. 


ing  them  to  the  air  in  heaps  some  three  feet  in  depth  for  from  four  to 
six  weeks.  The  chips  heat  up,  and  the  pile  must  then  be  turned  with 
shovels  to  regulate  the  temperature  and  allow  contact  with  the  air. 
More  water  is  then  added,  and  the  process  continued  until  the  chips 
assume  a  rich  reddish-brown  color  or  become  coated  with  a  bronze  pow- 
der (haematein).  Various  chemicals  have  been  suggested  to  hasten  the 
operation,  such  as  ammonium  carbonate  and  chloride,  stale  urine,  sodium 
carbonate,  potassium  nitrate,  chalk,  and  glue.  None  of  these  are  known 
certainly  to  be  of  benefit.  The  alkalies  give  the  chips  a  fine  red  color  at 
first,  but  unless  great  care  is  taken  they  cause  them  to  become  black  from 


PROCESSES  OF  TREATMENT. 


499 


over-oxidation  before  the  action  can  be  checked.     Glue  has  been  used 
because  it  is  said  to  combine  with  the  tannin  of  the  wood,  and  by  remov- 

FIG.  114. 


500  NATURAL  DYE-COLORS. 

ing  it  to  open  up  the  pores  of  the  wood  to  the  oxidizing  influence  and 
so  facilitate  the  curing.  But  the  existence  of  tannin  in  logwood  has  not 
been  at  all  certainly  established. 

Curing  is  of  value  to  the  dyer  because  it  enables  him  to  rapidly 
obtain  the  color  from  the  chips  and  gives  him  a  liquor  containing  a  more 
highly  oxidized  coloring  matter,  which  "  goes  on  "  the  goods  more  rap- 
idly. It  must  be  remembered,  however,  that  curing  the  chips  enables 
the  manufacturer  to  sell  twenty  to  thirty  per  cent,  of  water  with  them, 
while  uncured  chips  contain  only  ten  to  fifteen  per  cent,  of  moisture. 

"When  the  chipped  logwood  is  intended  for  the  manufacture  of  ex- 
tract it  is  usually  conveyed  directly  to  the  extractors  without  curing, 
which  is,  no  doubt,  the  better  procedure,  since  all  oxidation  in  the  first 
part  of  the  process  is  objectionable. 

3.  MANUFACTURE  OF  DYE-WOOD  EXTRACTS. — As  dye-woods  contain 
generally  only  a  tenth  or  less  of  their  weight  of  dye-color,  it  becomes  a 
matter  of  great  economy  in  transportation  and  storage  to  prepare  from 
them  extracts,  either  as  concentrated  liquids  or  solids  representing  the 
active  coloring  principle.  This  is  done  by  manufacturers  who  make  a 
specialty  of  this  extracting,  and  apply  to  it  the  best  designed  and  most 
improved  machinery. 

The  operation  may  be  divided  into  two  stages, — the  extraction  and 
the  concentration.  For  extraction  a  rasped  wood  such  as  is  made  in 
France  has  many  advantages  over  the  chipped,  since  it  yields  its  color- 
ing to  a  smaller  quantity  of  water  and  at  a  lower  temperature  than  the 
chips.  The  extraction  consists  in  heating  the  wood  with  water  under 
various  conditions  and  then  drawing  off  the  liquor  into  tanks  for  set- 
tling or  treatment.  The  conditions  refer  to  the  kind  of  vessels,  the 
amount  and  quality  of  the  water,  and  the  temperature.  Many  European 
manufacturers  use  open  wooden  vessels  for  extractors,  so  that  the  tem- 
perature does  not  get  above  100°  C.  As  this  method  was  first  used  in 
France,  it  is  known  as  the  French  process.  The  use  of  closed  extractors, 
however,  allows  of  increase  in  the  pressure,  and  this  within  limits  much 
facilitates  the  perfect  extraction.  A  closed  extractor  of  German  de- 
sign, in  which  a  pressure  not  exceeding  two  atmospheres  is  used,  is 
shown  in  Fig.  114.  (See  preceding  page.)  It  will  be  seen  that  the 
vessel,  A,  is  provided  with  a  false  bottom,  D,  to  allow  of  the  draining 
off  the  extract  liquor,  a  perforated  steam-pipe,  g,  to  rapidly  bring  up  the 
contents  of  the  extractor  to  the  required  temperature,  and  a  drainage- 
pipe,  h,  to  draw  off  the  thin  extraction  liquors. 

In  America  closed  copper  or  iron  vessels  are  used,  arranged  in  bat- 
tery form  very  much  like  the  diffusion  apparatus  now  used  in  the  ex- 
traction of  sugar.  One  cell  of  such  an  extraction  battery  is  shown  in 
Fig.  115.  This  method  allows  of  continuous  working,  as  one  cell  of  the 
series  can  be  emptied  of  exhausted  dye-wood  and  loaded  with  fresh 
chips  while  the  extraction  liquors  are  passing  successively  through  the 
other  cells  of  the  battery  and  acquiring  the  maximum  strength.  The 
temperature  or  pressure  varies  with  different  manufacturers,  but  most 
writers  on  the  subject  agree  that  a  pressure  not  exceeding  fifteen  to 


PROCESSES  OF  TREATMENT. 


501 


FIG.  115. 


twenty  pounds  excess  over  atmospheric  pressure  should  be  used.  An 
increase  in  the  pressure  is  always  attended  with  an  increase  in  the  yield, 
and  after  a  certain  point  with  a  decrease  in  the  coloring  value  of  the 
resulting  extract.  When  the  liquors  from  the  extractors  are  run  into 
large  tanks  and  allowed  to  cool  much  wood-fibre  and  some  resinous  mat- 
ter separates.  The  clear  liquor  is  then  drawn  into  the  evaporators,  which 
in  this  country  almost  invariably  consist  of  vacuum-pans,  but  in  Europe 
often  consist  of  open  pans  or  vessels  in 
which  heated  disks  revolve  so  as  to  favor 
the  evaporation.  While  the  liquor  is 
still  thin,  double-  or  triple-effect  pans 
are  used,  and  of  recent  years  the 
Yaryan  evaporators  (see  Fig.  38,  p. 
144)  have  been  applied  with  great  suc- 
cess to  the  evaporation  of  dye-wcod  ex- 
tracts. As  the  liquors  become  thicker 
the  concentration  is  continued  in 
vacuum-pans  more  analogous  to  the 
strike-pans  of  the  sugar  refinery.  Such 
a  vacuum-pan  designed  for  use  in  the 
manufacture  of  dye-wood  extracts  is 
shown  in  Fig.  116.  When  the  gravity 
of  the  liquid  becomes  42°  or  51°  Tw.,  it 
is  drawn  off  into  barrels  for  shipment,  or 
if  the  solid  extract  is  desired  the  concen- 
tration is  continued  in  a  vacuum-pan. 

Various  methods  of  treatment  have 
been  suggested  at  different  stages  of  the 
process  with  a  view  of  improving  the 
extract,  but  it  is  an  open  question 
whether  anything  better  than  pure  water 
has  yet  been  used.  The  addition  of  solu- 
tions of  glue  and  of  different  salts  to 
the  wood  before  extraction  has  been 
frequently  recommended.  Chalk  sus- 
pended in  water  and  dilute  lime- 
water  have  also  been  recommended  to 
be  similarly  used.  Such  processes  could  only  result  in  an  over-oxidized 
product.  Borax  has  also  been  used,  but  without  notable  advantage  in 
the  case  of  logwood,  although  it  serves  very  well  in  the  case  of  the  red- 
woods. The  use  of  chlorine,  hypochlorites,  and  chlorates  has  been 
patented  in  connection  with  logwood  extract  for  addition  either  to  the 
wood  or  the  liquor  after  extraction,  but  it  is  doubtful  if  any  of  these 
are  used  on  a  large  scale  at  the  present  time.  That  these  substances 
and  many  others  develop  the  color  of  logwood  there  can  be  no  ques- 
tion, but  to  be  of  value  to  the  dyer  that  development  must  take  place  in 
the  presence  of  the  goods. 

The  yield  of  logwood  extract  by  the  American  process  of  manufac- 


502 


NATURAL  DYE-COLORS. 


ture  is  said  by  Soxhlet*  to  be  twenty  or  twenty-one  per  cent,  of  solid 
extract,  while  that  by  the  French  process  is  sixteen  and  a  half  per  cent. 
The  latter  is  superior  in  quality,  and  is  therefore  almost  invariably  re- 
duced by  the  addition  of  such  substances  as  molasses,  glucose,  and  ex- 
tract of  chestnut.  In  America,  in  addition  to  the  above,  extract  of 


FIG.  116. 


hemlock  and  extract  of  quercitron  (after  the  removal  of  the  flavine)  are 
considerably  used  to  adulterate  logwood  extract. 

4.  MISCELLANEOUS  PROCESSES. — (a)  Preparation  of  Guarancine  and 
Madder  Flowers. — For  the  preparation  of  guarancine,  the  pulverized 
madder-root  is  warmed  gently  with  dilute  sulphuric  acid  (one  part  acid 
and  two  parts  water)  for  some  time,  whereby  the  glucosides  of  the 
madder  are  decomposed.  The  sugary  liquid  is  drained  off  and  the  resi- 

*  Textile  Colorist,  xiii,  p.  125. 


PROCESSES  OF  TREATMENT.  503 

due  heated  with  concentrated  sulphuric  acid,  which  decomposes  the 
woody  fibre  and  other  organic  substances  present  and  decomposes  any 
lime  compounds  that  may  have  been  in  the  madder.  The  whole  mixture 
is  now  thrown  into  water,  the  precipitate  collected,  washed,  and  dried. 
The  guarancine  now  contains  the  alizarin  and  purpurin  in  uncombined 
form.  The  yield  is  from  thirty-four  to  thirty-seven  per  cent.  For  the 
preparation  of  ."  madder  flowers  "  the  powdered  madder  is  set  to  fer- 
ment with  warm  water  to  which  a  little  dilute  sulphuric  acid  had 
been  added.  After  some  days,  the  liquid  is  filtered  and  the  residue 
washed,  pressed,  and  dried.  The  flowers  of  madder  can  be  used  more 
readily  than  crude  madder  in  dyeing  at  low  temperatures,  and  give  finer 
and  purer  violets. 

(&)  Preparation  of  Ammoniacal  Cochineal  and  Carmine. — Five  parts 
of  powdered  cochineal  are  mixed  with  fifteen  parts  of  ammonia-water, 
and  the  mixture  is  allowed  to  stand  in  a  warm  place  with  frequent  stir- 
ring for  some  four  weeks.  Some  two  parts  of  alumina  are  then  added, 
and  the  mixture  carefully  evaporated  in  a  porcelain  dish  until  the  odor 
of  ammonia  has  disappeared.  The  preparation  so  obtained,  known  as 
ammoniacal  cochineal,  yields  its  color  more  readily  than  cochineal  and 
produces  brighter  shades  of  color. 

Cochineal-carmine  is  a  brilliant  red  pigment  prepared  from  decoc- 
tion of  cochineal  by  the  action  of  alum  under  certain  conditions.  The 
details  of  its  preparation  vary  and  are  kept  by  different  manufacturers 
as  trade  secrets.  The  following  process  has  been  published :  *  Five 
hundred  grammes  of  finely-powdered  cochineal  are  boiled  for  one-quar- 
ter of  an  hour  with  thirty  times  the  weight  of  distilled  water,  thirty 
grammes  of  acid  tartrate  of  potassium  added,  boiled  for  ten  minutes 
longer,  fifteen  grammes  of  alum  added  and  boiled  for  two  minutes 
longer.  The  clear  liquid  is  allowed  to  stand  in  shallow  glass  vessels,  when 
the  carmine  separates  in  a  very  fine  state.  It  is  washed  with  water 
and  dried  in  the  shade.  Or,  by  another  process,  f  one  pound  of  cochineal 
and  one-half  ounce  of  potassium  carbonate  are  boiled  with  seven  gallons 
of  water  for  fifteen  minutes.  The  heat  having  been  withdrawn,  one 
ounce  of  powdered  alum  is  added,  and  the  liquid  stirred  and  allowed 
to  settle.  The  clear  liquid  is  decanted,  one-half  ounce  of  isinglass  added, 
and  heat  applied  until  a  coagulum  forms,  when  the  liquid  is  briskly 
stirred  and  allowed  to  settle. 

(c)  Preparation  of  Flavine. — As  stated  before  (see  p.  492),  flavine 
is  a  preparation  containing  the  coloring  matter  of  the  quercitron  bark 
in  purer  and  more  concentrated  form.  The  method  for  its  preparation 
is  not  generally  known,  although  it  is  found  to  contain  quercetin  as 
well  as  quercitrin,  and  frequently  the  former  in  larger  amount. 

A  procedure  that  has  been  published  J  is  the  following :    Two  hun- 

*  Schiitzenberger,  Die  Farbstoffe,  ii,  p.  338. 

f  Allen,  Commercial  Organic  Analysis,  2d  ed.,  iii,  p.  367. 

j  Gerb-  und  Farbstoffe-Extracte,  Mierzinski,  p.  208. 


504  NATURAL  DYE-COLORS. 

dred  and  fifty  kilos,  of  the  powdered  quercitron  are  boiled  for  fifteen 
minutes  with,  fifteen  kilos,  of  crystallized  soda  and  two  hundred  kilos, 
of  water,  there  is  then  added  to  the  liquid  sixty-one  kilos,  of  sulphuric 
acid  of  66°  B.,  and  the  boiling  continued  for  three-quarters  of  an  hour 
longer,  when  the  whole  is  allowed  to  cool  and  settle,  the  liquid  poured 
off,  and  the  separated  color  drained  and  dried. 

(d)  Preparation  of  Indigo-carmine,  Soluble  Indigo,  etc. — It  was 
stated  in  an  earlier  section  (see  p.  495)  that  indigo-blue  was  soluble 
in  strong  sulphuric  acid.  The  solubility  depends,  however,  upon  the 
chemical  action  of  the  acid,  whereby  sulphonic  acids  of  indigo  are 
formed.  Two  such  acids,  indigo-monosulphonic  acid  (sulpho-purpuric 
acid),  C1CH9(HS03)N2O2,  and  indigo-disulphonic  acid  (sulphindigotic 
acid),  C16H8(HS03)2N202,  are  formed.  Of  these,  the  first  is  insoluble 
in  water  or  dilute  acids,  while  the  second  is  soluble  with  deep-blue  color. 
Both  are  formed  together  in  practice  when  indigo  is  dissolved  in  strong 
sulphuric  acid,  although  if  not  more  than  four  parts  of  sulphuric  acid  to 
one  of  indigo  be  used  and  too  prolonged  heating  be  avoided,  the  mono- 
sulphonic  acid  will  be  formed  predominantly,  while  if  some  fifteen  parts 
of  ordinary  concentrated  sulphuric  acid  or  seven  parts  of  fuming  sul- 
phuric acid  be  taken  to  one  of  indigo  and  the  heating  be  continued,  the 
disulphonic  acid  will  be  the  sole  product.  After  treatment  with  the 
acid  the  dissolved  mass  of  indigo  is  allowed  to  cool  down  and  then 
strained  to  remove  any  lumps  that  may  have  escaped  grinding;  salt  is 
thrown  in,  which  precipitates  the  indigo-sulphonic  acids,  which  are  re- 
moved by  filtration  through  felt.  For  finer  grades  of  "  indigo  ex- 
tract "  the  precipitate  is  redissolved  in  water  and  reprecipitated  with 
salt  several  times,  each  precipitation  removing  a  greater  quantity  of 
the  objectionable  green  coloring-matter.  Whatever  be  the  process  or 
proportion  of  acid  used,  the  indigo  must  be  very  finely  ground.  This 
is  done  in  indigo-mills,  which  are  of  various  forms,  known  as  "  ball- 
mills,"  in  which  rotating  cannon-balls  gradually  grind  the  color,  as 
"  cylinder-mills,"  in  which  heavy  iron  rolls  accomplish  the  same  work, 
and  other  forms.  An  illustration  of  such  an  indigo-mill  with  conical 
rolls,  taken  from  a  form  in  current  use,  is  shown  in  Fig.  117.  Indigo 
grinding  for  "  extract  "  making  is  of  little  importance  since  the  intro- 
duction of  dry  synthetic  indigo.  The  direct  use  for  dyeing  of  the 
product  obtained  by  the  action  of  sulphuric  acid  upon  indigo  is  no  longer 
common.  The  preparation  and  sale  by  the  color  manufacturers  of  pure 
preparations,  known  as  Indigo  Extract,  Soluble  Indigo,  or  Indigo- 
carmine,  has  replaced  them.  The  sodium  salt  of  the  monosulphonic  acid 
constitutes  "  indigo-purple  "  or  "  red  indigo-carmine,"  the  sodium  salt 
of  the  disulphonic  acid  the  true  "  indigo-carmine,"  which  comes  into 
commerce  in  paste  form  under  that  name  or  as  a  dry  powder  known  as 
"  Indigotin." 

This  indigo-disulphonic  acid  fixes  itself  on  the  animal  fibre  like  other 
acid  colors,  and  is  dyed  in  an  acid  bath  containing  sulphuric  acid. 


PRODUCTS. 
m.  Products. 


505 


1.  FROM  RED  DYESTUFFS. — (a)  Brazil-wood  Extracts  are  made  by 
the  diffusion  process,  three  varieties  coming  into  commerce, — a  liquid 
extract  of  20°  B.,  a  liquid  one  of  30°  B.,  and  a  solid  one.  One  kilo, 
of  the  dry  extract  corresponds  on  the  average  to  twelve  kilos,  of  the 
wood.  Brasilin  is  also  manufactured  on  a  large  scale  almost  pure  by 
Geigy,  of  Basle. 

This  brasilin  often  separates  in  the  form  of  a  crystalline  crust  on 
the  surface  of  the  commercial  extract  liquors.  These  crusts  contain  the 

FIG.  117. 


brasilin  mixed  with  the  lime  compound  of  the  same.  If  this  crude 
product  is  boiled  with  very  dilute  alcohol  with  the  addition  of  zinc  dust 
and  hydrochloric  acid,  and  the  solution  stood  aside  to  crystallize,  a  very 
pure  product  is  obtained. 

Brasilin  is  relatively  easily  soluble  in  water,  alcohol,  and  ether.  In 
alkalies  it  is  soluble  with  carmine-red  color.  Zinc  dust  will  decolorize 
the  solution,  but  on  exposure  to  the  air  it  speedily  takes  up  the  red 
color  again.  Acetate  of  lead  precipitates  a  colorless  crystalline  com- 
pound which  gradually  turns  red.  Brasilein  bears  the  same  relation  to 
brasilin  that  hsematein  bears  to  hsematoxylm,  and  can  be  prepared  by  the 
oxidation  of  the  alkaline  solution  of  brasilin  in  the  air. 

Brazil-wood  extracts  are  used  in  wool-  and  cotton-dyeing.  With 
alumina  mordants  they  produce  shades  resembling  the  alizarin  lakes, 


506  NATURAL  DYE-COLORS. 

but  inferior  in  character.  On  wool  mordanted  with  bichromate  of 
potash  they  produce  a  fine  brown. 

The  insolubility  of  the  coloring  matters  in  sandal-wood  prevents 
their  being  used  in  the  form  of  extracts. 

(6)  Madder  Preparations. — We  have  already  referred  to  Quarantine 
and  Flowers  of  Madder.  Guaranceux  is  the  name  applied  to  the  impure 
purpurin  recovered  from  the  sediment  of  the  waste-liquors  in  madder- 
dyeing. 

Pincoffin  (Alizarine  commerciale)  is  a  preparation  from  guarancine, 
in  which  the  purpurin  has  been  decomposed  by  superheated  steam,  leav- 
ing the  alizarin  unchanged.  It  has  twenty-five  per  cent,  less  coloring 
power  than  the  guarancine,  but  gives  finer  violets  than  can  be  obtained 
with  the  former. 

(c)  Safflower  Preparations. — These  are  practically  more  or  less  pure 
preparations  of  carthamin,  and  the  names  Safflower  Extract,  Safflower- 
carmine.  Safflower-red,  and  Plate-red  refer  to  different  concentrations  of 
the  carthamin  solution.     For  the  preparation  of  the  pure  safflower-red, 
the  safflower-yellow  must  be  removed  by  washing  the  crushed  flowers 
with  water  until  this  runs  off  colorless.     The  residue  is  then  treated  with 
water  and  fifteen  per  cent,  of  its  weight  of  crystallized  soda  salt.     The 
solution  is  strained  from  the  residue,  filtered,  and  after  acidulating  with 
acetic  or  citric  acid,  cotton  yarn  is  immersed  in  it  to  take  up  the  color. 
The  dyed  cotton  is  stripped  of  the  color  by  a  five  per  cent,  soda  solution, 
and  from  this  solution  the  color  is  again  precipitated  by  citric  acid.     It 
is  now  drained,  and  comes  into  commerce  as  a  paste  known  as  ' '  Safflower 
Extract."     The  color  must  be  kept  in  sealed  flasks,  protected  from  the 
light.     This  paste  dried  upon  plates  at  a  gentle  heat  yields  the  so-called 
"  plate-red."     It  then  forms  a  red  powder  with  greenish  reflex,  almost 
insoluble  in  water  and  ether,  but  easily  soluble  in  alcohol.     It  is  also 
soluble  in  alkalies  with  yellowish-red  color.     The  "  safflower-carmine, " 
on  the  other  hand,  is  prepared  from  the  extract  paste  by  washing  the 
insoluble  color  and  dissolving  it  in  alcohol,  which  is  then  left  to  slowly 
evaporate.     For  dyeing  purposes  the  safflower-carmine  is  dissolved  by 
addition  of  soda,  and  the  bath  is  then  made  slightly  acid  with  citric 
acid;  or  the  soda-extraction  liquors  from  the  flowers,  which  have  been 
washed  with  water,  may  be  used  directly,  acidifying  the  bath  as  before. 
Safflower-red  is  fixed  in  a  weak  acid  bath  both  upon  the  animal  fibre  and 
upon  the  unmordanted  cotton.     On  silk  it  produces  a  fine  rose-red  color. 

(d)  Orseitte  Preparations. — These  come  into  commerce  both  as  paste 
and  liquor.     The  solid  matter  consists  essentially  of  the  impure  orcein 
in  combination  with  ammonia.     It  is  liable  to  be  adulterated  with  the 
spent  weeds  from  the  manufacture  of  the  orseille  liquor  or  with  other 
vegetable  coloring  matters.     It  is  also  at  times  adulterated  with  aniline 
dyes,  such  as  magenta,  acid  magenta,  and  methyl  violet.     Various  azo 
dyes,  producing  colors  ranging  from  crimson  to  claret-red,  are  now  sold 
as  substitutes  for  the  orseille  extract,  and,  being  cheaper,  are  used  to 
adulterate  it.     These   are   known   as   "  orchil   extract,"   "  orchil-red," 
' '  orselline, "   etc.      They  may  be   detected  when   so   admixed   by  their 


PRODUCTS.  507 

behavior  with  salt  solution  and  basic  acetate  of  lead.  The  liquid  extract 
is  usually  brought  to  25°  B.,  and  is  frequently  adulterated  with  logwood 
or  Brazil-wood  extract.  Orseille  Purple  (French  Purple)  is  a  pure 
orseille  dye,  obtained  by  extraction  of  the  lichens  with  a  fifteen  per  cent, 
ammonia  solution,  precipitation  with  hydrochloric  or  sulphuric  acid, 
and  redissolving  in  ammonia.  This  solution  is  then  left  exposed  to  the 
air  in  shallow  vessels  until  it  becomes  dark  purplish-violet.  The  color 
is  then  precipitated  by  addition  of  sulphuric  acid,  washed,  and  dried. 
Orseille  Carmine  is  a  similar  preparation,  in  which  the  ammoniacal  solu- 
tion, after  exposure  to  the  air  until  it  becomes  cherry-red,  is  heated 
with  alum  or  calcium  chloride.  Cudbear,  or  Persia,  as  before  stated, 
is  a  dry  powder  obtained  by  evaporation  of  the  extract,  or  prepared 
direct  from  the  lichens  by  the  action  of  ammonia  or  urine  and  then 
evaporated  to  the  condition  of  a  powder.  It  is  often  adulterated  with 
common  salt  and  other  mineral  matters,  and  is  liable  to  much  the  same 
organic  impurities  or  adulterants  as  orseille. 

(e)  Cochineal  Preparations. — Ammoniacal  cochineal  and  cochineal- 
carmine  have  already  been  referred  to.  Ammoniacal  Cochineal  is  dis- 
tinguished from  carminic  acid  by  giving  a  purple  precipitate  (instead 
of  scarlet)  with  oxymuriate  of  tin.  The  crimson,  purple,  and  mauve 
colors  it  yields  with  mordants  are  not  affected  by  acids  so  readily  as 
those  produced  directly  by  cochineal.  Ammoniaeal  cochineal  is  used  in 
admixture  with  ordinary  cochineal  for  producing  the  bluer  shades  of 
pink.  Cochineal-carmine  requires  for  its  production  a  decoction  of 
cochineal  itself  and  not  of  carminic  acid,  the  nitrogenized  matters  being 
essential  to  its  formation.  Liebermann,*  who  has  investigated  care- 
fully the  nature  of  the  cochineal  coloring  matter,  found  it  to  contain 
3.7  per  cent,  of  nitrogen,  of  which  only  .25  per  cent,  could  be  expelled 
by  boiling  with  dilute  alkali,  the  remainder  existing  apparently  as  pro- 
teids.  He  gives  the  following  as  the  composition  of  the  commercial  sam- 
ple of  carmine ,  examined  by  him:  Water,  seventeen  per  cent.;  nitrog- 
enous matter,  twenty  per  cent. ;  ash,  seven  per  cent. ;  coloring  matter, 
fifty-six  per  cent.;  wax,  traces.  Liebermann  considers  cochineal-car- 
mine to  be  no  ordinary  compound  of  a  coloring  matter  with  alumina, 
but  as  an  alumina-albuminate  of  the  carmine  coloring  matter,  compar- 
able in  some  respects  to  the  product  from  alizarin  and  alumina  with 
"  Turkey-red  oil."  Carmine  forms  red,  porous,  relatively  light  masses, 
which  are  easily  rubbed  up  to  a  fine  red  powder.  It  is  insoluble  in  water 
and  alcohol,  but  readily  soluble,  when  pure,  in  aqueous  ammonia. 
Cochineal-carmine  is  liable  to  adulteration  with  starch,  kaolin,  vermilion, 
red-lead,  chrome-red,  etc.  These  admixtures  may  be  detected  by  treat- 
ing the  sample  with  dilute  ammonia,  in  which  a  pure  sample  should  be 
completely  and  readily  soluble. 

M.  Dechan  f  has  published  a  series  of  analyses  of  commercial  car- 
mine, which  are  here  given : 

*  Ber.  Chem.  Gea.,  xviii,  p.  1971.  t  Pharm.  Journ.  [3],  xvi,  p.  511. 


508 


NATURAL  DYE-COLOES. 


1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

9. 

10. 

Moisture    

22.1 

16.1 

2.0 

22.3 

20.2 

23.5 

8.5 

10.0 

21.2 

13.0 

Soluble  in  f  Coloring  matter    . 
ether.     \  Alumina,  lime,  etc. 
T      i  T.I    (  Organic  matter  . 

46.1 
8.0 
21.8 

69.2 
9.8 
2.5 

34.1 
11.4 
18.5 

65.7 
12.0 

608 
9.0 
9.8 

69.5 
7.0 

26.1 
0.4 

72.0 

8.1 
8.0 

18.4 
4.4 
52.4 

67.5 
10.0 
9.5 

Insoluble)  YgE 

2.0 

2.4 

34.0 

Trace. 

0.2 

Trace. 

14.6 

1.9 

3.6 

Trace. 

in  ether.  \Vennilion.  '.'.'.'. 

50.4 

Cochineal  is  not  used  in  cotton-dyeing.  In  dyeing  silk  it  has  also 
been  almost  entirely  superseded  by  aniline  reds,  and  in  wool-dyeing  the 
azo  colors  have  to  a  great  extent  replaced  it.  Two  distinct  shades  of 
red  are  obtained  with  cochineal,  according  to  the  mordant  used, — 
cochineal-crimson  with  cream  of  tartar  and  alum,  and  cochineal-scarlet 
with  stannous  chloride  and  cream  of  tartar  or  oxalic  acid. 

2.  FROM  YELLOW  DYESTUFFS. — (a)   Old  Fustic   Extracts. — Both   a 
liquid  extract  of  about  20°  B.  and  a  solid  extract  have  been  prepared. 
The  latter  forms  large  yellowish-brown  blocks  of  a  waxy  lustre,  which 
dissolve  in  water  with  yellow  color.     They  are  prepared  from  the  wood 
by  diffusion.     The  name  morin  has  been  given  to  a  commercial  product 
obtained  by  boiling  the  rasped  wood  with  a  two  per  cent,  soda  solution 
and  evaporating  the  solution  so  obtained  to  a  specific  gravity  of  1.041, 
when  on  cooling  the  morin  and  moritannic  acid  separate  out. 

(&)  Quercitron  Extracts,  etc. — Both  liquid  and  solid  extracts  are 
used  commercially.  The  former  of  20°  and  30°  B.  respectively,  and 
the  latter  as  a  dark-brown  mass  of  waxy  lustre.  The  extracts  contain,  as 
a  rule,  mixtures  of  quercitrin  and  quercetin.  Flavine  has  already  been 
referred  to.  It  is  a  preparation  in  which  the  quercitrin  of  the  bark  has 
been  extracted,  and  in  large  part  changed  by  subsequent  treatment  with 
sulphuric  acid  into  quercetin,  which  is  superior  in  coloring  power.  The 
tannic  acid  of  the  bark  extract  has  also  been  removed  and  the  lime  salts, 
so  that  it  gives  much  purer  colors  than  the  original  extract.  Flavine 
is  largely  used  in  connection  with  cochineal  or  lac-dye  for  producing 
scarlet.  A  quercitron  extract  to  which  stannite  of  soda  or  sulphate  of 
zinc  has  been  added  is  said  to  be  used  under  the  name  of  "  Fustic  Sub- 
stitute." It  can  be  told  from  genuine  extract  of  fustic  by  the  test  with 
ferric  chloride,  which  produces  a  brown  precipitate,  turning  olive-green 
with  fustic,  but  a  greenish-black  with  quercitron  extract. 

(c)  Persian  Berries. — A  thick  extract  is  prepared  from  Persian  ber- 
ries, soluble  in  water  with  yellow  color  shading  into  brown.  The  solu- 
tion becomes  clearer  on  addition  of  hydrochloric  or  nitric  acids  and 
deposits  a  dirty-yellow  precipitate.  Ammonia  or  caustic  soda  colors  it  a 
reddish-yellow,  stannous  chloride  gives  at  once,  and  stannic  chloride 
after  the  addition  of  carbonate  of  soda,  a  golden-yellow  precipitate,  iron 
salts  a  dark  olive-green  to  greenish-black  color.. 

3.  FROM  BLUE  DYESTUFFS. —  (a)  Commercial  Indigo  occurs  in  lumps 
or  fragments  of  a  deep-blue  color,  usually  showing  a  bronze  or  purple- 
red  streak  when  rubbed  with  any  hard  substance,  or  in  the  case  of  the 
better  kinds  with  the  friction  of  the  thumb  only.     The  fracture  of  indigo 
is  dull  and  earthy,  it  sticks  to  the  tongue,  is  odorless  and  tasteless.     The 


PRODUCTS. 


509 


specific  gravity  varies  from  1.324  to  1.455.  Helen  Cooley*  has  given 
the  following  determinations  of  indigotin,  ash,  and  specific  gravity  in 
a  number  of  samples  of  commercial  indigo : 


DESCRIPTION. 

Specific  gravity. 

Ash. 

Indigotin. 

Kurpah  blue    

1.129 

17.54 

55.11 

Watson's  best  

1.292 

6.50 

59.53 

Bengal  red        

1.391 

6.41 

54.03 

Oude                 

1  427 

7.02 

52.90 

Bengal  blue  

1.431 

7.50 

67.60 

Kurpah  red  

1.529 

21.20 

45.28 

Guatemala    

1.559 

14.49 

47.04 

Indigo  preparations  have  been  referred  to  under  processes  (see  p. 
504),  and  it  was  then  noted  that  the  salts  of  the  indigo-sulphonic  acids 
constituted  the  several  so-called  indigo  extracts.  Indigo-carmine  is  the 
potassium  or  sodium  sulphindigotate  (C16H8(SO3K)2N2O2).  It  comes 
into  commerce  in  both  paste  and  solid  form.  It  is  soluble  in  one  hun- 
dred and  forty  parts  of  cold  water,  readily  soluble  in  dilute  sulphuric 
acid.  It  dyes  animal  fibres  direct,  but  with  a  much  lighter  shade  than 
indigo,  and  is  not  at  all  so  fast  to  light,  while  to  vegetable  fibres  it  shows 
no  affinity.  An  analysis  of  the  several  grades  of  carmine-paste  by 
Mierzinski  f  gave : 


DESCRIPTION. 

Water. 

Indigo. 

Salt. 

Carmine  I  

89.0 

4.96 

5.7 

85.0 

10.02 

4.8 

Carmine  III  

73.7 

12.04 

13.9 

Saxony  Blue  (Chemic  Blue}  is  the  free  sulphindigotic  acid,  C16H8 
N,(X(S03H)2,  and  forms  a  deep-blue  solution.  It  is  prepared  as  in  the 
making  of  indigo-carmine,  except  the  acid  is  not  saturated  with  alkali. 
It  was  largely  used  in  dyeing  wool,  but  is  not  adapted  for  silk.  Indigo- 
purple  is  a  reddish-violet  powder,  which  mixed  with  varying  amounts 
of  orseille  can  be  used  for  dyeing  wool  directly  without  mordants.  For 
its  preparation,  powdered  indigo  is  covered  with  ordinary  (not  fuming) 
sulphuric  acid,  and  having  been  cooled  is  left  for  half  an  hour.  In  this 
way  is  obtained  a  blue  solution  of  sulphindigotic  (indigo-disulphonic) 
acid,  which  can  be  worked  up  into  indigo-carmine  and  a  violet  powder. 
This  latter  is  the  monosulphonic  acid,  which  is  washed  first  with  water 
and  then  with  dilute  soda  solution  until  the  washings  are  no  longer  acid, 
then  dried  for  use  as  above.  A  product  of  analogous  composition,  known 
as  Boiley's  Blue,  is  prepared  by  gradually  adding  one  part  of  finely- 
powdered  indigo  to  ten  or  twenty  parts  of  acid  sodium  sulphate,  HNa 
S04,  in  a  state  of  fusion.  The  product  is  dissolved  in  water,  precipi- 
tated with  common  salt,  and  washed  with  brine.  Boiley's  blue  is  a 
crystalline  light-purplish  mass,  soluble  in  water  with  beautiful  blue- 
violet  color.  Its  solution  in  strong  boiling  acetic  acid  deposits  on  cool- 


*  Amer.  Journ.  Anal.  Chem.,  ii,  p.  130.  f  Ganswindt,  FJirberei,  p.  150. 


510 


NATURAL  DYE-COLORS. 


ing  large  prismatic  crystals  exhibiting  a  coppery  reflection.  It  is  in- 
soluble in  alcohol  or  ether,  but  readily  soluble  in  hot  water.  The  light 
transmitted  by  the  solution  is  red.  With  barium  and  strontium  salts  it 
yields  violet  precipitates. 

The  fact  that  indigo  had  been  obtained  artificially  by  several  differ- 
ent methods  was  mentioned  under  the  artificial  dye-colors.  (See  p. 
465.)  A  synthesis  of  indigo-carmine  has  also  been  effected  within  re- 
cent years.  The  process,  due  to  B.  Heymann,*  is  as  follows:  One  part 
of  phenyl-glycocoll  (C6H5.NHCH2.COOH)  is  rubbed  up  with  ten  to 
twenty  times  its  volume  of  clean  sand  (which  simply  acts  in  the  way  of 
reducing  the  temperature  of  the  reaction),  and  slowly  added  to  fuming 
sulphuric  acid,  with  eighty  per  cent,  anhydride  strength,  warmed  to 
20°  to  25°  C.  Care  is  to  be  taken  that  the  temperature  does  not  thereby 
exceed  30°  C.  After  the  solution  of  the  phenyl-glycocoll,  which  takes 
place  with  evolution  of  sulphurous  oxide,  concentrated  sulphuric  acid 
of  66°  B.  is  added  to  remove  the  excess  of  anhydride.  It  is  then  diluted 
with  ice  and  common  salt  added,  when  indigo-carmine  (indigo-disul- 
phonic  acid)  at  once  separates  out.  Experiments  on  dyeing  with  the 
new  product  show  it  to  be  better  and  purer  than  the  commercial  indigo- 
carmine.  Its  identity  was  established  in  a  number  of  ways.  The  yield 
amounts  to  sixty  per  cent,  of  the  theoretical,  but  this  may  be  improved 
by  further  study  of  the  conditions  of  the  reaction. 

(6)  From,  Logwood. — Logwood  Extracts  are  prepared  as  liquids 
of  12°,  42°,  and  51°  Tw.  (for  equivalents  of  the  Beaume  scale,  see  Ap- 
pendix) and  as  a  solid.  This  latter  forms  a  dry  black,  lustrous  and 
resin-like  mass,  which  is  quite  brittle  and  easily  powdered,  taste  sweet- 
ish astringent,  and  yields  a  reddish-brown  solution.  The  specific  gravity 
ranges  from  1.45  to  1.51.  The  specific  gravity  is  not  a  reliable  indica- 
tion of  the  strength  of  the  fluid  extract,  as  it  is  liable  to  be  raised  by  the 
addition  of  salt,  glucose,  molasses,  etc.  The  extracts  are  also  sometimes 
adulterated  with  starch,  dextrin,  chestnut-bark  extract,  hemlock  extract, 
etc.  The  following  table  by  Bruhl  f  gives  the  yields  of  extracts  ob- 


DESCRIPTION  OF  WOOD. 

Yield  of 
extract 

Soluble  in 
ether. 

Soluble  in 
absolute 
alcohol. 

Residue. 

Yucatan     

2020 

60  12 

37  46 

2  42 

Yucatan,  E.  J  

17.34 

58.34 

38  51 

3  15 

Laguna  

21.00 

51  37 

47  95 

0  68 

St.  Domingo  

1402 

44  95 

•53  47 

1  58 

19.30 

43  81 

50  32 

5  87 

Monte  Christo,  1884    

18.75 

3200 

60  32 

7  68 

Monte  Christo,  1887     

14  00 

34  72 

54  10 

11  18 

Fort  Liberte,  1886    

20  33 

41  89 

54  11 

4  00 

Fort  Liberte,  1887    

1600 

50  00 

47  92 

2  08 

Fort  Liberte,  1885-86  

17  45 

59  7.2 

35  17 

5  21 

Fort  Liberte,  J.  B.,  1887    

18.00 

59  24 

34  81 

5  95 

18  70 

43  20 

60  50 

6  30 

Jamaica  

18.00 

43  05 

50  71 

6  24 

Jamaica  wood  roots  

1070 

52  99 

30  12 

16  89 

*  Ber.  Chem.  Ges.,  xxiv,  p.  1476. 
t  Textile   Colorist,  x,  p.   148. 


ANALYTICAL  TESTS  AND  METHODS.  511 

tained  by  himself  from  different  woods  and  the  percentage  solubility  of 
the  resulting  extracts  in  ether  and  alcohol.  The  portion  dissolved  by 
ether  represents  roughly  the  hasmatoxylin  percentage,  while  that  dis- 
solved by  absolute  alcohol  represents  the  haematein  and  decomposition 
products  of  the  hcematoxylin. 

Indigo  Substitute  (Noir  imperial,  or  Kaiser schwarz] . — Under  these 
names  are  known  oxidized  logwood  extracts,  made  by  boiling  logwood 
extract  with  copper,  iron,  or  chromium  salts  with  the  addition  of  oxalic 
acid.  They  may  be  in  liquid  form,  or  pastes,  or  dry  powders.  The 
preparations  are  almost  insoluble  in  water,  but  completely  soluble  in 
acids  with  yellowishrbrown  color.  A  commercial  preparation  of  this 
class,  known  as  "  direct  black,"  for  cotton  forms  a  brownish,  viscid 
liquid,  composed  of  fifty  per  cent,  water,  forty-five  per  cent,  of  a  sub- 
stance soluble  in  alcohol  and  ether  (hgematoxylin  and  haematein),  and 
3.5  per  cent,  of  copper  sulphate.  Hcematein  (Hematin)  is  a  commer- 
cial preparation  of  French  origin,  which  claims  to  consist  of  nearly  pure 
dyestuff.  It  forms  a  granular,  reddish-brown  powder,  completely  soluble 
in  water,  and  dyes  the  same  shades  as  those  obtained  from  the  wood. 
Fifteen  kilos,  of  hsematein  are  said  to  be  equivalent  to  one  hundred 
kilos,  of  the  logwood.  Hematine  crystals  is  a  solid  logwood  extract  made 
porous  by  the  addition  of  nitrite  of  sodium  just  before  solidifying. 

(c)  Litmus,  as  has  been  said,  is  a  mixture  of  the  lichen  dye  of  that 
name  with  chalk  or  gypsum  as  inert  material.  It  is  made  in  different 
numbered  grades,  containing  different  amounts  of  the  mineral  matter. 
Litmus  in  the  dry  form  has  a  violet-blue  color,  is  quite  friable,  and  dis- 
solves in  water  and  dilute  alcohol,  leaving  a  residue  of  chalk,  gypsum, 
alumina,  silica,  etc. 

4.  FROM  BROWN  DYES. —  (a)  Catechu  has  been  described  already  in 
part  under  the  raw  materials  of  the  tanning  industry.  (See  p.  359.) 
It  is  not  unfrequently  adulterated  with  starch,  sand,  clay,  and  blood. 
Good  catechu  should  yield  at  least  half  its  weight  to  ether  and  should  be 
entirely  soluble  in  boiling  water,  the  latter  solution  depositing  catechu 
on  cooling.  Catechu  does  not  wholly  dissolve  in  cold  water  unless  it 
has  been  previously  modified  by  age  or  exposure  to  damp.  It  should 
not  yield  more  than  five  per  cent,  of  ash.  Prepared  Catechu  has  been 
merely  purified  by  mechanical  means.  For  this  purpose,  the  commer- 
cial catechu  is  fused  on  the  water-bath,  whereby  sand,  earth,  and  simi- 
lar impurities  settle  out,  and  then  it  is  strained  to  remove  leaves,  etc. 
The  material  so  obtained  is  again  melted  on  the  water-bath,  and  to 
every  one  hundred  parts  of  the  catechu  three-fourths  per  cent,  of  potas- 
sium bichromate  is  added,  when  it  is  allowed  to  cool  down  again. 

IV.  Analytical  Tests  and  Methods. 

1.  FOR  DYE-WOODS. — Here  the  question  of  adulteration  does  not  come 
notably  in  play.  The  compact  woods  are  not  capable  of  much  adultera- 
tion of  any  kind.  When  chipped  or  rasped;  however,  they  may  be  adul- 
terated quite  considerably.  The  examination  with  the  microscope  or 
simple  lens  will  often  suffice  to  indicate  the  nature  of  this  adulteration. 


512  NATURAL  DYE-COLORS. 

A  special  case  of  cheapening  is  that  of  the  cured  or  fermented  logwood 
chips,  which,  as  has  already  been  stated,  may  take  up  as  the  result  of 
this  fermentative  process  as  much  as  thirty  to  forty  per  cent,  of  water. 
In  this  case  a  moisture  determination  will  show  the  change,  allowance 
being  made  for  the  fourteen  per  cent.,  which  is  the  average  moisture  of 
the  unfermented  wood. 

To  determine  the  comparative  dyeing  value  of  different  samples  of 
woods,  the  only  thoroughly  reliable  test  is  an  actual  dyeing  test  made 
with  definite  weights  of  the  wood,  thoroughly  extracted,  and  using 
definite  amounts  of  mordants  upon  the  wool  or  other  fibre  used.  This 
test,  as  applied  to  logwood,  for  example,  would  be  carried  out  as  fol- 
lows :  Ten  gramme  portions  of  clean  wool  are  separately  mordanted  for 
li/2  hours  at  the  boil  with  3  per  cent,  of  potassium  bichromate  and  2y2 
per  cent,  of  cream  of  tartar,  washed,  and  dyed  for  1  hour  at  the  boil  in 
the  logwood  bath,  containing  a  definite  amount  of  decoction  or  extract 
of  each  sample  to  be  tested,  afterwards  washing  and  dyeing  for  the  final 
comparison  of  shade.  This  method  of  logwood  assay  takes  cognizance 
both  of  the  actual  and  the  potential  coloring  matter  present  (hasmatein 
and  haematoxylin),  and  is  a  more  rational  method  of  examination  than 
any  based  on  the  color  produced  on  cotton  mordanted  with  alumina  or 
tin  salts.  The  dye  test  in  other  cases  must  be  made  upon  a  normal  pre- 
pared extract  of  known  strength  and  purity,  and  the  result  compared 
with  those  obtained  with  a  corresponding  weight  of  the  supposed  adul- 
terated sample. 

2.  FOR  DYE-WOOD  AND  OTHER  EXTRACTS. — (a)  Orseille  Extract. — 
This  may  be  adulterated  with  logwood  or  Brazil-wood  extract.  They 
may  be  detected,  according  to  Leeshing,  as  follows :  A  solution  of  orseille 
extract,  much  diluted  and  acidified  with  acetic  acid,  will,  if  pure,  when 
boiled  with  a  freshly  prepared  solution  of  stannous  chloride,  become 
pale  yellow  or  almost  colorless,  while  logwood  extract  solution  under 
similar  circumstances  will  show  a  violet  color  and  Brazil-wood  solution 
a  red  color.  If,  therefore,  the  orseille  is  adulterated  with  logwood  ex- 
tract a  permanent  grayish-blue  color  will  show,  if  with  Brazil-wood 
extract,  a  reddish  color. 

Orseille  is  also  found  frequently  to  have  been  adulterated  with 
aniline  dyes,  especially  magenta,  acid  magenta,  and  methyl  violet.  For 
the  detection  of  magenta  and  methyl  violet  Knecht*  employs  cotton 
yarn  dyed  with  chrysamin  (p.  464).  This  does  not  take  up  the  color- 
ing matter  of  the  orseille,  but  is  dyed  red  by  magenta  and  brownish-red 
by  methyl  violet.  To  detect  the  acid  magenta,  Kertesz  f  treats  the 
orseille  preparation  with  benzaldehyde  and  adds  to  the  solution  tin  salt 
and  hydrochloric  acid,  shaking  up  the  mixture  thoroughly.  If  acid 
magenta  was  present  a  red  color  will  remain,  while  with  pure  orseille 
the  solution  remains  colorless.  One  part  of  acid  magenta  in  one 
thousand  parts  of  orseille  it  is  said  can  be  thus  detected.  For  other 
tests  for  the  artificial  dye-colors  when  present  as  adulterants  in  orseille, 

*  Journ.  fiir  Prakt.  Chem.,  71,  p.  19.       f  Berichte  der  Chem.  Ges.,  xviii,  p.  1970. 


ANALYTICAL  TESTS  AND  METHODS. 


513 


see  Allen,  "Commercial  Organic  Analysis,"  2d  ed.,  iii,  pp.  322  and 
323. 

(&)  Quercitron  Extracts. — The  dyeing  value  of  the  extract,  as  well 
as  a  possible  adulteration  of  the  same  with  dextrine,  glue,  etc.,  can  be 
best  determined  by  an  actual  dye  test.  For  this  purpose,  wool  is  boiled 
with  1.5  per  cent,  of  tin  salt  and  three  per  cent,  of  oxalic  acid,  then 
washed.  One  gramme  of  the  wool  is  now  dyed  with  twenty  cubic  centi- 
metres of  a  solution  of  ten  grammes  of  the  quercitron  extract  in  one 
thousand  cubic  centimetres  of  water.  Similarly  several  portions  of  one 
gramme  each  of  mordanted  wool  are  dyed  with  solutions  of  pure  bark 
or  pure  extract  of  definite  strength,  and  the  results  compared. 

(c)  Annatto  (Orlean). — Annatto  possesses  only  a  slight  importance 
as  a  dyeing  agent,  but  special  importance  as  the  basis  of  most  butter 
colorings.  (See  p.  299.)  It  is,  therefore,  a  commercial  article  of  com- 
mon use  and  liable  to  be  adulterated.  The  common  adulterants  are 
starch,  dextrine,  chalk,  silica,  alumina  compounds  and  common  salt, 
together  with  ochre,  brick-dust.  Most  of  these  increase  notably  the 
percentage  of  ash,  which  in  a  pure  sample  it  is  said  should  not  exceed 
ten  to  twelve  per  cent.  Wynter  Blyth  gives  the  following  two  analyses 
as  illustrating  the  nature  of  its  adulteration: 


DESCRIPTION. 

Water. 

Resin. 

Extractive 
matter. 

Ash. 

Fair  commercial  sample    .    . 
Adulterated  sample    .... 

242 
134 

28.8 
11.0 

245 
27.3 

22.5 
40  o  f  Oxide  of  iron,  alumina, 
'    1    silica,  chalk,  and  salt. 

For  dyeing  purposes  the  only  satisfactory  test  is  an  actual  dyeing 
test  in  comparison  with  an  authentic  unadulterated  sample.  For  the 
analysis  of  the  many  butter-coloring  mixtures  containing  annatto  as 
the  basis  the  reader  is  referred  to  Allen,  "  Commercial  Organic 
Analysis,"  2d  ed.,  iii,  pp.  353-356,  and  Wynter  Blyth,  "Foods,  Com- 
position and  Analysis,"  p.  306. 

(d)  Logwood  Extract. — Both  the  liquid  and  the  solid  extracts  are 
liable  to  be  adulterated,  the  former  with  glucose,  molasses,  dextrine, 
salt,  and  other  extracts  of  lesser  value,  the  latter  with  starch  and  in- 
ferior extracts.  Notably  are  the  French  and  German  logwood  extracts 
adulterated  in  the  way  just  referred  to.  The  following  analyses  of  some 
of  the  commercial  extracts  as  currently  sold  in  France  and  Germany  are 
given  by  V.  H.  Soxhlet :  * 


DESCRIPTION  OF  EXTRACT. 

Molasses. 

Dextrine 

Chestnut  extract. 

Salt. 

Guaranteed  Pure,  30°  B.  .    . 
Prima,  30°  B  

5  per  cent. 
10 

Secunda,  30°  B  

20 

10  per  cent. 

10  per  cent. 

Secunda,  Solid    

20 

15   "       " 

Saaford  Brand,  I  

25 

15  per  cent. 

Sanford  Brand,  II  
Sanford  Brand,  III  

35 
35 

10   "       " 
15   "       " 

10   "       " 
15   "       " 

Farber-Zeitung,  Aug.  1,  1890,  p.  368. 
33 


514  NATURAL  DYE-COLORS. 

The  Sanford  Brand  here  referred  to  is  a  French  extract  made  in 
imitation  of  the  original  American  Sanford  Extract. 

The  extracts  may  be  tested  for  purity  either  by  the  colorimetric 
assay  or  by  comparative  dye  tests.  The  colorimetric  test  is  carried  out, 
according  to  Henry  Trimble,*  as  follows:  A  volume  of  solution  corre- 
sponding to  .001  gramme  of  the  dry  extract  is  treated  with  ten  cubic 
centimetres  of  water  naturally  or  artificially  containing  traces  of  cal- 
cium carbonate  and  a  solution  of  .002  gramme  of  crystallized  copper  sul- 
phate. The  mixture  is  brought  quickly  to  the  boiling-point  and  diluted 
with  distilled  water  to  one  hundred  cubic  centimetres.  The  color  of 
this  solution  is  then  compared  with  one  of  pure  hcematoxylin  similarly 
used,  or  with  a  standard  sample  of  logwood  extract. 

The  method  of  carrying  out  the  dye  test  for  logwood  with  bichro- 
mate of  potassium  mordant  has  already  been  given  in  speaking  of  dye- 
woods.  The  same  test  is,  of  course,  equally  applicable  to  the  extracts. 
Cotton  strips  are  sometimes  used  for  these  dye  tests  instead  of  wool. 
The  cotton  strips  must  be  boiled  in  dilute  soda  solution  and  well  washed. 
They  may  then  be  mordanted  with  nitrate  of  iron  solution  instead  of 
the  chromium  salt,  following  the  nitrate  of  iron  with  a  rinsing  in  car- 
bonate of  soda  solution  and  thorough  washing.  They  are  then  put  in 
the  dye-bath  cold,  and  this  gradually  heated  to  boiling.  In  this  dye- 
testing  with  iron  solution,  the  hsematoxylin  of  the  solution  is  oxidized 
by  the  ferric  oxide  to  hgematein,  so  that  the  full  coloring  value  of  the 
logwood  is  obtained  in  the  test. 

For  the  discovery  of  adulterations  like  chestnut  extract,  which  con- 
tain almost  nothing  soluble  in  ether,  Houzeau  proceeds  as  follows:  One 
gramme  of  the  extract  to  be  investigated  is  dried  at  110°  C.,  exhausted 
with  ether,  and  the  weight  of  the  dissolved  material  determined.  The 
undissolved  material  is  then  exhausted  with  absolute  alcohol,  and  the 
weight  of  the  portion  dissolved  by  this  also  determined.  The  compari- 
son of  the  figures  so  obtained  with  those  yielded  when  a  pure  extract  is 
treated  with  the  same  solvents  will  show  clearly  the  presence  or  absence 
of  adulterating  extract.  Dye  tests  may  also  be  carried  out  with  the 
material  which  has  been  extracted  by  ether  and  alcohol  respectively  in 
the  two  cases,  and  the  difference  more  fully  established. 

(e]  Catechu  Extract. — Catechu  is  frequently  adulterated,  not  only 
with  mineral  matter  like  sand  and  clay,  but  with  starch,  dextrine,  sugar, 
blood,  etc.  The  mineral  matters  will,  of  course,  remain  in  the  ash.  This 
in  normal  catechu  should  not  exceed  five  per  cent.  The  starch  may  be 
detected  by  extracting  the  sample  with  alcohol,  boiling  the  insoluble 
residue  with  water,  and  testing  the  cooled  liquid  with  iodine,  which  will 
show  by  the  blue  color  any  starch  present.  An  addition  of  alcohol  to 
the  aqueous  solution  will  show  by  the  production  of  a  turbidity  any 
notable  quantity  of  dextrine.  Blood  may  be'  detected  by  treating  the 
sample  with  alcohol,  and  drying  and  heating  the  residue  in  a  tube,  when 
ammonia  and  offensive  decomposition  products  will  be  given  off,  or  the 
coagulation  of  the  blood  albumen  when  the  aqueous  solution  is  boiled. 

*  Journ.   Soc.  Dyers,  etc.,  i,  p.  92. 


ANALYTICAL  TESTS  AND  METHODS.  515 

The  value  of  catechu  for  dyeing  purposes  can  only  be  determined  by 
a  dye  test.  For  this  purpose  strips  of  cotton-stuff  are  immersed  for 
half  an  hour  in  a  catechu  solution  (for  each  gramme  of  the  cotton  fifty 
cubic  centimetres  of  a  catechu  solution  containing  five  grammes  to  the 
litre  of  water  are  taken  and  diluted  with  water  if  necessary).  The 
strips  are  pressed  out,  and  then  the  color  developed  by  oxidizing  in  a  hot 
solution  of  one  to  two  grammes  of  potassium  bichromate  to  the  litre  of 
water. 

3.  FOB  COCHINEAL. — The  adulteration  of  cochineal  may  be  effected 
in  various  ways.  A  very  common  adulteration  is  to  admix  with  the 
fresh  cochineal  insects  others  from  which  the  coloring  power  has  already 
been  in  large  part  extracted.  To  give  the  exhausted  cochineal  insects 
the  appearance  of  fresh  ones,  they  are  shaken  up  with  talc,  barytes,  and 
white  lead,  and  thus  given  a  coating  resembling  the  silvery  insects. 
Either  a  washing  or  an  ash  determination  will  serve  to  detect  this  adul- 
teration. The  valuation  of  the  cochineal  as  to  coloring  power  may  be 
made  by  several  methods.  The  one  best  known  is  that  of  Penny,*  in 
which  one  gramme  of  the  cochineal  is  treated  with  fifty  grammes  of 
dilute  potassium  hydroxide,  twenty-five  grammes  of  water  added,  and  to 
this  is  then  added  drop  by  drop  a  solution  of  ferricyanide  of  potassium 
containing  five  grammes  to  the  litre.  The  solution  loses  its  purplish- 
red  color  and  becomes  brownish-yellow.  The  action  of  the  ferricyanide 
of  potassium  solution  is  tested  in  comparison  on  the  solution  of  one 
gramme  of  a  cochineal  of  known  purity.  Liebermann  f  extracts  the 
cochineal  with  boiling  water,  and  determines  the  coloring  matter  by  the 
addition  of  a  slightly  acid  solution  of  lead  acetate.  After  filtering  and 
washing  the  lead  precipitate,  a  lead  determination  is  made  in  an  aliquot 
portion,  and  from  this  the  percentage  of  coloring  matter  calculated. 
Allen  does  not  consider  either  of  these  methods  to  be  perfectly  satisfac- 
tory. An  actual  dye  test  is  therefore  in  the  end  to  be  regarded  as  the 
most  reliable  method  of  valuation.  For  this  purpose  strips  of  woollen 
stuff  of  about  five  grammes  in  weight  are  put  into  the  bath  until  the 
color  is  all  taken  up.  A  portion  of  the  strips  may  then  be  dyed  scarlet- 
red  by  immersing  them  in  a  tin  solution  (for  one  gramme  of  cochineal 
two  grammes  of  cream  of  tartar,  two  grammes  of  tin  salt,  and  as  much 
water  as  is  needed  to  thoroughly  immerse  the  strips),  and  the  other 
portion  of  the  strips  may  be  dyed  a  cherry-red  by  the  use  of  an  alum 
solution  (for  one  gramme  of  cochineal,  three-fourths  gramme  of  cream 
of  tartar  and  one  and  a  half  grammes  of  alum).  These  strips  are  then 
to  be  compared  with  others  obtained  from  similar  treatment  of  a  nor- 
mal or  pure  cochineal  sample. 

4.  FOR  INDIGO  AND  ITS  PREPARATIONS. — Indigo  may  be  of  very 
varying  value  as  it  comes  into  commerce,  partly  because  of  the  differences 
natural  to  such  a  product  and  dependent  upon  the  differences  in  cultiva- 
tion of  the  plant,  care  in  extracting  and  drying  the  indigo,  and  the  fact 
that  the  natural  product  is  at  best  a  mixture,  and  partly  from  inten- 
tional adulteration.  Thus  starch  colored  with  iodine,  Prussian  blue, 

*  Journ.  fur  Prakt.  Chem.,  71,  p.  119.     f  Berichte  der  Chera.  Ges.,  xviii,  p.  1970. 


516  NATURAL  DYE-COLORS. 

smalt,  and  logwood-powder  are  said  to  be  used  as  adulterants  of  com- 
mercial indigo.  In  order  to  detect  the  starch,  the  suspected  sample  is 
rubbed  up  in  a  mortar  with  chlorine-water  until  it  is  completely  decolor- 
ized, when  a  drop  of  potassium  iodide  is  added.  If  starch  be  present 
the  blue  color  of  iodide  of  starch  will  be  seen.  To  detect  the  smalt  or 
Prussian  blue,  the  sample  is  oxidized  with  nitric  acid,  when  if  a  blue 
residue  is  shown  in  the  yellowish  solution  adulteration  is  indicated.  If 
the  adulterant  were  Prussian  blue,  the  color  fades  too  after  a  time,  if 
smalt,  it  is  permanent.  To  detect  logwood-powder,  mix  the  sample  with 
oxalic  acid,  place  it  upon  filter-paper,  and  moisten  it;  in  the  presence 
of  logwood  the  paper  will  be  colored  red,  if  the  sample  were  pure  it  is 
unchanged. 

In  the  assay  of  commercial  indigo  the  moisture  is  generally  to  be 
determined.  This  should  not  exceed  some  seven  per  cent,  in  a  genuine 
sample.  The  ash  similarly  is  an  important  criterion  of  the  quality  of 
the  indigo  sample.  In  the  purest  kinds  it  is  sometimes  as  low  as  two 
per  cent.,  but  from  five  to  eight  per  cent,  is  more  usual.  Some  of  the 
inferior  grades  of  indigo,  such  as  Kurpah  and  Madras,  may  contain  from 
twenty-five  to  thirty-five  per  cent,  of  ash. 

The  methods  for  the  determination  of  the  percentage  of  indigo-blue 
are,  of  course,  the  most  important  things  to  be  considered  in  connection 
with  indigo  as  a  dyeing  material.  They  are  very  numerous.  We  may 
summarize  the  more  important  of  them  under  .three  heads, — viz.,  oxida- 
tion methods,  reduction  methods,  and  sublimation  of  the  pure  indigo- 
blue  from  the  commercial  product. 

The  oxidation  of  the  indigo-blue  takes  place  in  acid  solution,  the 
indigo  being  previously  dissolved  in  strong  sulphuric  acid.  Potassium 
permanganate,  bichromate,  and  ferricyanide  have  all  been  recommended 
and  used  in  this  connection.  All  the  processes  are  open  to  the  objec- 
tion that  the  oxidizing  agents  act  on  the  indigo-gluten  and  ferrous  salts 
as  well  as  on  the  indigo-blue  and  indigo-red,  but  the  errors  due  to  this 
cause  may  be  practically  avoided,  as  pointed  out  by  Rawson,  by  pre- 
viously precipitating  the  sulphindigotic  acid  in  the  form  of  the  sodium 
salt  by  adding  common  salt  to  the  solution.  The  method  with  per- 
manganate of  potassium,  modified  in  this  manner  by  the  use  of  common 
salt,  is  as  follows :  *  One  gramme  of  the  sample  of  indigo  in  the  form 
of  an  impalpable  powder  is  mixed  in  a  small  mortar  with  its  own  weight 
of  ground  glass.  This  mixture  is  gradually  added  with  constant  stir- 
ring to  twenty  cubic  centimetres  of  concentrated  sulphuric  acid  (specific 
gravity  1.845),  which  is  then  heated  to  about  85°  C.  for  an  hour.  The 
product  is  then  cooled,  diluted  with  water  to  one  litre,  and  filtered  from 
indigo-brown  and  other  soluble  matter.  Fifty  cubic  centimetres  of  the 
filtered  solution  are  now  taken,  diluted  with  fifty  cubic  centimetres  of 
water,  and  thirty-two  grammes  of  common  salt  added,  which  quantity 
is  almost  sufficient  to  saturate  the  liquid.  After  standing  for  two  hours, 
the  solution  is  filtered,  and  the  precipitate  washed  with  about  fifty  cubic 
centimetres  of  brine  of  1.2  specific  gravity.  This  sodium  sulphindi- 

*  Allen,  Commercial  Organic  Analysis,  2d  ed.,  iii,  p.  308. 


ANALYTICAL  TESTS  AND  METHODS.  517 

gotate  is  dissolved  in  hot  water,  the  solution  cooled,  mixed  with  one  cubic 
centimetre  of  sulphuric  acid,  and  diluted  to  three  hundred  cubic  centi- 
metres. This  solution  is  then  titrated  in  a  porcelain  dish  with  a  solution 
of  potassium  permanganate  containing  .5  gramme  of  the  solid  salt  per 
litre,  the  exact  oxidizing  power  of  which  has  been  ascertained  by  experi- 
ment with  a  solution  of  pure  indigotin.  The  oxidation  is  regarded  as 
complete  when  the  liquid  which  at  first  takes  a  greenish  tinge  changes 
to  a  light  yellow  with  a  faint  pink  color  on  the  margin. 

The  reduction  of  indigo-blue  may  take  place  in  alkaline  solution  or 
with  a  solution  of  the  sulphindigotic  acid  or  its  salts.  Ferrous  hydrox- 
ide and  hyposulphites  are  among  the,  reducing  agents  used  to  effect  the 
reduction  in  alkaline  solutions.  C.  Rawson  considers  the  hyposulphite 
reduction  method  the  better  one  of  the  two.  In  carrying  it  out,  one 
gramme  of  the  finely-powdered  sample  is  made  into  a  paste  with  water 
and  placed  in  a  flask  with  about  six  hundred  cubic  centimetres  of  lime- 
water.  The  flask  is  closed  by  a  cork  having  four  perforations,  two  of 
which  serve  for  the  passage  of  coal-gas,  a  third  carries  a  siphon,  while 
to  the  fourth  is  fitted  a  tap-funnel.  The  contents  of  the  flask  are 
heated  to  80°  C.  and  one  hundred  to  one  hundred  and  fifty  cubic  centi- 
metres of  a  strong  solution  of  sodium  hyposulphite  (NaHS02)  intro- 
duced through  the  tap-funnel.  In  a  few  minutes  the  liquid  assumes  a 
yellow  tint,  and  is  maintained  at  a  temperature  near  the  boiling-point 
for  half  an  hour.  After  allowing  the  insoluble  matters  to  subside,  an 
aliquot  portion  of  the  solution  should  be  removed,  and  a  current  of  air 
drawn  through  it  for  about  twenty  minutes,  when  it  is  acidulated  with 
hydrochloric  acid.  The  precipitate,  which  consists  of  indigotin  and 
indigo-red,  is  collected  on  a  weighed  filter,  washed  with  hot  water,  dried 
at  100°  C.,  and  weighed.  It  is  then  exhausted  with  boiling  alcohol, 
whereby  the  indigo-red  is  dissolved  out  and  the  difference  again  weighed 
as  indigo-blue.  Rau  reduces  the  indigo  in  alkaline  solution  with  glu- 
cose, and  L.  M.  Norton  uses  milk  of  lime  and  zinc-dust  as  reducing 
agent,  and  then  takes  an  aliquot  portion  of  the  reduced  solution  to  re- 
duce a  solution  of  iron-alum.  The  ferrous  salt  formed  corresponds  to 
the  reduced  indigo  in  the  volume  taken,  and  is  determined  by  titration 
with  a  standard  solution  of  potassium  bichromate.  (For  details,  see 
Helen  Cooley's  article,  Amer.  Journ.  Anal.  Chem.,  ii,  p.  133.) 

For  the  reduction  of  the  indigo  in  acid  solution,  Bernthsen  and 
Drew*  recommend  the  use  of  hyposulphite  of  soda  (NaHS02),  and 
claim  that  the  reaction  is  a  quantitative  one:  C10H8N202(S03H)2  -f- 
NaHS02  +  H2O  =  C16H10N2O2(S03H)2  -f  NaHSO3. 

C.  Rawson  f  considers  that  of  all  the  volumetric  methods  which  have 
been  devised  for  estimating  indigotin  the  hyposulphite  process  is  capable 
of  giving  the  most  rapid  and  accurate  results,  but  that  considerable 
care  and  delicacy  are  required  in  its  manipulation. 

Lee  I  has  proposed  the  sublimation  of  the  indigo-blue  as  a  method 
for  determining  its  percentage  in  commercial  indigo.  Other  writers, 

*  Chem.  News,  xliii,  p.  80.  f  Allen's  Com.  Org.  Anal.,  2d  ed.,  iii,  p.  309. 

J  Chem.  News,  1,  p.  49. 


518 


NATURAL  DYE-COLORS. 


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BIBLIOGRAPHY  AND   STATISTICS. 


519 


however,  do  not  agree  that,  unless  the  indigo  has  previously  been  some- 
what purified,  the  results  can  be  depended  upon. 

C.  Rawson  *  has  given  the  following  results  with  commercial  sam- 
ples, using  the  several  processes  just  detailed: 


METHOD  USED. 

Java. 

Bengal. 

Bengal. 

Oude. 

Kurpah. 

Madras. 

2.99 

522 

6  17 

7  50 

8  05 

5  71 

Ash     

1.99 

3.91 

4  86 

8  21 

25  72 

33  62 

Indigotin,  by  sublimation  .... 
Indigvjtin,  volumetric,  by  hypo- 
sulphite   

GO.  84 
68  78 

57.50 
59  26 

49.36 
55  66 

41.60 
43  18 

41.92 
42  52 

39.66 
36  80 

Indigotin,  gravimetric,  by  ferrous 
sulphate  and  NaOH  

68.24 

58.84 

54  34 

44  50 

41  50 

34  50 

Indigotin,  gravimetric,  by  hypo- 
sulphite and  lime   

68.97  \ 

59  12  \ 

56  20  \ 

43  42  •> 

42  68  \ 

35211 

Indirubin,  separated  by  alcohol   . 
Indigotin  and  indirubin,  titration 
with  KMnO4  direct    

4.23  / 
76.18 

3.50  / 
66.71 

2.80  / 
6266 

3.65/ 
5004 

2.45  / 
47  15 

3.98/ 
39.50 

Indigotin  and  indirubin  titration 
after  precipitation  with  salt  .    . 

73.55 

63.50 

57.50 

44.90 

43.10 

37.40 

The  table  from  Dammer's  Chem.  Technologic,  Band  iv,  p.  591  (see 
opposite  page),  shows  the  characteristic  reactions  of  the  important  nat- 
ural dyestuffs. 

V.  Bibliography  and  Statistics. 

BIBLIOGRAPHY. 

1877. — Tropical  Agriculture,  P.  L.  Simmonds,  London  and  New  York. 

1880. — Lexikon  der  Farbwaaren,  F.  Springmiihl,  Berlin. 

1881. — Les  Matidres  premieres,  Georges  Pennetier,  Paris. 

1882. — Dictionnaire  des  Alterations,  etc.,  Ed.  Baudrimont,  6me  <ld.,  Paris. 

Manual  of  Colors  and  Dye-wares,  J.  W.  Slater,  London. 

1883 Matieres   colorantes  et  ses  Applications,   Girard  et  Pabst,   Paris. 

1885. — The  Dyeing  of  Textile  Fabrics,  J.  J.  Hummel,  London. 

Die  Gesammte  Indigo-kupen-blau  Farberei,  etc.,  E.  Rudolf. 
1886. — Organische  Farbstoffe,  R.  Nietzki,  Breslau. 
1887. — Die  Gerb-  und  Farbstoff  Extracte,  S.  Mierzinski,  Vienna. 

The  Printing  of  Cotton  Fabrics,  A.  Sansone,  Manchester. 

Lexikon  der  Verfiilschungen,  O.  Dammer,  Leipzig. 

The  Culture  and  Manufacture  of  Indigo,  W.  M.  Reid,  Calcutta. 
1889. — Das  Farben  und  Bleichen,  etc.,  Bd.  I.  Farbstoffe,  Dr.  J.  Herzfeld,  Berlin. 

Hand-book   of   Commercial   Geography,    Geo.   G.    Chisholm,   London. 

Handbuch   der  Farberei,  A.   Ganswindt,   Weimar. 
1890. — Les  Mati&res  colorantes,  etc.,  C.  J.  Tassart,  Paris. 

1892. — Der    Indigo   vom    praktischen    und    theoretischen    Standpunkte,    Georgievics, 
Wien. 

On  Indigo  Manufacture,  J.  B.  Lee,  London. 

1895. — Grundriss    der    Allgemeinen    Warenkunde,    Erdman-Konig,    12te    Auf.,    von 
Hanausek,  Leipzig. 

1899 Rohstoffe  des  Pflanzenreiches,  J.  Wiesner,  2te  Auf.,  Leipzig. 

1900. — Die  Chemie  Natiirlichen   Farbstoffe,   H.   Rupe,   Braunschweig. 


*  Allen,  Commercial  Organic  Analysis,  2d  ed.,  iii,  p.  311. 


520 


NATURAL  DYE-COLORS. 


1901. — A  Dictionary  of  Dyes,  Mordants  and  Other  Compounds,  Rawson,  Gardner  & 

Laycock,  London. 

1902. — L'Industrie  des  Mati&res  colorantes,  Dupont,  Paris. 
1908. — Indigo:   Report  to  the  Government  of  India  on  Research  Work  on,  during 

1905-1907,  Bloxam. 
1909. — Die  Chemie  der  Natiirlichen  Farbstoffe,  H.  Rupe,  2te  Theil,  Braunschweig. 

STATISTICS. 

1.  INDIGO,  NATURAL  AND  ARTIFICIAL. — The    exportations   of    natural 
indigo  from  British  India  have  decreased  greatly  owing  to  the  intro- 
duction of  synthetic  indigo.     The  exports  from  British  India  were: 

1896    169,500  cwt.  Value  43,700,000  rupees. 

1901-02    89,750     "  "       18,522,554 

1903-04    60,410     "  "       10,762,026       " 

1904-05    49,256     "  "         8,346,073       " 

1905-06 31,186     "  "         5,863,777       " 

1906-07 35,102     "  "         7,004,773       " 

The  area  under  cultivation  for  the  indigo  plant  in  British  India 
(Bengal,  Madras,  Agra,  Oude,  Punjab)  was  in: 

1896    1,600,000  acres 

1906    450,000  acres 

The  production    of    synthetic    indigo  has  grown  during  the  same 
period  as  follows: 

1900 1873  tons  1904 8730  tons 

1901 2673  tons  1905 11165  tons 

1902 5284  tons  1906 12733  tons 

1903 7233  tons 

2.  EXPORTATIONS    OF    DYE-WOODS. — The  exportations  of  several  of 
the  more  important  dye-woods  from  tropical  American  countries  for  the 
period  given  have  been  as  follows: 


1.  Logwood  Exports: 


From  Haiti. 


Pounds.  Value. 

1882-83  152,288,713  $1,998,789 

1883-84  154,775,837  2,031,434 

1884-85  142,986,254  1,876,695 

1885-86  114,341,436  1,500,731 

1886-87  105,000,065  1,378,125 

1887-88  106,163,734  1,393,399 

1888-89  57,021,431  748,406 

1889-90 70,801,241  929,266 

1890-91  56,743,891  744,764 

1891-92  39,766,320  521,933 

1892-93 


From  Jamaica. 


Pounds. 
66,685.584 
100,638,496 
126,795,200 
142,256,128 
13^,009,472 
226,108,912 
258,616,960 
133,232,400 
244,794,592 
194,152,784 
207,472,832 


Value. 

$434,632 

655,921 

743,774 

927,165 

932,089 

1,718,627 

1,826,035 

962,432 

1,861,395 

1,476,320 

1,633,947 


BIBLIOGRAPHY  AND    STATISTICS. 


521 


2.  Fustic  Exports: 


From  Mexico. 


•  • 

Pounds. 

Value. 

1882-83     

,  .      30,746,240 

$280,988 

1883-84     

.      32,995,200 

248,656 

1884-85     

.      17,471,509 

128,019 

1885-86     

.  .      17,420,099 

110,873 

1886-87     

.      24,942,407 

178,621 

1887-88     

.      26,583,858 

177,488 

1888-89     

.      18,224,030 

133,952 

1889-90     

.      23,762,671 

198,646 

1890-91     

.      16,927,020 

119,631 

1891-92     

.      13,187,368 

96,588 

1892-93     . 

From  Jamaica. 


Pounds. 

Value. 

7,477,792 

$48,738 

4,024,272 

21,857 

2,078,160 

13,093 

3,526,768 

21,071 

9,366,000 

61,044 

5,518,016 

35,964 

2,777,216 

10,425 

1,457,200 

8,606 

2,128,112 

12,714 

1,517,152 

9,888 

14,472,976 

102,190 

3.  Exports  of  Brazil-wood  from  Bahia  during  recent  years  were. 


To 

United  States. 
Kilos. 

1884  584,318 

1885  232,912 

1886  684,002 

1887  783,616 

1888  388,631 

1889  149,063 

1890  58,121 

1891  ..  251,873 

1892  635,030 

1893  615,158 


To 

England. 
Kilos. 
143,480 
292,212 

To 
Germany. 
Kilos. 

15,000 
49,568 

To 
France. 
Kilos. 

336,189 
703,497 

All  other 
countries. 
Kilos. 
56,350 

Total 
Kilos. 
1,135,337 

1,278,189 

193,189 
152,453 
84,341 

134,857 
46,640 
18,584 

904,348 
1,374,543 
369,725 

18,569 

1,934,965 
2,357,252 
861,280 

82,156 

753,457 

984,676 

166,198 

78,959 

127,016 
670,857 

21,321 

430,295 
944,051 

64,676 

25,782 

1,093,650 

1,819,138 

517,937 

147,177 

548,734 

8,970 

1,837,976 

3.  IMPORTATIONS  OF  DYE-WOODS  AND  DYE-WOOD  EXTRACTS  INTO  THE 
UNITED  STATES. 

1906. 
Annatto  extract  (Ibs.)  .  .  .       281,575 

Valued   at    $22,156 

Cochineal   (Ibs.)    111,007 

Valued   at $53,446 

Fustic   (tons)    5,783 

Valued  at    $89,513 

Gambier    ( Ibs. )     31,478,837 

Valued   at    $1,118,910 

Indigo,   crude    (Ibs.)     ...   7,196,678 

Valued   at    $1,046,023 

Indigo,  extract    (Ibs.)    ..       125,257 

Valued  at    $7,698 

Logwood    (tons)     36,624 

Valued  at $498,602 

Logwood    and    other    dye- 
wood   extracts    (Ibs.)    3,443,676 

Valued  at    $295,188 

Madder,  ground   (Ibs.)...        45,991 

Valued  at    $4,600 

Orchil,    value $33,980 

Saffron,  extract  of,  value     $59,964 

(Commerce  and  Navigation  of  U.  S,,  1910.) 


1907. 

1908. 

1909. 

1910. 

651,595 

551,872 

711,191 

619,372 

$51,128 

$40,708 

$48,839 

$39,579 

184,326 

152,624 

102,694 

150,811 

$84,911 

$54,146 

$33,875 

$41,445 

3,483 

4,452 

2,466 

5,816 

$54,765 

$53,884 

$34,752 

$82,887 

28,853,124 

26,692,100 

31,000,855 

25,808.720 

$977,000 

$895,210 

$1,313,990 

$1,264,023 

7,170,836 

6,078,073 

6,249,975 

7,636,690 

$1,233,515 

$1,058,354 

$1,400,000 

$1,195,942 

145,339 

140,291 

148,454 

142,831 

$8,013 

$14,391 

$17,897 

$16,435 

37,901 

21,809 

17,873 

31,270 

$478,656 

$248,578 

$166,371 

$353,311 

4,542,257 

3,576,676 

3,463,582 

2,937,628 

$368,704 

$230,475 

$231,612 

$187,124 

62,633 

50,856 

37,910 

30,700 

$5,721 

$5,249 

$3,019 

$2,312 

$31,880 

$29,924 

$45,818 

$38,769 

$74,468 

$70,569 

$67,648 

$80,700 

522  BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 


CHAPTER   XIV. 

BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 

PRELIMINARY. — Prior  to  the  operation  of  bleaching,  especially  in  cases 
where  delicate  shades  are  required,  it  is  always  necessary  to  thoroughly 
cleanse  the  fibre  or  fabric  of  grease  and  dirt.  For  cotton,  which  is  gen- 
erally handled  as  hanks,  warps,  and  pieces,  it  is  sufficient  to  boil  it  in 
a  dilute  solution  of  caustic  soda  or  soda  ash,  followed  by  a  good  rinsing ; 
it  may,  in  some  instances,  be  boiled  in  plain  water,  wrung  out,  and 
bleached  or  dyed;  ordinarily,  however,  a  boiling  for  two  or  three  hours 
in  a  bath  of  eight  to  ten  per  cent,  of  crystallized  soda  and  one  to  two 
per  cent,  of  soap,  calculated  to  the  weight  of  the  cotton,  yields  good 
result.  The  time  for  boiling  out  cotton  is  much  reduced  if  it  is  immersed 
in  a  weak  lukewarm  bath  of  two  per  cent,  sulphated  oil  strongly  neu- 
tralized with  ammonia  or  in  a  soap-bath  containing  ammonia.  This  is 
found  to  completely  remove  all  natural  oil  on  the  fibres  and  thoroughly 
wet  them.  Wool  is  always  thoroughly  scoured  both  before  and  after 
it  is  manufactured  into  yarn.  The  soap  solution  generally  employed  con- 
tains from  four  to  five  ounces  to  the  gallon  of  water,  accompanied  usually 
with  a  carbonated  alkali  (potash  or  ammonia)  in  about  the  following 
proportion:  ten  per  cent,  of  soda  and  two  per  cent,  of  soap.  The  tem- 
perature of  the  bath  is  about  40°  to  50°  C.  (See  p.  343.)  For  silk 
(see  p.  349)  the  boiling  off  contains  about  twenty-five  to  thirty  pounds 
of  Castile,  Marseilles,  or  other  neutral  soap  for  each  hundred  pounds 
of  silk,  and  a  temperature  at  or  near  the  boiling-point  is  taken  for  about 
two  hours,  turning  the  silk  occasionally.  For  some  colors  a  second 
boiling  off  can  be  employed  to  advantage,  only  one-half  the  quantity  of 
soap  being  used  as  in  the  first  bath.  It  is  the  practice  to  use  the  baths 
several  times,  care  being  taken  to  enrich  them  with  fresh  soap. 

A.  BLEACHING. — This  highly-important  operation  results  in  a  more 
or  less  complete  destruction  of  the  natural  coloring  matter  which  is  found 
in  all  fibres  of  industrial  importance.  Owing  to  the  somewhat  powerful 
action  of  most  of  the  agents  employed  for  the  purpose,  it  will  appear 
that,  unless  care  and  discretion  are  applied  to  their  use  on  the  part  of 
the  bleacher,  something  more  than  a  destruction  of  the  coloring  matter 
will  occur, — a  probable  partial  destruction  of  the  fibre.  The  operation 
has  been  known  since  the  earliest  times;  the  white  linens  of  the  Egyp- 
tians and  Phoenicians  were  much  esteemed  by  the  nations  trading  with 
them.  In  the  early  part  of  the  eighteenth  century  immense  fields  were 
given  up  wholly  to  bleaching  in  the  United  Kingdom;  the  process  as 
carried  out  required  several  months,  consisting  of  a  successive  treatment 
of  the  cloth  or  fabric  in  alkaline  solution — termed  "  bucking  " — and 
washing,  then  exposing,  while  damp,  and  spread  out  on  the  grass  to  the 


BLEACHING. 


523 


sunlight  for  a  few  weeks  (croft- 
ing}, immersing  in  sour  milk, 
washing  again,  and  finally  ex- 
posing on  the  grass,  these  several 
operations  being  repeated  until 
the  required  degree  of  whiteness 
is  obtained.  Great  improvements 
in  the  above  tedious  process  re- 
sulted when  the  use  of  sulphuric 
acid  was  substituted  for  the  sour 
milk,  and  chlorine  gas  replaced 
the  lengthy  field  exposure,  this 
latter  being  due  to  M.  Berthollet ; 
but  the  general  use  of  this  sub- 
stance was  not  established  until 
the  manufacture  of  the  now 
familiar  "  chloride  of  lime  "  or 
"  bleach."  Since  then  many 
other  bleaching  agents,  notably, 
hydrogen  peroxide,  have  ap- 
peared, but  whether  they  will 
ever  displace  the  above  is  an  un- 
certainty. 

1.  Cotton  in  the  raw  or  un- 
manufactured state  is  seldom 
bleached,  except  in  the  produc- 
tion of  absorbent  cotton ;  as  yarn, 
however,  it  is  continually.  The 
hanks,  which  have  been  pre- 
viously scoured,  are  worked  in  a 
solution  of  chloride  of  lime 
(chemick)  from  one  to  two  hours, 
washed  well  in  water,  and  passed 
through  dilute  sulphuric  acid 
(1°  Tw.)  for  about  half  an  hour, 
and  finally  well  washed.  These 
operations  can  be  easily  con- 
ducted in  the  ordinary  wooden 
tubs  of  the  dye-house  in  places 
where  much  yarn  does  not  have 
to  be  bleached,  otherwise  special 
arrangements  should  be  pro- 
vided. Cotton  warps  are  simi- 
larly treated,  the  apparatus  em- 
ployed being  a  continuous  (warp) 
dyeing-machine.  Cotton  fabrics 
require  much  care  and  skill,  espe- 
cially those  intended  for  domestic 


Era.  118. 


524  BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 

use  in  the  bleached  condition,  and  also  those  which  are  to  be  after- 
wards dyed  or  printed  with  delicate  shades.  The  method  of  bleach- 
ing, which  has  reached  a  high  state  of  perfection,  is  the  so-called 
"  madder-bleach,"  from  the  fa.ct  that  it  is  employed  on  all  piece 
goods  to  be  printed  with  alizarin.  The  process  detailed  and  illustrated 
below  must  not  be  accepted  as  the  exact  method  followed  in  every  estab- 
lishment,—it  being  remembered  that  nearly  every  bleacher  has  his  own 
modifications  which  he  introduces,  but  all  yield  the  same  result.  The 
operation  of  stamping  or  sewing  on  designating  marks;  sewing  the 
pieces  together  and  singeing, — a  removal  of  the  nap  or  down  from  the 
cloth  by  means  of  a  gas  flame  or  curved  hot  plate  ("  singeing  plate  "), — 
need  not  be  detailed  here;  reference  may  be  had  to  special  works  on 
textile  manufacture. 

Fig.  118  is  a  plan  of  part  of  a  bleach-house  for  cotton  cloth.  The 
goods  being  received,  they  are  passed  through  the  first  washing-machine, 
on  the  left  of  the  figure;  this  operation  has  for  its  object  the  removal 
of  loose  dirt,  grease, — added  to  the  fabric  during  weaving, — and  other 
matters;  usually  the  goods  are  stacked  overnight  in  order  to  allow  an 
incipient  fermentation  to  take  place,  when  they  are  passed  several  times 
through  the  lime-wash  (milk  of  lime)  in  order  to  become  thoroughly  im- 
pregnated with  about  five  per  cent,  of  lime,  this  being  accomplished  by 
means  of  rollers  immersed  in  and  below  the  surface  of  the  lime-bath 
and  a  pair  of  squeezing  or  "  nipping  rollers." 

Following  the  liming  operation  is  the  boiling  ("  bowking  ")  in 
kiers ;  these  are  strong,  wrought-iron  cylindrical  vessels,  provided  with  a 
series  of  pipes,  and  in  some  cases  with  injectors,  which  enable  the  liquids 
contained  in  them  to  circulate  completely  through  the  cloth,  which  is 
previously  introduced  in  the  form  of  a  rope.  Fig.  119  is  a  vertical  sec- 
tion of  a  single  injector-kier,  and  one  well  adapted  for  working  at  low 
pressures.  Reference  being  had  to  the  figure,  the  vessel  being  filled  with 
the  fabric,  which  is  well  laid  in,  the  liquid  is  admitted,  gradually  find- 
ing its  way  to  the  false  bottom,  through  which  it  passes  to  the  injector 
at  a,  where  it  meets  a  steam  current,  which  forces  it  upward  through 
the  large  pipe,  finally  being  admitted  to  the  kier  again  through  the  valve 
6,  repeatedly  following  the  circuit. 

Barlow's  high-pressure  kiers  are  usually  worked  in  pairs,  and  the 
liquid  is  forced  from  one  to  the  other  by  the  aid  of  steam.  This  kier 
has  a  central  perforated  tube,  through  which  the  liquid  passes  to  come 
in  contact  with  the  cloth.  Several  other  forms  of  kiers  are  in  use,  even 
open  kettles  acting  as  such,  the  object  being  the  same  in  each  case. 

The  length  of  time  the  cloth  remains  in  the  kier  varies  considerably: 
in  some  establishments,  where  a  high-pressure  is  used  (forty  to  fifty 
pounds  per  square  inch),  less  time  is  required^, — five  to  six  hours  being 
deemed  sufficient ;  again,  where  a  low-pressure  is  used  (eight  to  twelve 
pounds)  the  goods  are  allowed  to  remain  in  from  ten  to  twelve  hours. 
From  this  boiling  the  pieces  are  washed  in  water,  and  passed  through 
dilute  hydrochloric  acid  (specific  gravity  1.01  =:  2°  Tw.), — the  bath 
being  technically  termed  a  "  sour."  The  pieces  are  slowly  worked  until 


BLEACHING. 


525 


the  lime  is  completely  dissolved,  when  the  goods  are  thoroughly  washed, 
or  until  every  trace  of  acid  is  removed,  when  a  boiling  with  soap  and 
soda  follows  in  kiers  exactly  as  in  the  boiling  previously  mentioned. 
For  each  hundred  pounds  of  cloth  a  resin  soap  is  used,  made  with  five 
to  six  pounds  of  soda  ash  and  one  to  two  pounds  of  resin;  the  soda  is 
dissolved  in  two  gallons  of  water,  the  resin  added,  and  the  whole  boiled 
for  several  hours;  for  each  pound  of  cloth  to  be  acted  upon  one  gallon 
of  water  is  used.  The  time  required  for  this  boil  is  nearly  the  same 

FIG.  119. 


as  in  the  previous  boiling.  When  the  resin  soap  solution  is  run  off,  the 
goods  are  boiled  for  three  or  four  hours  with  a  one  per  cent,  solution 
of  soda,  to  remove  the  soap  and  any  unconverted  resin  remaining,  fol- 
lowed immediately  by  a  wash.  At  this  stage  of  the  process  occurs  the 
real  whitening,  or  bleaching,  of  the  goods, — the  so-called  "  chemick- 
ing," — requiring  much  care,  and  is  performed  with  a  solution  made  by 
dissolving  chloride  of  lime,  allowing  to  settle  and  become  clear,  the 
supernatant  liquor  alone  being  used.  The  strength  of  the  solution, 
varying  from  #°  Tw.  to  2°  Tw.  (specific  gravity  1.001  to  1.01),  being 
used  cold,  or  but  slightly  warmed,  in  the  latter  case  penetrating  the 


526  BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 

cloth  better.  Repeated  passage  of  the  goods  through  a  weak  solution 
is  preferable  to  a  shorter  time  in  a  strong  solution,  the  danger  from 
injury  to  the  pieces  being  less.  The  next  operation  may  be  (not  al- 
ways) a  wash,  and  then  a  souring  in  dilute  (specific  gravity  1.01)  sul- 
phuric acid, — termed  a  white  sour, — after  which  the  goods  are  allowed 
to  remain  for  some  time  in  a  heap,  but  not  long  enough  to  become  dry, 
as  a  tendering  of  the  cloth  will  result ;  this  is  followed  with  a  final  wash 
to  remove  every  trace  of  acid,  passed  through  squeezing  rollers,  and 
over  revolving  cans  heated  by  steam,  to  dry.  The  length  of  time  re- 
quired in  the  above  process  varies ;  if  the  goods  are  to  receive  a  fine  clear 
bleach,  or  are  to  receive  delicate  shades  in  dyeing  and  printing,  four  or 
five  days  may  be  necessary,  but  in  the  event  of  the  goods  being  intended 
for  full  shades,  half  the  time  will  answer. 

Mather-Thompson's  Process. — This  is  one  of  the  newer  processes, 
and  is  admirably  suited  for  warps  and  piece-goods.  The  goods  are 
sewed  together,  or  tied,  in  the  case  of  warps,  subjected  to  the  action  of 
hot  caustic  alkali,  washed,  and  transferred  to  wagons,  the  sides  of  which 
are  of  iron  lattice-work  (cages),  and  pushed  into  a  horizontal  kier,  and 
for  five  hours  acted  upon  by  a  solution  of  caustic  soda  (2°  to  4°  Tw. 
=  specific  gravity  1.01  to  1.02)  delivered  in  a  spray  and  at  a  pressure 
of  four  to  five  pounds.  Without  removing  the  goods  from  the  kier 
they  are  washed  with  hot  water,  removed,  and  rinsed  with  cold  water, 
completing  the  scouring.  The  bleaching  is  carried  out  in  a  continuous 
apparatus  through  the  following  stages: 

1.  Rinsing  with  warm  water. 

2.  First  chemick  bath  (chloride  of  lime  solution,  1°  Tw.  —  specific 
gravity  1.005). 

3.  Passage  through  atmosphere  of  carbonic  acid  gas. 

4.  Washing  with  cold  wrater. 

5.  Worked  through  a  one  per  cent,  soda  solution  at  175°  F. 

6.  Second  washing. 

7.  Second  chemick  (chloride  of  lime  solution  .5°  Tw.). 

8.  Second  passage  through  carbonic  acid  gas. 

9.  Third  wash. 

10.  Through  one  per  cent,  hydrochloric  acid,  or  through  one  per  cent, 
of  a  mixture  of  hydrochloric  and  sulphuric  acid  (2  : 1). 

11.  Final  wash. 

In  this  process  the  real  bleaching  is  effected  by  the  hypochlorous  acid 
liberated  by  the  action  of  the  carbonic  acid  gas  upon  the  calcium  hypo- 
chlorite. 

Lunge's  Bleaching  Process  differs  but  slightly  from  others  using 
chloride  of  lime,  except  that  he  increases  the  bleaching  action  by  the 
use  of  a  small  quantity  of  some  organic  acid, — preferably  acetic. 
Chloride  of  lime  in  contact  with  acetic  acid  forms  calcium  acetate,  with 
evolution  of  free  hypochlorous  acid;  this  gives  up  oxygen  during  the 
bleaching,  leaving  hydrochloric  acid,  wrhich  acts  on  the  calcium  acetate, 
forming  calcium  chloride  and  regenerating  the  acetic  acid.  The  hydro- 
chloric acid  never  being  in  the  free  state  cannot  act  on  the  fibre;  acetic 


BLEACHING.  527 

acid  has  no  action,  even  at  the  high  temperature  or  pressure  used  in 
bleaching. 

Hermite  Process  for  Electrolytic  Bleaching. — This  process  is  prob- 
ably one  of  the  most  successful  yet  brought  forward,  embodying  the  use 
of  electricity,  effecting  the  bleaching  by  the  decomposition  of  a  four  to 
five  per  cent,  solution  of  chloride  of  calcium  (not  "  chloride  of  lime," 
or  "  bleaching-powder  "),  of  magnesium,  or  of  aluminum.  The  elec- 
trolyzed  solution  of  the  salt  employed  is  of  especial  service  in  causing 
the  destruction  of  the  coloring  matter  of  vegetable  fibres,  but,  owing  to 
the  peculiar  effect  of  chlorine  on  wool  or  silk,  it  is  impracticable  with 
them.  Electrolyzed  salt  solutions  are  replenished  by  the  addition  of  a 
quantity  of  salt  equal  to  that  absorbed  by  the  fibres  or  fabrics  when 
withdrawn  from  the  bleach-bath. 

2.  Linen. — This  fibre  is  much  more  subject  to  the  destructive  action 
of  bleaching  agents  than  cotton,  in  consequence  of  which  the  same  process 
is  not  applicable,  and  also  on  account  of  the  greater  amount  of  impuri- 
ties present,  chiefly  pectic  acid.  For  yarns  the  trade  distinguishes  three 
important  grades  of  bleaching, — half,  three-quarters,  and  full  white,  to 
obtain  which  several  operations  are  necessary: 

1.  Boiling  for  three  or  four  hours  in  a  ten  per  cent,  solution  of  soda 
ash,  or  in  a  six  per  cent,  solution  of  caustic  soda.     Wash,  rinse,  and 
pass  through  squeezing  rollers. 

2.  Pass  through  a  .4°  Be.  solution  of  chloride  of  lime,  and  work  or 
reel  one  hour,  and  wash. 

3.  Transfer  to  dilute  sulphuric  acid  for  one  hour  (one  part  acid  to 
two  hundred  parts  water). 

4.  Boil  again  in  a  kier  with  two  per  cent,  caustic  soda. 

5.  Repeat  the  passage  through  chloride  of  lime  and  wash. 

6.  Final  treatment  with  sulphuric  acid  as  in  No.  3. 

The  above  will  produce  a  half-bleach,  -and  by  repeating  the  three 
final  operations  a  full  white  will  be  obtained.  Reeling  is  a  term  par- 
ticularly applicable  to  linen-bleaching,  owing  to  the  way  the  yarn  is 
handled,  the  result  being"  that  the  carbonic  acid  in  the  air  acts  upon 
and  decomposes  the  chloride  of  lime,  setting  free  hypochlorous  acid, 
similarly  to  the  use  of  the  gas  in  the  Mather- Thompson  process. 

Linen  cloth,  despite  many  trials,  still  requires  much  longer  time  to 
successfully  bleach  than  yarn.  It  is  quite  possible  to  bleach  the  cloth 
in  a  comparatively  short  time,  but  the  strength  of  the  fibre  would  be 
weakened.  The  following  outline  of  the  general  process  indicates  the 
successive  stages: 

1.  Liming.     Boil  with  eight  to  ten  per  cent,  for  fourteen  hours  and 
wash. 

2.  Allow  to   remain   in   dilute  hydrochloric   acid    (specific    gravity 
1.012)  for  four  to  six  hours  and  wash. 

3.  Boil  with  resin  soap   (two  pounds  caustic  soda  and  two  pounds 
resin)  for  ten  hours,  followed  immediately  by  a  boiling  for  six  to  eight 
hours  with  one  pound  caustic  soda. 

4.  ' '  Grass. ' '    Expose  on  the  fields  for  a  week-or  more. 


528  BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 

5.  "  Chemick."    Pass  through  chloride  of  lime  solution  of  y2°  Tw. 
for  about  five  hours  and  wash. 

6.  "  Sour."     Steep  in  dilute  sulphuric  acid  1°  Tw.  for  two  to  three 
hours  and  wash. 

7.  Boil  for  four  to  five  hours  with  .5  to  .75  per  cent,  of  caustic  soda, 
wash,  and 

8.  Expose  again  for  four  to  five  days  in  the  fields. 

9.  Second  chemick.     Same  as  No.  5}  only  y\°  Tw.  for  five  hours. 

10.  If  necessary,  rub  with  a  soft  soap  between  ' '  rubbing-boards  ' '  * 
to  remove  brown  spots. 

11.  Expose  again  on  the  grass  as  before. 

The  frequent  exposure  of  the  -goods  on  the  grass  to  the  combined 
action  of  moisture,  air,  and  light  necessarily  dispenses  with  a  certain 
amount  of  the  chloride  of  lime,  besides  allowing  of  a  less  energetic 
action. 

3.  Jute. — A  good  white  on  this  fibre  is  difficult  to  obtain.     Prior  to 
bleaching,  jute  is  scoured  with  a  five  per  cent,  solution  of  sodium  sili- 
cate (soluble  glass)  at  70°  C.,  washed,  and  bleached  with  a  solution  of 
sodium  hypochlorite  containing  about  one  per  cent,  of  available  chlorine, 
made  by  decomposing  bleaching-powder  with  carbonate  of  soda,  settling, 
and  using  the  clear  liquid.     The   goods   are  thoroughly  washed,   and 
treated  in  a  dilute  bath  of  hydrochloric  acid    (y2°  to  1°    Tw.)    and 
washed,  or  they  can  be  further  acted  on  by  sulphurous  acid  by  immers- 
ing in  a  bath  of  sodium  bisulphite  for  two  to  three  hours  and  dried.    Jute 
can  also  be  bleached  by  being  worked  in  a  solution  containing  one  per 
cent,  permanganate  potash  (calculated  to  the  weight  of  its  material)  and 
exposing  to  the  air  until  it  becomes  brown,  when  it  is  immersed  in  a 
solution  of  sulphurous  acid  and  washed. 

4.  Wool. — For  yarns,   the  oldest  practical   method   of  bleaching  is 
"  stoving," — that  is,  an  exposure  of  the  damp  goods  to  the  vapors  of 
burning  sulphur,  confined,  usually,  in  a  frame  building;  in  the  centre 
of  the  floor  is  mounted  an  iron  pot  in  which  roll  sulphur  is  placed,  and 
ignited  by  a  piece  of  iron  heated  to  redness.     From  six  to  eight  per  cent, 
of  sulphur  is  consumed,  and  the  time  required  is  about  eight  hours,  but 
for  carpet  yarns  and  goods  of  a  similar  grade  twelve  hours  may  be 
necessary.     The  yarn  is  removed  and  well  washed,  the  water  containing, 
possibly,  a  little  carbonate  of  soda  to  neutralize  any  sulphurous  acid 
remaining. 

For  piece-goods  the  same  process  is  applicable,  but  it  requires  ar- 
rangements for  passing  the  fabric  over  rollers  inside  the  sulphur-house 
at  a  uniform  rate.  Piece-goods  can  also  be  bleached  according  to  two 
somewhat  lengthy  processes,  embodying  the  sulphuring  in  chambers, 
detailed  in  Sansone's  "Dyeing,"  vol.  i,  p.  123. 

The  wool  bleaching  process  based  upon  the  action  of  the  peroxides  of 
sodium  or  hydrogen  is  the  most  important.  No  metal  should  be  ex- 
posed in  the  wooden  vats  in  which  the  bleaching  is  performed,  and  care 

*  "  Rubbing  boards "  are  two  fluted  pieces  horizontally  placed,  the  upper  of 
which  is  moved  in  opposite  direction  to  the  course  of  the  cloth. 


BLEACHING  AGENTS.  529 

should  be  taken  to  see  that  no  sediment  is  in  the  water-supply  pipe,  all 
such  taking  up  oxygen  from  the  reagent  and  thus  weakening  it.  A  solu- 
tion of  hydrogen  peroxide  (equal  to  about  one  per  cent.,  and  capable  of 
destroying  six  cubic  centimetres  of  decinormal  potassium  permanganate 
solution)  is  made  up  in  the  vat,  and  this  is  carefully  neutralized  with 
silicate  of  soda  which  has  been  previously  diluted  with  warm  water; 
the  yarn  or  goods  is  immersed  and  kept  below  the  surface  of  the  liquid 
by  means  of  a  wooden  lattice  frame.  The  temperature  must  not  be 
above  the  normal.  In  a  few  hours  the  wool  will  be  bleached  to  a  white 
or  nearly  so,  and  by  keeping  it  immersed  a  "  wool  white  "  will  be  ob- 
tained, after  which  the  material  is  lifted,  and  allowed  to  drain  back 
into  the  vat,  when  the  liquid  is  brought  up  to  the  original  strength  with 
fresh  peroxide.  The  bath  can  be  kept  in  use  for  six  months.  After 
draining,  wash  in  water  containing  a  trace  of  sulphuric  acid,  finally 
with  water  alone. 

5.  Silk. — The  preliminary  operations  for  treating  this  substance 
have  already  been  mentioned.  Ordinarily,  silk  is  treated  in  a  similar 
manner  to  wool,  being  hung  on  poles  in  an  atmosphere  of  sulphurous 
acid  for  several  hours  (four  to  six),  taken  down  and  washed;  or  the  silk 
can  be  worked  in  a  bath  of  bisulphite  of  soda,  followed  by  a  weak 
alkaline  wash  and  a  final  rinse.  Aqua  regia  (hydrochloric  acid  and 
nitric  acid,  5  : 1)  of  3°  to  4°  Tw.,  and  at  70°  Pahr.,  is  much  used  for 
small  lots;  the  silk  being  constantly  worked  for  about  twenty  minutes 
when  the  bleaching  is  finished.  For  very  fine  tints,  the  silk  is  entered 
into  a  soap-bath  heated  from  85°  to  105°  Fahr.,  wrung  out,  and  bleached 
according  to  the  peroxide  process  as  indicated  above  for  wool,  but  em- 
ploying solutions  of  greater  strength. 

Tussah  silk  is  always  bleached  with  hydrogen  peroxide,  being  im- 
mersed, as  in  the  case  of  wool,  for  several  hours,  or  even  days.  When 
the  necessary  degree  of  whiteness  is  obtained,  the  silk  is  rinsecl  and  dried. 
Sansone  mentions  immersing  the  silk  in  strong  peroxide,  wringing  out 
the  excess,  and  steaming  in  a  closed  vessel.  This  method  has  yielded 
good  results. 

B.  BLEACHING  AGENTS  AND  ASSISTANTS.  --  Chloride  of  Lime 
("  Bleaching  Powder  "),  the  most  important  agent  for  bleaching  pur- 
poses, is  produced  in  immense  quantities  by  acting  on  dry  slaked  lime 
with  chlorine.  It  occurs  in  commerce  as  a  white  powder  possessing  a 
characteristic  odor  resembling  that  of  chlorine,  and  if  exposed  rapidly 
absorbs  moisture.  The  real  strength  depends  upon  the  amount  of  avail- 
able chlorine  obtainable, — ranging  between  twenty-two  and  thirty-five 
per  cent.  Solutions  of  the  above  sold  under  fanciful  names  are  met 
with  in  the  trade  varying  in  strength  from  five  to  eight  per  cent. 
"  Chlor-ozone  "  is  a  product  considerably  used,  and  is  essentially  a  solu- 
tion of  sodium  hypoehlorite. 

Permanganate  of  Potash  (K2Mn208),  although  not  strictly  a  bleach- 
ing agent,  is  mentioned  on  account  of  its  very  high  oxidizing  properties. 

Hydrogen  Peroxide  (H202)  is  a  colorless,  odorless  liquid  obtained 
by  the  action  of  hydrofluoric  acid  upon  barium  peroxide  in  a  lead-lined 

34 


530  BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 

tank.  The  operation  is  conducted  at  as  low  a  temperature  as  possible, 
and  with  continuous  stirring ;  in  about  twelve  hours  the  reaction  is  over, 
and  the  supernatant  liquid  drawn  off  and  preserved.  The  residue, 
barium  fluoride,  is  decomposed  with  sulphuric  acid,  and  the  hydro- 
fluoric acid  recovered.  It  is  customary  to  refer  to  the  strength  of 
hydrogen  peroxide  as  being  of  so  many  volume  capacity,  six,  ten,  etc. ; 
this  means  that  one  volume  of  the  peroxide  will  yield  six,  ten,  etc.,  vol- 
umes of  oxygen  gas. 

Sodium  Peroxide,  or  Sodium  Dioxide  (Na2O2),  is  now  an  important 
substitute  for  hydrogen  dioxide,  as  it  is  in  many  respects  more  con- 
venient to  use  and  can  be  kept,  when  properly  sealed  from  the  air, 
for  a  long  time.  It  is  a  yellowish-white  powder,  and  can  be  used  in 
alkaline  or  acid  solution. 

Soda  Ash  (Na,CO:i). — This  is  the  commercial  anhydrous  carbonate 
of  soda,  used  principally  in  scouring.  It  is  generally  contaminated  with 
varying  percentages  of  caustic  soda,  sodium  chloride,  sulphate,  etc.  Its 
value  depends  on  the  amount  of  Na20  contained. 

Sal  Soda  (Na2C03.10H2O)  and  Concentrated  Sal  Soda  (Monohy- 
drated,  Na2C03.H20)  are  much  purer  and  more  expensive  carbonates; 
they  contain  no  caustic  soda,  which  renders  them  well  suited  to  scouring. 

Caustic  Soda  (NaOH). — It  comes  in  trade  in  iron  drums — solidly 
filled — or  in  a  coarse  powder.  It  is  obtained  by  treating  carbonate  of 
soda  with  milk  of  lime,  whereby  the  carbonate  is  decomposed  with  forma- 
tion of  calcium  carbonate,  when  the  clear  liquid  is  drawn  off  and  evap- 
orated down  to  the  solidifying  point. 

Carbonate  of  Potash  (K2C03)  is  not  used  in  the  dye  and  bleach 
works  to  the  same  extent  as  soda,  although  for  silk-  and  wool-scouring 
it  leaves  the  yarns,  etc.,  with  a  better  "  feel,"  and  when  used  in  soaps, 
it  does  not  cause  colors  to  run  or  "  bleed  "  to  the  same  extent  as  soda. 
Its  value  depends  upon  the  percentage  of  carbonate. 

Acids. — The  mineral  acids  are  used  in  bleaching  chiefly  to  neutralize 
alkalies,  or  to  cause  a  disengagement  of  hypochlorous  acid  in  the  so- 
called  "  sours,"  and  reference  to  their  production  is  unnecessary. 
Hydrochloric  Acid  of  commerce  (also  called  Spirit  of  Salt,  or  Muriatic 
Acid}  is  yellow  in  color,  due  to  impurities.  The  general  strength  is  21° 
Be.  (specific  gravity  1.17).  Nitric  Acid,  used  in  conjunction  with  the 
above  for  silk-bleaching,  and  largely  in  the  preparation  of  some  mor- 
dants, is  bought  with  a  gravity  of  17.7°  Be.  (specific  gravity  1.140). 
Sulphuric  Acid  (H2S04)  is  obtained  by  the  burning  of  sulphur  and  con- 
ducting the  gas  into  lead  chambers,  in  contact  with  nitrous  vapors  and 
steam.  It  is  a  heavy,  oily-looking  liquid,  and  when  pure  is  colorless.  It 
is  ordinarily  sold  at  66°  Be.  (specific  gravity  1.84). 

Soaps. — The  soaps  employed  in  bleaching,  etc.,  embrace  Tallow, 
Resin,  and  Olive  Oil  (for  silks),  although  others  are  used,  but  mainly 
for  special  purposes.  Reference  to  them  has  been  made  in  the  chapter 
on  Oils  and  Fats.  (See  p.  68.)  In  most  large  establishments  soap- 
boiling  appliances  are  in  use. 

C.  MORDANTS  EMPLOYED  IN  DYEING  AND  PRINTING. — The  process  of 


MORDANTS.  531 

mordanting  is  of  the  utmost  importance,  having  for  its  object  the  pre- 
cipitation of  some  substance  upon  the  fibre  which  has  an  affinity  for, 
and  will  effect  a  more  or  less  complete  fixation  of,  the  coloring  matter 
used  for  the  dyeing.  The  nature  of  the  mordanting  substance  used 
depends  upon  the  character  of  the  fibre,  the  kind  of  dye,  and  upon  the 
effect  sought;  some  shades  require  the  use  of  several.  Under  ordinary 
circumstances  wool  is  simply  boiled  in  a  solution  of  a  metallic  salt,  for 
example,  bichromate  of  potash  ("  chrome  "),  in  the  presence  of  a  small 
quantity  of  some  acid,  in  this  case,  preferably,  sulphuric.  Wool  so 
treated  is  said  to  be  chromed,  and  is  in  a  condition  to  be  dyed  with  log- 
wood or  with  colors  of  the  anthracene  group.  Silk  is  mordanted  simi- 
larly, lower  temperatures,  however,  being  employed.  If  silk  and  wool 
are  immersed  for  a  time  in  a  solution  of  a  metallic  salt,  an  absorption 
will  take  place,  when  the  fibre  can  be  washed  in  water,  during  which 
operation  a  deposition  of  a  basic  oxide  will  occur.  Cotton,  unlike  wool 
or  silk,  has  but  little  natural  affinity  for  the  majority  of  coloring  mat- 
ters, and  of  necessity  must  be  specially  prepared.  It  is  well  known  that 
cotton  has  a  strong  tendency  to  combine  with  tannic  acid,  and  this  is 
made  use  of  by  steeping  cotton  in  a  solution  of  sumach  extract,  catechu, 
or  other  tannin-yielding  material ;  if  it  is  afterwards  washed  and  worked 
in  a  bath  of  some  soluble  metallic  salt,  an  insoluble  compound  will  be 
formed,  which  then  has  the  property  of  uniting  with  the  dye.  It  is  not 
always  necessary  to  prepare  the  cotton  with  tannin,  an  immersion  in  the 
mordant,  followed  by  an  oxidation  or  ageing,  being  deemed  sufficient. 

Substantive  Dyeing  is  where  the  coloring  matter  is  taken  up  from 
its  solution  by  the  fibre  without  the  assistance  of  any  agent.  Wool  and 
silk  are  dyed  with  the  coal-tar  dyes  in  this  manner,  using  some  sulphate 
of  soda  and  sulphuric  acid  in  the  case  of  the  former,  and  with  a  soap- 
bath  and  a  little  acetic  acid  in  the  case  of  the  latter.  Cotton,  when 
dyed  with  the  benzidine  colors,  also  comes  under  this  head;  it  is  possi- 
ble a  colored  compound  of  cellulose  and  the  base  of  the  dye  is  formed. 
The  use  of  salts  in  dyeing  the  above  is  merely  to  prevent  a  too  rapid 
absorption  of  the  dye  by  the  fibre,  thereby  obviating  uneven  shades. 

Adjective  Dyeing  necessitates  the  intervention  of  mordants,  as  above 
explained.  Albumen,  however,  does  not  cause  the  formation  of  an  in- 
soluble precipitate  on  the  fibre,  but  causes  the  cotton  fibre  to  behave 
towards  the  dye  in  a  manner  similar  to  wool.  Many  coloring  matters 
already  fixed  on  cotton  have  the  valuable  property  of  serving  as  mor- 
dants for  other  dyes,  a  property  much  employed  in  the  production  of 
compound  shades. 

The  following  lists  of  mordants  embrace  only  those  of  prominence 
and  in  general  use ;  exact  methods  for  their  manufacture  will  be  found 
in  the  works  of  Hummel,  Sansone,  Herzfeld,  and  others. 

(a)  Mordants  of  Mineral  Origin. — Tin  Mordants-. — These  are  first  in 
importance  to  the  dyer  and  printer.  They  are  used  in  two  states  of 
oxidation,  stannous  and  stannic.  The  former  salts  have  a  great  affinity 
for  oxygen,  a  property  of  considerable  value  as  a  discharge  for  other 
colors.  Their  solutions  are  colorless  or  nearly  so,  except  those  prepared 


532  BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 

with  nitric  acid,  which  are  yellowish, — due,  possibly,  to  an  incomplete 
oxidation  of  the  tin.  The  most  prominent  tin  compound  is  Stannous 
Chloride, — when  crystallized,  "  tin  crystals,"  or  as  a  liquid  known  as 
"  single  muriate  of  tin,"  or  "  double  muriate  of  tin,"  according  to  the 
gravity.  The  crystals  are  obtained  by  dissolving  feathered  tin  in  com- 
mercial hydrochloric  acid  and  evaporating;  good  samples  contain  about 
fifty  per  cent,  of  metal.  The  impurities  are  iron,  lead,  and  sometimes 
copper.  Stannic  Chloride  (SnCl4)  is  of  great  importance  not  as  a  mor- 
dant but  to  the  silk  dyer  as  a  weighting  agent.  It  is  produced  in  im- 
mense quantities,  and  sold  under  the  name  of  "  dynamite." 

Tin  Spirits,  owing  to  the  advent  of  the  tar-colors,  are  much  less  used 
than  formerly.  Their  composition  was  exceedingly  variable,  consisting 
usually  of  stannous  chloride,  with  or  without  additions  of  sulphuric, 
oxalic,  tartaric,  and  nitric  acids,  and  they  bore  such  names  as  Amaranth 
Spirit,  Yellow  Spirit,  Finishing  Spirit,  etc.  "  Stannous  Nitrate  " 
(nitrate  of  tin)  is  essentially  a  solution  of  tin  in  nitric  acid,  the  chemical 
composition  of  which  is  doubtful.  "  Tin  spirits  "  is  a  collective  name 
for  a  long  list  of  stannic  compounds,  made,  usually  by  the  dyer,  by  the 
aid  of  hydrochloric  and  nitric  acids,  sodium  and  ammonium  chlorides, 
etc.  They  are  no  longer  used.  Stannate  of  Soda,  or  Preparing  Salt,  is 
used  in  cotton-  and  woollen-printing ;  its  value  depends  upon  the  amount 
of  stannic  oxide  contained. 

Alumina  Mordants. — Sulphate  of  Aluminum,  also  known  as  Patent 
Alum,  does  not  find  much  application  in  the  dye-house,  except  in  con- 
nection with  the  tin  weighting  process  for  silk,  on  account  of  its  value 
in  causing  a  plumping  of  the  fibre.  It  is  obtained  from  the  mineral 
bauxite,  and  from  cryolite.  The  brand  manufactured  for  paper-makers 
is  the  purest,  containing  but  little  or  no  iron.  By  the  addition  of 
alkaline  carbonates  the  normal  aluminum  sulphate  is  changed  into  a 
basic  sulphate  which  yields  alumina  to  the  fibre  more  readily.  Their 
application  to  cotton  is  followed  by  a  treatment  with  ammonia  or  soap 
to  fasten  the  alumina  more  fully,  to  wool  generally  with  cream  of 
tartar,  and  to  silk  by  immersion  overnight  in  the  solution,  followed  by 
a  washing,  which  causes  the  formation  of  a  basic  salt.  Aluminum 
Acetate,  or  "  Red  Liquor," — so  called  from  the  original  use  to  which  it 
was  put,  dyeing  reds, — is  obtained  by  the  double  decomposition  of 
aluminum  sulphate  and  calcium  or  lead  acetate  in  the  proper  propor- 
tions, and  using  the  supernatant  liquid.  Professors  Liechti  and  Suida, 
and  Kochlin  have  conducted  elaborate  researches  into  the  action  of  the 
aluminum  compounds  as  mordants,  and  their  results  have  thrown  much 
light  upon  the  whole  subject  of  mordanting.  Sulpho-acetate  of  Alumina 
is  obtained  when  an  insufficient  quantity  of  the  acetate  (lead  or  cal- 
cium) is  added  to  decompose  the  alumina  salt,  and  this  forms  the  red 
liquor  of  trade.  Ordinarily,  the  solutions  have  a  dark-brown  color  and 
are  characterized  by  a  strong  pyroligneous  odor.  The  cotton-dyer  and 
printer,  especially  the  latter,  make  considerable  use  of  this  mordant, 
for  reference  to  which,  see  p.  548.  The  remaining  alumina  compounds 
— viz.,  chloride,  nitrate,  hyposulphite,  oxalate,  etc. — are  but  little  used, 
chiefly  in  calico-printing  for  alizarin  shades. 


MORDANTS.  533 

Iron  Mordants. — Like  tin,  iron  is  employed  in  two  states  of  oxida- 
tion,— ferrous  tand  ferric.  Ferrous  Sulphate  (FeS04.7H20),  Copperas, 
or  Green  Vitrol,  occurs  as  a  by-product  from  several  chemical  processes, 
and  is  much  used  in  cotton-dyeing,  and  in  the  preparation  of  iron 
mordants.  Ferrous  Acetate,  also  called  Pyrolignite  of  Iron  and  Black- 
iron  Liquor,  is  manufactured  similarly  to  the  acetate  of  alumina,  or  by 
dissolving  scrap-iron  in  crude  acetic  acid.  It  is  applied  in  the  same 
general  manner,  and  to  the  same  fibres,  as  the  alumina  compound.  The 
remaining  iron  mordants  are  the  Nitrates  and  the  Nitro-sulphates.  The 
former  are  obtained  by  dissolving  scrap-iron  in  nitric  acid  to  the  proper 
degree  of  saturation,  and  the  latter,  by  treating  copperas  with  nitric 
acid;  as  an  iron  mordant  for  black  on  silks  and  as  a  weighting  agent 
for  black  silks,  this  latter  is  probably  the  best,  from  the  fact  that  the 
iron  exists  in  both  states  of  oxidization. 

Chromium  Mordants  comprise  among  the  most  important  Bichromate 
of  Potash  and  Bichromate  of  Soda,  both  being  products  obtained  from 
chromite.  The  former  is  well  crystallized,  the  latter  is  quite  deliques- 
cent, frequently  becoming  fluid;  in  price  it  is  cheaper  than  the  potash 
salt,  and  yields  the  same  results.  It  is  a  valuable  wool  mordant,  and  is 
also  much  used  as  an  oxidizing  agent.  Chrome  Alum  (Potassium 
Chromium  Sulphate)  is  a  residue  from  the  manufacture  of  alizarin,  and 
is  employed  as  the  basis  for  producing  many  of  the  chromium  mordants. 
Chromium  Acetate  is  obtained  by  double  decomposition  of  lead  acetate 
and  chromium  sulphate,  and  in  commerce  it  is  found  of  about  30°  Tw. 
(specific  gravity  1.15).  It  is  used  in  printing.  Other  compounds  used 
are  the  chloride,  sulphate-acetate,  and  alkaline  chromhydroxide  solution. 

Copper  Mordants  are  well  represented  by  the  sulphate  (blue-stone) 
and  the  nitrate.  Sulphate  of  Copper  is  used  in  dyeing  blacks,  mostly 
in  conjunction  with  other  mordants,  and,  owing  to  its  cheapness,  is  used 
for  the  production  of  nearly  all  the  copper  compounds.  Nitrate  of 
Copper  is  easily  prepared  by  dissolving  scrap-copper,  not  brass  (as 
free  from  lead  and  solder  as  possible),  in  nitric  acid,  and  diluting  to 
1.4  specific  gravity.  In  cold  weather  good  crystals  are  obtained,  but 
they  absorb  moisture  very  rapidly.  The  sulphide  and  acetate  find  little 
application  except  in  special  cases. 

Antimony  Mordants. — Tartar  Emetic  (Antimonial  Potassium  Tar- 
trate)  is  the  best  known  of  this  group,  and  is  much  used  for  fixing  tannin 
in  cotton-dyeing.  Oxy chloride  of  Antimony  is  another  form,  used  for 
the  same  purpose.  These  products  have  been  practically  displaced  by  the 
double  fluorides  of  antimony  and  potassium  and  of  sodium  which  have 
been  brought  on  the  market  as  more  convenient  and  desirable.  They 
are  well  crystallized,  easily  soluble,  and  cheaper.  The  mode  of  applica- 
tion is  the  same  as  for  other  antimony  salts. 

Other  mordants  besides  those  above  mentioned  are  used,  but  not  as 
extensively,  and  enough  has  been  said  to  indicate  their  general  nature; 
under  the  operations  of  dyeing  the  special  uses  to  which  they  are  applied 
will  be  mentioned. 

(&)  Mordants  of  Organic  Origin. — Tannin  (Tannic  Acid)  is  now 
produced  in  large  quantities  of  exceptional  purity  for  use  in  the  arts, 


534  BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 

and  offers  to  the  dyer  a  convenient  mordant  in  place  of  many  tannin- 
yielding  substances,  which,  however,  still  hold  their  position  on  account 
of  other  properties.  Tannin  is  much  used  by  the  cotton-dyer,  and  is 
applied  generally  in  two  ways:  first,  by  steeping,  and,  second,  by  pad- 
ding. For  silk,  tannin  is  extensively  used  in  the  production  of  blacks, 
and  also  for  weighting.  Catechu,  or  Cutch  (see  p.  497),  is  used  in  a 
similar  manner  to  tannin,  for  the  production  of  browns,  drabs,  blacks, 
and  other  shades,  in  combination  with  bichromate  of  potash,  copper, 
iron,  etc.  Catechu  is  bought  in  mats  weighing  about  one  hundred  and 
fifty  pounds,  and  also  as  "  cutch  extract,"  or  "  prepared  cutch,"  made 
by  dissolving  the  crude  cutch,  straining  from  sticks,  stone,  etc.,  and 
evaporating  to  about  51°  Tw.  It  is.  used  for  wool  and  for  silk.  Sumach 
(Shumach)  is  used  in  the  dye-house  in  the  ground  state,  and  as  an  ex- 
tract, which  is,  in  some  instances,  grossly  adulterated.  Nutgalls,  rich 
in  tannin,  find  extensive  application  both  in  dyeing  and  printing,  espe- 
cially when  light  shades  are  to  be  fixed.  They  occur  whole,  ' '  crushed, ' ' 
and  as  an  extract,  which  comes  usually  of  two  qualities.  Myrobalans, 
kino,  divi-divi  (see  pp.  359  and  360),  etc.,  are  also  employed. 

D.  DYEING. — The  apparatus  used  by  the  dyer  consists  of  vats, 
kettles,  cisterns,  etc.,  which  are  ordinarily  constructed  of  wood, 
although  they  may  be  also  of  copper  or  similar  metal,  and  even 
stone.  Their  capacity,  in  case  of  woollen  yarn,  is  such  that  they 
can  conveniently  accommodate  a  hundred  pounds  of  material,  although 
the  sizes  vary  according  to  circumstances.  Wooden  kettles  are  heated  by 
a  copper  steam-coil  inside  and  on  the  bottom,  and  are  provided  with  a 
•  water-supply  pipe,  and  a  lifting  plug- valve  for  emptying.  Metal  ket- 
tles are  preferably  heated  with  steam  by  a  coil  or  double  bottom.  The 
shapes  of  the  vat  or  kettle  vary  with  the  material  to  be  dyed.  For  cot- 
ton, wool,  and  silk  yarns  they  are  mostly  rectangular,  and  of  varying 
depth,  for  loose  material,  mostly  circular;  in  the  case  of  indigo-vats 
for  yarns,  they  are  wine-pipes  stood  on  end;  this  gives  a  great  depth  of 
liquid  with  a  minimum  of  exposure.  In  hand-dyeing,  the  yarn  is  hung, 
and  worked  on  sticks  laid  across  the  top  of  the  kettles;  piece-goods  are 
worked  by  means  of  a  movable  winch.  Loose  material  is  dyed  as  such 
in  circular  tubs,  warps  are  passed  over  a  series  of  rollers  immersed  in 
the  dye-liquor,  and  then  between  squeezing  or  nipping  rollers.  Machine 
or  apparatus  dyeing  is  rapidly  gaining  in  favor.  Two  general  systems 
are  in  use:  (1)  Pack  system,  where  the  material  is  tightly  packed  in  a 
vessel  and  the  dye-color  forced  through  it,  and  (2)  Loose  system,  where 
the  material  is  moved  through  the  dye-liquor. 

Of  primary  importance  in  successful  dyeing  is  a  regular  supply  of 
pure  water,  and  in  the  absence  of  this,  various  means  must  be  resorted 
to  to  purify  the  water  at  hand,  which  may  be  contaminated  with  sewage, 
which  may  not  render  it  unfit  for  use,  or  else^t  may  contain  lime  or 
magnesia,  usually  as  bicarbonates,  which  are  soluble,  or  it  may  have 
sulphates  or  chlorides.  Iron  (when  present  it  is  as  a  bicarbonate)  is 
very  objectionable,  and,  for  some  operations,  prevents  the  use  of  the 
water.  Water  which  has  flowed  through  limestone  regions  will  in- 


DYEING.  535 

variably  be  hard  from  the  lime  dissolved,  and  that  which  flows  or  is 
pumped  from  granitic  regions  will  be  soft,  due  to  the  absence  of  lime, 
etc.  In  the  event  of  water  having  suspended  matter,  this  can  be  easily 
removed  by  suitable  filtration,  but  if  other  impurities  are  present, 
chemical  purification  should  be  resorted  to.  A  hard  water  is  one  which 
has  bicarbonate  of  lime  or  magnesia  dissolved,  this  solution  being  really 
a  dissolving  of  carbonate  of  lime  in  carbonic  acid  contained  in  the 
water;  besides  the  above,  it  may  contain  in  solution  sulphates  of  lime 
or  magnesia.  A  water  containing  no  sulphates,  if  boiled,  would  lose 
its  hardness  by  the  b ^carbonate  splitting  off  into  carbonic  acid  gas  and 
carbonate  of  lime  or  magnesia,  which  would  be  precipitated  (temporary 
hardness)  ;  if  sulphates  were  present,  the  boiling  would  have  no  effect  on 
them  (permanent  hardness).  A  soft  water  is  one  containing  no  such 
impurities. 

Chemical  Purification  for  water  embraces  several  processes,  notably 
Dr.  Clark's:  decomposing  the  bicarbonate  with  a  clear  solution  of  cal- 
cium hydroxide,  by  this  means  the  excess  of  carbon  dioxide  is  combined 
with  the  lime  added,  which  is  precipitated  and  removed  by  settling. 
Only  the  temporary  hardness  is  removed.  The  Porter-Clark  process  is 
similar  to  the  above,  with  the  exception  that  the  precipitates  are  re- 
moved by  the  water  being  passed  through  a  filter-press.  Caustic  Soda 
is  also  used  as  a  purifying  agent,  which  removes  both  the  temporary 'and 
permanent  hardness.  The  water  will  then  be  slightly  alkaline.  Alum 
and  sulphate  of  alumina  are  extensively  used  in  water  purification  for 
dyeing  purposes.  The  alumina  compound,  if  added  to  a  water  in  suitable 
quantity,  is  completely  eliminated  by  combining  and  separating  with 
the  impurities. 

Solution  of  Coal-tar  Colors  requires  a  little  care,  because  if  imper- 
fectly done  the  yarn  or  fabric  will  be  spotted  or  striped :  effects  exceed- 
ingly difficult  to  remove.  The  colors  are  dissolved  readily  in  warm 
water;  some  may  require  almost  a  boiling  temperature,  while  others  are 
injured  when  highly  heated.  They  ought  never  be  over  a  direct  fire. 
In  all  cases  it  is  well  to  strain  through  felt. 

Cotton-dyeing. — Two  operations  are  necessary,  mordanting  and  dye- 
ing, except  in  indigo-dyeing,  where  no  mordant  is  required,  and  in  the 
application  of  the  substantive  and  primuline  colors.  In  the  case  of  raw 
stock,  the  operations  are  conducted  in  large  circular  or  rectangular  vats, 
heated  as  previously  described,  and  provided  with  the  necessary  inlets 
and  outlets  for  water,  the  outlet  being  covered  with  a  gauze  screen  in 
order  to  keep  the  loose  material  from  stopping  it  up.  The  material  is 
"  poled  "  or  worked  by  long-handled  rakes  or  by  mechanical  means. 
The  washing  can  be  done  in  a  similar  apparatus,  or  in  one  similar  to  a 
wool-scouring  machine.  For  yarns,  besides  the  open  kettles  mentioned 
on  the  preceding  page,  many  mechanical  devices  are  in  use,  and  are  well 
suited  where  large  quantities  of  material  are  to  be  worked  to  one  shade, 
but  in  cases  where  different  shades  are  to  be  produced,  hand-dyeing 
cannot  be  excelled.  For  warps,  the  apparatus  referred  to  on  page  523 
is  used;  it  can  be  made  with  two  or  more  kettles,  so  that  the  warp  can 


536  BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 

pass  through  two  or  more  different  solutions.  This  arrangement  is  ad- 
mirable for  mordanting,  dyeing,  and  washing,  or  in  the  event  of  using 
the  primuline  colors,  requiring  rapid  treatment.  The  several  baths 
can  be  maintained  at  different  temperatures. 

Cloth-dyeing  Machinery. — The  vats  are  either  iron  frames  and  wood 
or  all  wood,  in  some  places  small  enough  to  stand  on  the  floor  of  the 
dye-house,  in  others  they  must  be  sunk  below  that  level,  in  all  cases 
surmounted  with  a  hand  or  power  winch  for  working  the  pieces.  Dry- 
ing is  accomplished  by  wringing  out  the  yarn,  centrifugating,  and  hang- 
ing on  wooden  sticks  in  a  "  dry-room,"  or  in  the  case  of  piece-goods, 
squeezing  through  rollers,  centrifugating,  and  carefully  arranging  on 
sticks  as  above. 

Application  of  the  Natural  Coloring  Matters. — Indigo,  including 
synthetic  indigo. — This  dye  is  always  applied  in  the  cold,  and  by  any 
of  the  several  "  vats  "  now  known,  among  which  the  lime  and  copperas 
may  be  mentioned.  This  vat,  or  series  (usually  ten),  is  made  up  in 
various  proportions,  the  amount  of  ground  indigo  ranging  from  thirty 
to  thirty-eight  pounds,  copperas,  fifty  to  eighty-five,  lime,  eighty  to 
ninety.  The  vats  being  filled  with  water,  the  lime  is  added,  followed  by 
the  ground  indigo  and  the  copperas,  raking  the  whole  up  occasionally 
until  the  indigo  has  been  reduced,  which  is  known  by  the  olive-colored 
appearance  of  the  liquid.  A  good  working  vat  is  known  by  peculiar 
blue  streaks  or  veins  which  appear  when  it  is  raked.  The  dyeing  is 
performed  by  dipping  the  wetted  yarns  in  the  oldest  (weakest)  vat, 
then  squeezed  out,  placed  aside  to  oxidize,  and  passed  through  the  next, 
and  so  on  until  the  proper  depth  of  shade  is  reached,  the  whole  opera- 
tion being  conducted  systematically.  The  lime  which  is  precipitated  on 
the  yarn  is  removed  by  means  of  a  weak  acid  and  washing.  Piece-goods 
are  dyed  in  a  similar  solution  by  fastening  the  material  to  a  large  frame, 
which  is  dipped  and  re-dipped  until  the  proper  shade  is  obtained,  or,  in 
case  of  warps,  also  by  passing  over  immersed  rollers  in  a  large  vat,  and 
finally  over  rollers  exposed  to  the  atmosphere ;  this  is  particularly  suited 
for  light  shades. 

Zinc-powder  is  much  used  in  indigo-dyeing,  supplanting  copperas; 
for  forty  pounds  of  indigo  about  twenty  pounds  of  zinc-dust  are  used. 
This  vat  is  more  economical  than  the  preceding.  Other  vats  are  also 
employed, — viz.,  hydrosulphite,  German  soda  vat,  urine,  etc.,  but  those 
detailed  indicate  sufficiently  the  character  of  the  operation. 

Logwood. — This  dye-wood  is  used  in  the  form  of  liquid  or  solid  ex- 
tracts, and  as  chips,  and  mainly  for  the  production  of  blacks.  The 
cotton  is  mordanted  in  a  cold  solution  of  acetate  or  nitrate  of  iron, 
squeezed,  and  the  iron  precipitated  on  the  fibre  by  passing  through  a 
solution  of  carbonate  of  soda,  and  boiled  in  the  logwood-bath ;  or  the  cot- 
ton is  allowed  to  steep  in  a  solution  of  tannin  •>( sumach,  galls,  etc.)  for 
several  hours,  then  worked  in  dilute  iron  solutions  as  above, — this  pro- 
duces a  tannate  of  iron, — followed  by  a  passage  through  weak  lime-water, 
and  dye  in  a  separate  kettle.  Acetate  of  alumina  can  be  used  with  the 
iron,  somewhat  modifying  the  shade.  A  "  chrome  black  "  can  be  ob- 


DYEING.  537 

tained  by  dyeing  in  a  single  bath  of  bichromate  of  potash,  hydrochloric 
acid,  and  logwood ;  many  modifications  of  this  process  are  known.  Gray 
shades  can  be  obtained  by  first  working  in  logwood,  and  afterwards  in 
the  copperas  or  bichromate  of  potash  baths. 

Of  the  red  dye-woods  little  need  be  said,  as  they  are  now  but  seldom 
used;  their  coloring  matters  are  fixed  in  the  usual  manner  with  tin, 
alumina,  or  iron  mordants.  Of  the  yellows,  Quercitron  Bark  and  Fustic 
are  the  most  important;  the  former,  used  chiefly  as  an  extract,  is  avail- 
able for  the  production  of  greens,  etc.,  in  combination  with  other  color- 
ing matters.  Fustic  is  used  to  shade  logwood  black.  Turmeric  is 
no  longer  used  in  dyeing. 

Application  of  the  Artificial  Coloring  Matters  to  Cotton* — In  this 
section  only  the  individual  colors  will  be  referred  to,  any  attempt  to 
discuss  the  production  of  shades  by  compounding  would  be  beyond  the 
scope  of  this  publication. 

Fuchsine  is  dyed  upon  tannin-prepared  cotton,  or  upon  cotton  that 
has  been  worked  in  small  quantities  at  a  time  in  a  bath  of  ten  per  cent, 
of  neutral  soap  or  Turkey-red  oil,  followed  by  an  immersion  in  a  warm 
bath  of  two  hundred  and  fifty  gallons  water  and  one  gallon  acetate  of 
alumina  (9°  Tw.).  Work  half  an  hour,  wash,  pass  through  a  soap- 
bath  for  fifteen  minutes,  wash,  squeeze,  and  dye.  The  color  is  added  in 
successive  portions  until  the  required  shade  is  obtained.  Safranine  is 
dyed  upon  a  tannin  mordant,  or  the  tanned  material  is  worked  in  a  3° 
Tw.  bath  of  stannous  chloride  for  an  hour,  washed,  and  passed  through 
a  two  per  cent,  soap  solution,  and  dyed  at  140°  F.  Methyl  and  allied 
Violets  can  be  dyed  upon  tannin  as  above,  or  pass  the  untanned  cotton 
through  a  one  per  cent,  olive-oil  bath,  squeeze,  and  dye  at  100°  F.,  or 
with  the  assistance  of  acetate  of  tin,  or  with  alum  and  soda.  The  basic 
greens,  including  Victoria  Green,  Methyl  Green,  Brilliant  Green,  etc., 
are  easily  dyed  upon  cotton  in  the  ordinary  manner  with  a  little  (.5  per 
cent.)  acetic  acid. 

The  Eosins,  with  Phloxin,  etc.,  are  dyed  in  several  ways:  first,  by 
passing  the  cotton  through  a  two  per  cent,  soap-bath,  followed  by  an 
immersion  for  two  hours  in  from  two  to  three  per  cent,  acetate  of  lead, 
washing  well,  and  dyeing,  cold,  with  a  little  acetic  acid;  or,  second,  by 
working  in  a  dye-bath  with  eight  to  ten  per  cent,  sulphate  of  soda,  or 
the  cotton  can  be  worked  in  5°  Tw.  bath  of  stannate  of  soda  for  an  hour, 
worked  for  thirty  minutes  in  a  ten  per  cent,  alum  solution,  rinsed,  and 
dyed  cold.  Rhodamin  is  dyed  on  acetate  of  alumina  exactly  as  for 
fuchsine.  Brilliant,  Cotton,  and  Soluble  Blues.  The  cotton  is  tanned 
and  dyed  with  five  per  cent,  alum  and  one  per  cent,  soda;  or  the  tanned 
cotton  can  be  worked  in  a  3°  Tw.  stannous-chloride  bath  for  an  hour, 
rinsed,  and  dyed  at  150°  F.  If  light  shades  are  to  be  produced,  work 
the  cotton  in  a  five  per  cent,  soap-bath  for  an  hour,  squeeze,  and  work 
in  a  three  per  cent,  tannin-bath,  wring  out,  and  dye  with  the  assistance 

*  Reference  has  been  made  in  the  preparation  of  this  and  subsequent  sections 
on  its  application  to  several  of  the  published  trade  circulars  issued  by  the  coal- 
tar  color  manufacturers,  and  also  to  information  from  private  sources. 


538  BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 

of  tartaric  acid  and  alum.  Victoria  Blue.  Cotton  is  mordanted  with 
tannin;  dye  with  one  per  cent,  acetate  of  alumina.  Methylene  Blue. 
This  is  an  exceedingly  valuable  color  to  the  cotton-dyer,  as  with  it  he 
can  produce  indigo  shades.  The  cotton  is  mordanted  with  twenty-five 
per  cent,  sumach  at  160°  F.  Give  several  turns,  and  allow  to  steep 
ten  hours,  wring*  out,  and  work  for  twenty  minutes  in  two  and  one- 
half  per  cent,  tartar  emetic,  wash,  and  dye  in  a  bath  prepared  with 
acetic  acid  (three  per  cent.)  at  75°  F.,  gradually  raising  the  tempera- 
ture to  160°  F.  Croce'in  Scarlets  are  dyed  on  cotton  by  working  the 
untanned  yarn  in  stannate  of  soda,  wring,  and  pass  for  half  an  hour 
through  sulphate  of  alumina,  rinse,  and  dye.  Cotton  can  also  be  dyed 
by  passing  first  through  stannic  chloride,  and  then  through  acetate  of 
alumina.  Dye  cold,  or  dye  direct,  with  sulphate  of  alumina.  Auramin, 
of  considerable  value,  is  dyed  in  the  same  manner  as  methylene  blue. 
Bismarck  Brown  and  Chryso'idine.  Dye  same  as  safranine;  tempera- 
ture 100°  F.  Induline  and  Nigrosine.  Dye  in  same  manner  as  for  the 
cotton  blues.  Paraphenylene  Blue  is  dyed  upon  tin  or  antimony,  and 
tannin.  The  shades  produced  are  very  dark,  and  extremely  fast; 
treated  with  bichromate  of  potash,  the  shade  closely  imitates,  and  is 
faster  than,  indigo.  The  substantive  colors  of  the  Congo  and  parallel 
groups  are  exceedingly  valuable,  for  the  reason  that  they  are  easily 
dyed  upon  unmordanted  cotton,  and  that  they  are  of  exceptional  fast- 
ness. The  several  Congos,  Benzo-  and  Delta-purpurin,  and  Rosazarin, 
are  dyed  with  two  and  one-half  per  cent,  soap  and  ten  per  cent,  sul- 
phate of  soda,  or  phosphate  of  soda,  boil  for  one  hour.  Hessian  Purple 
is  dyed  at  a  boil  for  half  an  hour  with  ten  per  cent,  common  salt,  fol- 
lowed by  a  passage  through  dilute  soda.  Chrysamin  is  dyed  with  ten  per 
cent,  sulphate  of  soda  and  two  and  one-half  per  cent,  soap  at  a  boil. 
Hessian  Yellow  is  dyed  with  ten  per  cent,  of  salt  and  a  little  Turkey-red 
oil.  Brilliant  Yellow  and  Chrysophenin  are  dyed  with  ten  per  cent,  salt 
and  two  per  cent,  oxalic  acid,  work  half  an  hour,  squeeze,  rinse,  and 
dry.  Azo  Blue,  and  Benzoazimine,  Heliotrope,  etc.,  are  dyed  with  ten 
per  cent,  sulphate  or  phosphate  of  soda  and  two  and  one-half  pounds 
of  soap,  let  stand,  and  skim  the  surface,  add  the  dye,  boil,  and  put  in 
the  yarn,  and  work  for  an  hour,  boiling,  rinse  the  yarn,  and  dry  at  as 
low  a  temperature  as  possible.  Indigo  shades  from  Benzoazimine  are 
obtained  as  above,  but  for  every  one  hundred  parts  of  color  add  three 
parts  Chrysamin.  All  the  substantive  dyes  act  as  mordants  for  a  very 
large  number  of  other  colors,  no  other  fixing  agent  being  required. 
Diazotized  and  developed  colors  for  cotton,  of  which  primuline  is  the 
type  are  dyed  in  the  usual  way  for  a  substantive  color,  then  "diazo- 
tized  "  in  a  bath  of  nitrite  of  soda  and  a  mineral  acid,  and  afterwards 
"  developed  "  by  passing  through  a  bath  containing  a  developer,  e.g., 
/3-naphthol,  which  develops  and  fixes  the  colors.-  Dark  blues  and  blacks 
are  largely  dyed  by  this  process  specially  for  hosiery,  on  account  of  the 
fastness.  CSee  p.  541.) 

The  important  group  of  sulphur  colors  dye  cotton  various  shades, 
the  most  important  being  the  blacks,   blues   including  indigo   shades, 


DYEING.  539 

cutch  shades  and  olives.  Cotton  is  dyed  from  alkaline  dye  baths  pre- 
pared with  sodium  sulphide,  common  salt,  and  the  necessary  color.  The 
shades  are  noted  for  their  fastness  except  to  chlorine. 

Another  important  group  of  cotton  colors  are  the  so-called  "  vat 
dyes  "  which  dye  cotton  from  baths  containing  the  coloring  matter  in 
a  reduced  state,  similar  to  indigo.  The  range  of  shades  is  very  exten- 
sive, possessing  very  good  fastness  to  general  influences,  including 
chlorine. 

Aniline  Black. — This  color  is  produced  directly  upon  the  fibre  dur- 
ing the  dyeing  by  means  of  aniline  oil  in  the  presence  of  oxidizing 
agents ;  to  obtain  good  results  it  is  necessary  that  the  oil  used  should  be 
as  pure  as  possible.  Two  methods  are  in  general  use, — warm  (Grawitz 
patent)  and  the  cold.  In  the  former  method,  two  thousand  four  hun- 
dred litres  of  water,  thirty-two  kilos,  hydrochloric  acid,  sixteen  kilos, 
bichromate  of  potash,  and  eight  kilos,  aniline  oil  are  taken.  The  acid 
and  aniline  are  each  diluted  with  water  and  carefully  mixed,  the  solu- 
tion thus  obtained  being  added  to  the  main  volume  of  water.  The  bi- 
chromate of  potash  is  previously  dissolved  and  added  after  the  aniline. 
Immerse  the  cotton,  and  work  for  three-quarters  of  an  hour  in  the  cold, 
and  then  gradually  raise  the  temperature  to  60°  or  70°  C.  In  the 
cold  method  take  eighteen  kilos,  hydrochloric  acid,  eight  to  ten  kilos, 
aniline  oil,  twenty  kilos,  sulphuric  acid,  66°  Be.,  fourteen  to  twenty 
kilos,  bichromate  of  potash,  and  ten  kilos,  copperas.  This  bath  is  made 
up  similarly  to  the  previous  one,  with  the  exception  that  much  less 
water  is  used.  Aniline  salts  in  solid  form  are  often  used  instead  of 
aniline  oil  and  acid.  The  yarn  is  worked  in  one-half  of  the  materials 
for  an  hour  or  so,  after  which  the  remainder  is  added,  and  the  operation 
carried  on  for  about  one  and  a  half  hours  longer,  followed  by  a  wash- 
ing, and  a  boiling  in  a  soap  solution.  In  either  case,  the  cotton  after 
dyeing  is  subjected  to  a  further  oxidization  with  bichromate  of  potash, 
copperas,  and  sulphuric  acid, — this  having  a  tendency  to  prevent  green- 
ing. Chlorate  of  soda  is  used  considerably  as  an  oxidizing  agent  in  the 
dye-bath.  Vanadium  chloride,  or  vanadate  of  ammonia,  has  been 
recommended  to  be  used  with  a  chlorate  in  place  of  bichromate  of 
potash;  the  proportion  of  the  vanadium  salt  being  to  the  displaced 
bichromate  as  1 :  4000.  Another  method  is  to  produce  the  aniline  black 
in  powder  form,  purify  it,  liberate  the  base,  which  is  dissolved  in  sul- 
phuric acid,  poured  into  water,  and  the  precipitate  formed  thereby  dis- 
solved in  caustic  soda.  This  is  reduced  as  in  the  case  of  indigo,  and 
dyed  in  a  similar  manner. 

Alizarin-dyeing,  Turkey-red  Process. — J.  J.  Hummel,  in  his  "  Dye- 
ing of  Textile  Fabrics,"  1886,  p.  427,  et  seq.,  details  the  emulsion  process, 
which  need  not  be  described  here.  It  may  be  stated,  however,  that 
beautiful  results  have  been  obtained  from  its  use;  the  yarn  passes 
through  fourteen  operations,  as  follows:  boiling  in  soda  and  drying, 
worked  in  an  emulsion  of  oil,  dung,  and  carbonate  of  soda;  passed 
through  the  previous  process  twice  again;  worked  four  times  in  car- 
bonate of  soda,  steeped  in  water,  and  in  carbonate  of  soda,  suma~ched. 


540 


BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 


mordanted  with  alumina,  dyed  with  alizarin  (ten  per  cent.),  sumach, 
and  blood,  cleared  with  carbonate  of  soda,  final  clearing  with  soap  and 
tin  crystals.  To  finish  the  dyeing  requires  about  three  weeks,  but  a 
real  Turkey-red  is  produced.  Except  for  some  grades  of  goods,  it  is 
doubtful  whether  such  a  lengthy  process  would  be  profitable. 

The  following  scheme  of  a  process  represents  the  type  of  a  reason- 
ably short  one ;  it  is  well  to  remember  that  it  can  be  modified  to  a  con- 
siderable extent  without  altering  its  product.  It  is  used  in  several 
establishments  essentially  as  given.  Boil  the  cotton  for  two  hours  in  a 
1.04  specific  gravity  solution  of  caustic  soda,  wash  well  in  water,  dry,  and 
work  in  seven  to  ten  per  cent,  solution  of  Turkey-red  oil,  squeeze,  dry  at 
about  115°  to  120°  F.,  steam  in  a  chest,  mordant  with  acetate  of  alumina 
(red  liquor)  at  80°  Tw.,  and  dry  as  before;  work  for  an  hour  in  a  hot 
bath  of  five  pounds  of  dung  and  eight  to  ten  pounds  of  chalk,  followed 
by  a  good  wash,  and  pass  to  the  dye-bath,  made  up  of  eight  per  cent, 
of  alizarin,  two  per  cent.  Turkey-red  oil,  and  about  one  per  cent,  of 
ground  sumach,  or  equivalent  in  pure  extract.  Enter  cold,  and  slowly 

FIG.  120. 


increase  the  temperature  to  and  maintain  it  at  160°  F.  for  over  half  an 
hour.  Dry,  and  steam  in  the  chest  as  above.  The  final  operation  is  a 
soaping  with  carbonate  of  soda  and  stannous  chloride  as  in  the  above 
emulsion  process. 

An  almost  unlimited  number  of  processes  could  be  given,  but  it  is 
hardly  necessary,  the  principle  remaining  the  same  in  every  case.  For 
full  information  reference  is  made  to  Hummel,  Sansone,  and  Knecht, 
Rawson,  and  Lowenthal.  The  apparatus  used  for  alizarin-dyeing  is 
not  special,  with  the  exception  of  the  machines  for  "  padding,"  the 
material  to  be  dyed  with  the  oils  and  for  working  in  the  liquors;  the 
most  important  is  the  steam-chest,  which  is  essentially  a  large  cylindrical 
wrought-iron  drum  with  cast  ends,  one  of  which  is  provided  with  a  well- 
closing  door.  The  chest,  or  steamer,  is  provided  with  a  steam-supply 
pipe,  gauge,  and  safety-valve.  The  yarn  or  cloth  is  hung  on  sticks 
supported  on  rods  inside,  or,  as  shown  in  Fig.  120,  mounted  on  iron 
carriages.  Some  chests  are  so  built  that  the  yarn  contained  can  be 
turned  while  closed  and  with  the  steam  pressure  on,  which  seldom  ex- 
ceeds four  or  five  pounds. 


DYEING.  541 

Ingram  Red,  a  color  obtained  from  primuline  or  polychromine,  is 
for  some  purposes  a  perfect  substitute  for  Turkey-red,  being  fast  to 
light,  soap,  and  acids.  Primuline  is  dissolved  in  warm  water,  common 
salt  or  sulphate  of  soda  added,  and  the  yarn  worked  in  the  bath  until  a 
good  full  yellow  is  obtained,  when  the  material  is  washed,  and  im- 
mersed in  a  cold  solution  of  nitrite  of  soda  slightly  acidulated  with 
either  hydrochloric  or  sulphuric  acid,  this  causes  a  diazotizing  of  the 
yellow  color,  with  the  production  of  an  unstable  orange  shade ;  the  yarn 
is  lifted  out,  washed  rapidly,  and  at  once  dipped  in  a  warm  solution  of 
fi-naphthol  in  caustic  soda,  when  a  deep-red  color  is  developed.  The 
yarn  is  worked  for  a  while,  and  afterwards  well  washed  in  water.  If 
phenol  or  resorcin  is  substituted  for  the  /8-naphthol,  a  fast  yellow  or 
orange  color,  respectively,  will  be  obtained.  The  diazotized  yarn  is 
very  sensitive  to  the  light:  if  it  is  not  in  a  reasonable  time  developed, 
no  color  will  be  obtained;  this  fact  is  at  the  present  time  experimented 
upon  with  a  view  to  its  possible  use  in  photography. 

A  more  recent  and  still  better  substitute  for  Turkey-red  is  the  azo- 
para-nitraniline  obtained  by  diazotizing  para-nitraniline  C  and  devel- 
oping with  /?-naphthol  and  red  developer  C.  The  cotton  yarn  is  pre- 
ferably first  impregnated  with  the  caustic  soda  solution  of  the  developer, 
made  with  the  addition  of  castor-oil  soap,  and  then  put  in  the  diazotized 
solution. 

Linen. — The  uses  to  which  fabrics  made  of  this  fibre  are  put  demand 
colors  that  shall  be  fast  to  washing,  light,  and  air ;  this  requirement  being 
satisfied  by  alizarin  and  indigo.  The  coal-tar  colors,  as  a  rule,  are  not 
applied,  although  they  can  be  by  treating  the  fibre  in  the  same  manner 
as  cotton. 

Jute,  owing  to  its  peculiar  chemical  structure,  does  not  require  any 
mordanting;  all  basic  colors  can  be  applied  by  simply  boiling  in  a  neu- 
tral bath.  Some  scarlets  and  a  few  of  the  acid  colors  are  fixed  with  the 
assistance  of  a  little  acetic  acid  in  the  dye-bath,  sometimes  with  a  little 
sulphuric  acid  and  alum. 

Wool-dyeing. — Raw  wool  is  dyed  in  the  same  manner  as  raw  cotton, 
in  open  kettles,  or  in  machines  made  for  the  purpose.  Woollen  yarns 
and  cloth  are  similar  in  their  manipulation  to  cotton,  the  apparatus  be- 
ing in  both  cases  nearly  the  same.  Dyeing-machines  for  carpet  yarns 
are  coming  slowly  into  use,  several  forms  being  capable  of  handling  a 
large  quantity  in  comparison  with  hand  labor. 

Some  classes  of  goods,  i.e.,  plushes,  have  cotton  backs, — these  being 
previously  dyed  in  the  hank  and  warp  and  then  woven, — the  face,  or 
pile,  is  afterwards  dyed  in  proper  shade,  care  being  taken  to  select  such 
colors  as  will  have  no  modifying  effect  upon  the  cotton  color.  For  this 
purpose  cottons  dyed  with  aniline  black,  indigo,  or  alizarin  are  best 
suited. 

Natural  Coloring  Matters  applied  to  Wool. — Indigo,  as  extract,  is 
now  but  little  employed  for  dyeing  wool  on  account  of  its  fugitiveness, 
when  now  used  it  is  only  for  its  cheapness.  If  other  coloring  matters 
are  to  be  used  in  connection  with  the  above  for  the  production  of  com- 


542  BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 

pound  shades,  a  neutral  extract  had  better  be  used,  and  the  dyeing 
done  without  the  use  of  acid.  Wool  is  dyed  in  a  vat,  where  exception- 
ally fast  and  full  shades  are  demanded,  especially  for  army  cloth.  Loose 
wool  is  dyed  in  the  so-called  fermentation-vat,  the  wool  being  kept 
below  the  surface  of  the  liquor,  worked  about  by  means  of  long  rakes  for 
a  sufficient  time,  and  taken  out  and  put  in  large  cord  bags,  or  placed 
upon  rope  screens  to  drain  and  oxidize.  It  is  finally  dipped  in  very 
dilute  acid  to  remove  soluble  impurities,  well  washed,  and  dried. 
Woollen  yarn  is  worked  in  vats  exactly  as  in  the  case  of  cotton.  Cloth 
is  worked  in  the  vat  below  the  surface  of  the  liquid,  by  means  of  poles 
with  hooks.  The  best  indigo-dyed  cloth  is  that  made  from  wool  which 
has  been  previously  dyed  in  the  raw  state, — dyed  in  the  wool. 

Logwood. — This  dyestuff  is  the  real  base  of  the  blacks  upon  wool, 
the  most  generally  followed  method  being  with  bichromate  of  potash 
as  a  mordant.  Boil  the  wool  in  a  bath  of  three  per  cent,  bichromate 
and  one  per  cent,  sulphuric  acid  for  an  hour,  lift  out,  rinse,  and  boil 
in  a  bath  (made  with  a  decoction  of  about  forty  per  cent,  chipped  log- 
wood) for  an  hour,  lift  the  wool,  and  add  a  little  extract  of  fustic,  con- 
tinue the  boiling  for  a  half-hour.  Frequently  blacks  of  the  anthracene 
groups  are  used  in  combination  with  logwood  to  give  increased  fastness. 
To  prevent  a  "  greening,"  or  development  of  greenish  tinge  on  exposure 
of  the  goods  to  the  light,  a  coal-tar  color,  such  as  "  cloth  red,"  is  dyed 
on  first,  so  as  to  neutralize  the  effect  of  the  green  shade  which  may  form. 
For  cheap  work  "  one-dip  blacks  "  are  used, — these  consist  chiefly  of  a 
mixture  of  logwood  and  a  mineral  mordant,  iron  or  copper.  Wool  can 
be  mordanted  with  copperas,  copper,  and  cream  of  tartar,  etc.,  followed 
by  dyeing  in  the  logwood,  or  it  can  be  worked  in  the  logwood  first,  fol- 
lowed by  a  "  development  "  in  a  bath  of  ferrous  sulphate  of  iron  and 
copper. 

Logwood  Blue,  for  some  kinds  of  work,  is  an  excellent  substitute  for 
indigo,  full  shades  being  obtained  by  direct  dyeing,  or  by  dyeing  upon 
a  light  indigo  bottom.  Hummel  gives  the  following  method.  Mordant 
the  wool  for  one  to  one  and  a  half  hours  at  100°  C.  with  four  per  cent. 
of  aluminum  sulphate,  four  to  five  per  cent,  of  cream  of  tartar;  wash 
well,  and  dye  in  a  separate  bath  for  one  to  one  and  a  half  hours  at  100° 
C.,  with  fifteen  to  thirty  per  cent,  of  logwood  and  two  to  three  per  cent, 
of  chalk.  The  addition  of  a  little  alizarin  or  tin  crystals  to  the  bath  at 
the  termination  of  the  dyeing  will  cause  the  appearance  of  "  bloom," 
peculiar  to  indigo. 

The  red  woods  are  fast  losing  ground,  although  before  the  introduc- 
tion of  the  artificial  scarlets  and  cardinals  they  were  much  used.  Mad- 
der, likewise,  has  been  superseded  by  artificial  alizarin.  Wool  was  mor- 
danted for  browns  with  bichromate  of  potash  as  for  logwood;  for  reds, 
mordant  with  alum,  or  sulphate  of  alumina,  with  cream  of  tartar 
(argols),  and  boil.  Tin  crystals  and  tartar  produce  a  reddish-yellow. 
These  colors  were  not  brilliant,  but  the  value  of  them  depended  upon 
their  fastness.  The  use  of  Cochineal  is  mainly  for  the  scarlets  obtained 
therefrom.  The  wool  is  mordanted  with  tin  crystals  and  cream  of  tar- 


DYEING.  543 

tar,  washed,  and  dyed  in  a  bath  with  five  to  ten  per  cent,  of  cochineal 
(ground)  for  an  hour.  Another  method  is  to  boil  the  unmordanted 
wool  in  a  bath  of  cochineal,  tin  crystals,  and  potassium  oxalate  for  an 
hour.  For  scarlets  with  a  bluish  cast  (crimsons)  the  wool  is  mordanted 
with  aluminum  sulphate  and  cream  of  tartar,  or  the  wool  can  be  mor- 
danted in  a  bath  containing  tin  crystals,  tartar,  and  aluminum  sulphate, 
followed  by  the  dyeing  in  a  separate  bath.  Copper,  or  iron,  as  a  mor- 
dant will  produce  dark  shades,  and  as  impurities  in  the  dye-baths  will 
have  a  saddening  effect  upon  the  color  obtained.  Fustic  is  largely  used 
in  wool-dyeing,  chiefly,  however,  in  combination  with  other  colors, — 
i.e.,  indigo  extract  to  produce  greens,  olives,  sages,  etc.,  and  always  upon 
mordanted  wool,  using  tin  crystals,  sulphate  of  alumina,  bichromate  of 
potash,  iron,  and  copper.  Quercitron  Bark  is  used  for  the  same  pur- 
pose as  fustic  and  under  the  same  conditions.  Flavin,  a  production  of 
the  latter,  is  used  in  the  same  manner,  its  chief  advantage  is  that  it  is 
much  more  concentrated.  Archil  (Orchil)  as  "  extract,"  liquor,  or 
paste  is  extensively  used  in  the  dyeing  of  carpet  yarns;  it  is  applied 
by  simply  boiling  the  yarn  in  a  bath  with  the  color,  sulphuric  acid,  and 
sulphate  of  soda.  It  is  exceedingly  difficult  to  remove  from  yarn  once 
dyed  with  it ;  a  process  which  will  economically  accomplish  this  is  much 
sought  after  by  manufacturers. 

Application  of  the  Coal-tar  Colors. — As  a  general  rule,  it  may  be 
stated  that  nearly  all  the  soluble  artificial  colors  can  be  dyed  upon  wool 
without  any  special  treatment,  by  boiling  in  a  bath  with  ten  per  cent,  of 
sulphate  of  soda  and  two  to  four  cent,  of  sulphuric  acid.  A  few  excep- 
tions may  be  given:  Alkali  Blue  (Nicholson's  Blue).  The  color  is  dis- 
solved in  carbonate  of  soda,  poured  into  the  dye-bath,  the  wool  entered, 
and  the  temperature  raised  to  the  boil,  keep  boiling  for  a  while,  lift, 
rinse  well,  and  immerse  in  a  bath  of  very  dilute  sulphuric  acid,  when 
the  color  will  be  at  once  developed.  The  Violets  (Hofmann's,  etc.)  are 
dyed  neutral,  or  with  a  little  soap.  Methyl  Green  is  applied  to  wool 
with  borax,  after  having  been  mordanted  with  hyposulphite  of  soda, 
and  hydrochloric  acid.  Auramine  is  dyed  both  neutral  and  acid. 
The  Indulines  are  dyed  neutral,  and  then  boiled  in  dilute  sulphuric 
acid.  Gallein  and  Coerulein  are  dyed  upon  wool  mordanted  with  potas- 
sium bichromate  and  a  small  quantity  of  acetic  acid.  The  application 
of  Alizarin  to  wool  is  exactly  as  for  madder,  the  general  mordant  being 
sulphate  of  alumina  and  tartar  for  reds;  tin  crystals  and  tartar  for 
orange;  potassium  bichromate  and  sulphuric  acid  for  red-browns;  iron 
and  tartar  yield  violet;  and  copper,  shades  of  brown.  The  addition  of  a 
little  lime  to  the  dye-bath  is  necessary  in  case  none  is  naturally  present 
in  the  water. 

Nitro-alizarin  (Alizarin  Orange)  produces  with  several  metallic 
mordants,  applied  as  above,  a  range  of  shades,  which  have  not  reached 
commercial  importance.  Alizarin  Blue  is  dyed  upon  a  chromium  mor- 
dant, and  yields  a  durable  blue,  of  some  value, — for  wool,  the  price  of 
the  dye  is  against  it. 

Alizarin  blues,  such  as  Alizarin  Blue  H  R,  which  are  made  by  com- 


544  BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 

birring  alizarin  or  a  derivative  of  the  same  with  a  base,  such  as  aniline, 
give  various  fast  shades,  and  are  dyed  nearly  the  same  as  the  older 
alizarin  blue  and  alizarin  blue  S,  except  that  the  bath  may  be  exhausted 
with  very  little  or  no  acid. 

The  constant  tendency  to  do  away  with  the  mordanting  processes 
for  wool  dyeing  has  caused  the  development  of  certain  groups  of  dye- 
stuffs,  which  yield  shades  of  extreme  fastness,  and  which  are  produced 
by  dyeing  the  wool  in  the  presence  of  the  chrome  salt,  or  by  dyeing  first 
and  "  fixing  "  the  color  by  adding  the  chrome  to  the  extracted  dye 
baths,  or  after  chroming  in  a  separate  dye  bath.  It  is  instructive  to 
note  that  some  of  the  dyes  which  produce  such  shades  on  wool  are  old 
and  well  known  cotton  substantive  "dyes. 

The  mineral  colors  are  dyed  upon  fibres  through  the  decomposition 
of  metallic  salts,  for  example,  to  dye  Prussian  Blue,  the  wool  is  worked 
in  a  bath  of  red  prussiate  of  potash  and  sulphuric  acid,  and  gradually 
brought  to  a  boil,  squeezed,  rinsed,  and  dried. 

Silk-dyeing. — Silk  has  a  great  affinity  for  the  coal-tar  colors,  with 
which  it  can  be  dyed  without  any  mordant,  although  it  is  customary  to 
employ  a  soap-bath  (boiled-off  liquor)  with  or  without  the  addition  of 
a  weak  acid,  usually  acetic.  If  soap  is  not  used  the  colors  will  appear 
streaky  or  spotted.  For  ribbons,  fancy  dress  goods,  plushes,  etc.,  the 
above  colors  are  solely  employed,  with  the  possible  exception  now  and 
then  of  recourse  to  some  natural  coloring  matter,  the  use  of  the  latter 
being  almost  restricted  to  logwood  for  blacks  and  modified  shades,  in- 
cluding browns.  Silk  is  dyed  in  skeins  or  hanks,  warps,  or  pieces,  this 
latter  including  plushes.  The  machinery  is  of  the  simplest  kind,  em- 
bracing the  kettles,  with  and  without  winches,  washing-machines,  etc., 
and  need  not  be  especially  described. 

Silk  is  not  dyed  with  indigo  (vat  process),  but  indigo  shades  are  ob- 
tained by  using  indigo-carmine.  Black  is  obtained  by  several  processes. 
"Work  the  silk  in  acetate  of  iron  and  wash,  then  in  a  warm  soap  solution, 
followed  by  an  immersion  in  ferrocyanide  of  potash,  washed,  and  worked 
again  in  the  iron-bath,  rinsed  well,  and  steeped  in  a  solution  of  catechu 
or  gambir  for  ten  or  twelve  hours  and  washed.  This  preliminary 
process  is  necessary  in  order  to  insure  a  good  result  if  systematically 
carried  out  and  not  forced.  The  material  is  dyed  in  a  logwood  decoc- 
tion containing  soap. 

To  obtain  heavily  weighted  goods,  for  blacks,  the  process  of  dipping 
in  iron  solution  and  then  in  tannin-containing  liquors  is  often  repeated 
several  times.  A  method  giving  excellent  results,  and  which  is  consider- 
ably used,  is  as  follows:  Wash  the  goods,  and  pass  through  a  bath  of 
nitrosulphate  of  iron,  wash,  and  then  through  a  solution  of  carbonate 
of  soda.  These  two  operations  are  repeated  several  times,  each  time 
causing  the  precipitation  of  more  iron  upon  the  fibre,  and  consequently 
"  weighting  "  the  silk.  "Work  for  some  time  in  a  bath  of  ferroprussiate 
of  potash  and  then  in  a  bath  of  catechu,  followed  with  a  little  "muriate 
of  tin  "  or  tin  crystals,  wash,  and  transfer  to  the  logwood-bath,  which 
may  contain  a  little  extract  of  fustic  to  modify  the  shade  required, 


TEXTILE  PRINTING.  545 

then  to  a  soap-bath.  Every  locality  is  not  suited  to  black  silk-dyeing 
on  account  of  impurities  in  the  water,  careful  purification  of  which  is  a 
special  requisite.  Seal  plushes  are  dyed,  first  in  a  dye-bath  in  the  ordi- 
nary manner,  a  dark-brown  shade,  followed  by  the  application  of  a  black, 
blue-black,  or  other  color,  in  the  form  of  a  paste  thickened  with  starch, 
gum,  or  other  medium,  the  application  of  this  being  done  on  a  machine 
provided  with  revolving  brushes,  and  so  regulated  that  only  the  tip  or 
face  of  the  piece  of  goods  is  coated.  One  important  feature  in  plushes 
of  this  character,  and  also  in  other  kinds  of  silk  goods  which  have  been 
heavily  iron-mordanted,  is  that  the  natural  lustre  of  the  fibre  is  some- 
what destroyed;  this  loss  is  supplied  by  means  of  a  mixture  of  vege- 
table oils  made  into  a  paste  with  starch  or  other  substance,  applied  as 
in  the  case  of  the  tip,  and  steamed  in  an  apparatus  similar  to  that  used 
for  alizarin  red  (p.  540).  The  oil,  usually  a  definite  amount,  is  ab- 
sorbed by  the  silk  fibre  under  the  influence  of  steam,  imparting  a  per- 
manent lustre.  The  goods,  when  removed  from  the  steamer,  are  washed 
to  remove  the  starch,  excess  of  oil,  etc.,  when  they  are  ready  for  other 
operations. 

"Dynamited  "  silk  is  silk  weighted  with  stannic  chloride  (dynamite) 
and  fixed  with  silicate  and  phosphate  of  soda,  and  for  full  fibres  with 
sulphate  of  alumina.  Weighting  may  be  as  high  as  400  per  cent. 

A  class  of  fabrics  similar  to  plush,  but  with  the  pile  of  two  or  even 
three  colors,  much  used  for  carriage-robes,  etc.,  and  dyed  to  imitate  the 
skins  of  animals,  are  prepared  in  the  following  manner:  The  material 
(cotton  in  black  with  silk  pile,  the  former  previously  dyed  a  fast  color) 
is  dyed,  say  a  brown,  in  the  ordinary  manner;  upon  the  fibre  is  then  ap- 
plied a  discharge  made  of  stannous  chloride  solution  and  permanganate 
of  potash.  This  is  so  controlled  that  only  one-half  of  the  fibre  is  acted 
upon.  When  the  effect  is  produced  the  excess  is  washed  off,  rinsed, 
dried,  and,  if  necessary,  a  tip  is  applied,  which  only  dyes  the  very  face 
of  the  pile.  In  this  manner  three  colors  are  obtained  on  each  thread  of 
the  face.  After  treating  as  above,  the  whole  may  be  dyed  a  very  light 
shade,  thereby  producing  modified  effects. 

The  artificial  coloring  matters  are  applied  to  silk  as  previously 
stated.  Nicholson's  Blue  (Alkali  Blue)  is  applied  as  directed  for  wool, 
and  seldom  for  the  production  of  mixed  shades.  Picric  Acid  is  much 
used  for  compounding,  especially  for  greens,  faster  colors  can  be  ob- 
tained by  using  naphthol  yellow  and  indigo-carmine.  The  Eosins  yield 
beautiful  colors,  and  are  applied  in  a  soap-bath  followed  by  a  brightening 
in  dilute  acid.  The  Azo  dyes  are  applied  with  a  neutral  soap-bath. 

The  use  of  Alizarin  with  silk  is  only  in  cases  where  fastness  is  of 
more  importance  than  brilliant  shades.  Alizarin  Black  is  being  much 
used  in  dyeing  mohair  goods  (astrachans),  and  is  applied  in  the  ordi- 
nary manner. 

E.  PRINTING  TEXTILE  FABRICS. — A  brief  outline  of  the  more  im- 
portant "  styles  "  in  use  is  all  that  will  be  attempted  in  this  section, 
from  the  fact  that  the  subject  is  too  extensive  to  enter  into  the  details 
satisfactorily.  The  processes  in  general  are  conveniently  divided  into 

35 


546 


BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 


FIG.  121. 


two  main  groups,   differing  in  the  manner  of  applying  the  colors, — 
namely,  Direct  Printed  Colors  and  Dyed  Colors. 

Direct  Printing  is  done  by  mixing  the  desired  color  with  the  proper 
fixing  agents  and  applying  directly  to  the  fabric  by  means  of  blocks 
engraved  with  the  design,  or  in  a  machine  provided  with  a  cylinder 
upon  which  the  design  is  likewise  engraved;  for  each  color  to  be 
applied  a  separate  cylinder  is  needed.  From  the  above  it  is  obvious  that 
the  color  so  applied  will  appear  only  on  those  portions  of  the  fabric 
brought  in  contact  with  the  design. 

Dyed  Colors  are  obtained  by  printing  different  mordants  upon  the 

cloth,  as  above,  and  fixing  as  for  ordi- 
nary cloth,  and  then  dyeing  the  whole, 
or,  by  printing  upon  the  cloth  resists, 
substances  which  will  prevent  the  dye 
from  becoming  fixed  at  those  places  so 
printed,  or,  again,  by  dyeing  the  Avhole 
pieces  first,  and  then  producing  patterns 
or  designs  by  means  of  substances  which 
will  destroy  the  ground-color  whenever 
brought  in  contact;  these  substances  are 
called  discharges.  This  broad  definition 
is  deemed  sufficient  for  the  purpose  in- 
tended ;  the  principle  of  each  style  will 
be  apparent  upon  following  the  methods 
hereafter  given. 

The  operations  conducted  in  a  print- 
works embrace  as  a  preliminary  bleach- 
ing, the  details  of  which  are  referred  to 
on  p.  524.  Then  the  preparation  of  the 
colors,  which  is  always  done  in  copper 
pans  mounted  in  such  a  manner  that 
they  can  be  emptied  easily,  and  that 
their  contents  can  be  boiled  by  steam, 
and  cooled  by  water,  facilities  for  this 
being  done  by  means  of  steam  and  water 
trunnions  connecting  with  the  double 
bottom  of  each  pan.  From  five  to 
eight  pans  are  supplied  in  a  "  bat- 
tery," although  it  is  often  convenient  to  have  one  or  more  pans 
separately  mounted,  and  without  steam  taps.  The  agitation  of  the 
contents  is  performed  either  by  means  of  wooden  paddles  or,  preferably, 
by  mechanical  agitation,  which  can  be  raised  clear  above  the  top  of  the 
pan,  and  without  interfering  with  the  working  of  the  others.  As  the 
majority  of  colors  used  are  made  with  either  search  or  flour  for  thicken- 
ing, it  is  necessary,  to  insure  good  results,  that  they  are  strained  or  fil- 
tered; for  this  purpose  it  is  well  to  have  wooden  frames  made,  over 
which  is  tacked  brass  or  copper  wire  cloth  (iron  is  inadmissible).  The 
most  important  piece  of  apparatus  is  the  printing-machine,  an  idea  of 


TEXTILE  PRINTING.  547 

the  construction  and  operation  of  which  may  be  had  from  Fig.  121.  A 
is  a  cylindrical  "  bowl  "  or  drum,  covered  with  several  thicknesses  of 
felt  cloth,  c;  around  this  drum,  and  passing  over  a  smaller  one,  U,  is  an 
endless  band,  d  (full  width  of  the  machine)  ;  over  this  band,  and  acting 
as  a  guide  to  the  fabric  to  be  printed,  is  another  band,  e,  which  serves 
to  keep  d  clean,  being,  in  fact,  a  piece  of  cloth  yet  to  be  bleached  and 
printed;  the  piece  being  printed  is  indicated  by  /.  The  means  for 
applying  the  color  are  shown  in  the  figure  below  the  large  drum, — viz., 
the  printing  rollers  or  engraved  cylinders  ht,  7i2,  h3,  which  are  fed  with 
color  through  coming  in  contact  with  the  wooden  rollers  %,  n2,  ns, 
which  dip  in  the  color  contained  in  the  troughs  fct,  &2,  fc3.  Pressing 
against  each  of  the  rollers,  h,  is  shown  a  small  strip  of  metal,  r,  tech- 
nically termed  the  "  doctor,"  the  purpose  of  which  is  to  remove  the 
excess  of  color  from  the  face  of  the  printing-rollers  before  they  come 
in  contact  with  the  cloth.  These  ' '  doctors  ' '  are  best  made  of  bronze 
or  gun-metal,  or  some  of  the  newer  aluminum-copper  alloys, — capable 
of  better  resisting  weak  acid.  Before  the  cloth  is  printed  upon  it  passes 
over  a  "lint  doctor,"  the  office  of  which  is  to  remove  any  loose  hair  or 
fibres  from  the  cloth.  Printing-machines  are  built  wTith  any  number  of 
color  boxes  and  rollers  up  to  twelve  or  fourteen,  each  being  for  a  sepa- 
rate color.  Sansone  mentions  one  for  use  with  twenty  colors.  Great 
nicety  is  required  in  adjusting  the  machines  in  working  to  have  no  over- 
lapping of  colors  or  mordants, — perfect  "  registration  "  being  sought. 

For  drying  the  printed  goods  revolving  cylinders,  or  "  cans  "  of 
large  diameter,  are  used,  or  the  goods  are  passed  over  heated  plates,  in 
no  case  allowing  the  printed  face  to  come  in  contact  with  any  part  of  the 
apparatus.  Steaming  follows  to  fix  the  colors,  the  apparatus  being  a 
steamer,  as  shown  on  p.  540,  or  one  constructed  of  brick  and  iron,  act- 
ing  continuously,  thereby  turning  out  much  more  work  than  the  former. 
The  dyeing-  and  washing-machines  are  similar  to  those  already  described. 

Mordants,  Resists,  Discharge,  etc. — All  the  various  substances  used 
in  printing  must  be  applied  in  the  form  of  pastes,  the  consistency  of 
which  must  be  such  that  whenever  applied  they  will  not  run  or  spread, 
which  impairs  the  sharpness  of  outline  of  the  printed  pattern.  For 
the  purpose  the  color-mixer  has  recourse  to  the  starches  and  gums,  the 
most  important  of  which  are  corn  or  wheat  starch,  and  flour,  usually 
made  up  into  ten  per  cent,  pastes.  The  gums  include  gum  arabic,  dex- 
trine (British  gum),  and  tragacanth.  The  first  is  used  in  several  degrees 
of  consistency,  from  a  fifty  to  a  one  hundred  and  fifty  per  cent,  solution, 
dextrine  the  same,  and  the  last  in  a  ten  per  cent,  paste.  The  propor- 
tions are  by  no  means  uniform,  but  they  represent  the  average  strengths 
used  in  the  color  house.  Blood  albumen  is  considerably  used,  large 
quantities  being  manufactured  cheaply  in  Chicago  and  other  Western 
localities.  The  mordants  used  embrace  the  acetates  of  alumina  of  vari- 
ous strengths,  basic  sulphate,  and  others  of  less  importance.  The  ace- 
tates and  nitrates  of  iron  are  the  most  prominent  salts  of  this  element, 
and  of  chromium  there  may  be  mentioned  the  acetates  and  nitrates; 
others,  including  salts  of  tin,  calcium,  manganese,  are  also  used.  Owing 


548  BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 

to  the  great  number  of  recipes  published  for  preparing  mordants,  and 
of  the  difficulty  in  selecting  those  which  may  be  called  representative, 
only  a  few  will  be  given  of  the  more  important. 

Acetate  of  Alumina,  or  "  Red  Liquor  "  (Crookes). — 

Water     45  gallons.  45  gallons. 

Alum     100  pounds.  200  pounds. 

Acetate   of   lead    100         "  200         " 

Soda    crystals    10         "  10 

Or  the  same  result  can  be  had  by  substituting  acetate  of  calcium  for 
the  lead  salt.  In  either  case  the  alumina  salt  is  dissolved  in  about  half 
the  quantity  of  water,  and  the  acetate  in  the  remainder,  when  the  two 
solutions  are  mixed  and  allowed  to  settle,  the  precipitated  lime  or  lead 
sulphate  being  removed.  The  addition  of  soda  is  to  neutralize  any  free 
acetic  acid. 

Acetate  of  Iron,  or  "  Black  Iron  Liquor,"  can  be  obtained  either  by 
double  decomposition  as  above,  or  by  dissolving  scrap-iron  or  precipi- 
tated oxide  of  iron  in  crude  acid.  In  the  former  method  sulphate  of 
iron  and  acetate  of  lead  are  used  as  follows :  Water,  forty  pounds,  sul- 
phate of  iron,  twenty-four  pounds,  acetate  of  lead,  twenty-four  pounds. 
Dissolve  each  separately,  mix,  and  filter.  The  oxide  of  iron  above  men- 
tioned is  obtained  by  precipitating  a  solution  of  copperas  with  am- 
monia or  soda,  filtering  and  washing,  and  dissolving  the  moist  precipi- 
tate in  ordinary  acetic  acid  to  make  a  twenty-five  per  cent,  solution.  In 
the  event  of  using  soda,  much  longer  washing  is  required. 

Nitrate  of  Iron  is  made  as  above ;  copperas  and  nitrate  of  lead  being 
used  for  the  decompositions  in  equal  proportions.  Nitrates  made  by 
direct  solution  are  obtained  by  several  methods,  the  best  being  nitric 
acid  nearly  saturated  with  scrap-iron  and  diluted  to  about  80°  Tw. 
Some  of  the  so-called  nitrates  of  iron  are  mixtures  of  sulphate  and 
nitrate  of  iron  and  some  are  composed  entirely  of  sulphate  of  iron,  while 
others  are  waste  liquors,  such  as  are  obtained  by  dissolving  iron  out  of 
"  tin  scrap  "  by  means  of  sulphuric  acid.  Others  may  contain  hydro- 
chloric acid,  with  or  without  the  addition  of  copperas.  Chromium  Ace- 
tate is  similarly  prepared  with  chrome  alum  and  lead  acetate,  or  by 
precipitating  chrome  alum  with  an  alkali,  and  dissolving  the  washed 
precipitate  in  acetic  acid,  or  in  nitric  acid  if  the  nitrate  is  wanted.  This 
latter  mordant  can  be  made  by  using  lead  nitrate  and  chrome  alum. 

The  tin  mordants  are  used  to  brighten  the  color  with  madder  and 
cochineal  dyeing.  The  first  is  Stannous  Chloride,  SnCL  -f-  2H2O.  It 
is  made  by  dissolving  tin  in  hydrochloric  acid  and  evaporating  the  solu- 
tion. It  is  used  somewhat  in  wool-dyeing,  but  more  largely  in  calico- 
printing.  Stannic  chloride,  SnCl4,  is  also  used,  and  its  combination  with 
sal  ammoniac  known  as  "Pink  Salt,"  and  Sodium  Stannate,  Na2Sn03, 
known  as  "  Preparing  Salt." 

The  principal  styles  of  printing  tissues  are  given  in  the  following 
scheme.,  condensed  from  a  tabular  view  given  in  Sansone's  excellent 
work  on  "  Cotton-Printing." 


TEXTILE  PRINTING.  549 

PRINTED  (DIRECT)  COLORS. 

1.  Steam  or  Extract  Styles. 

(a)  Coal-tar  Colors. 

Alizarin,  Basic  Aniline  Colors,  Acid  Colors,  and  Neutral 

Azo  Colors. 

(6)  Dyewood  Extracts  (natural  organic  coloring  matters). 
Logwood,  Quercitron  Bark,  Sapan  and  other  Red  Woods, 

Catechu,   Annatto,    Cochineal. 
(c)  Steam  Mineral  Colors. 

2.  Pigment  Styles   (fixed  by  albumen). 

3.  Oxidation  Colors. 

4.  Direct  Indigo-printing  (alkaline  styles). 
DYED  COLORS. 

5.  Alizarin  Dyed  Styles. 

6.  Turkey-red  Styles. 

7.  Indigo  Styles. 

8.  Manganese  Bronze  Styles. 

1.  Steam  Styles. — Here  the  colors  and  proper  mordants  are  mixed, 
and  applied  to  the  fabric  in  one  operation,  followed  by  air  drying  and 
steaming,  or  by  immediate  steaming,  drying,  and  again  steaming,  the 
object  in  each  case  being  to  fix  and  develop  the  colors.  Several  condi- 
tions are  to  be  noted  in  this  style,  chiefly  the  humidity  of  the  steam, 
temperature,  pressure,  and  the  duration  of  the  steaming,  in  order  that 
the  same  shades  may  be  again  obtained  with  the  same  colors.  Before 
being  printed  the  cloth  is  passed  through  a  solution  of  stannate  of  soda, 
also  called  "  preparing  salt,"  and  then  through  sulphuric  acid  (1.005 
to  1.015  specific  gravity),  washed,  and  dried.  The  colors  best  suited 
are  the  basic, — that  is,  those  which  form  insoluble  lakes  with  tannin  in 
combination  with  a  metal,  and  the  general  method  of  applying  the  same 
is  given  in  the  following  extract  from  Sansone  ("  Printing  "),  p.  208: 
"  A  color  is  formed  consisting  of  thickening,  the  solution  of  coloring 
matter,  and  acetic  acid.  The  acetic  acid  is  added  in  the  preparation  of 
the  color  in  order  to  prevent  the  tannic  acid  from  combining  with  the 
dyestuff;  in  other  words,  the  acetic  acid  keeps  both  the  coloring  matter 
and  the  tannin  in  solution  in  the  thickened  color,  and  prevents  their 
combining  with  each  other;  but  when  the  color  is  printed  and  the  cloth 
is  dried  and  steamed,  the  acetic  acid  is  expelled,  and  the  coloring  mat- 
ter and  the  tannin  then  go  into  combination  to  form  the  insoluble  col- 
ored lake.  This  lake,  however,  not  being  sufficiently  fast  to  stand  by 
itself,  a  metallic  mordant  is  necessary  to  give  additional  fastness  to  the 
colors;  for  this  reason  the  cloth,  after  printing,  dyeing,  and  steaming, 
is  passed  into  a  solution  containing  tartar  emetic."  The  antimony  of 
which  at  once  unites  with  the  "  tannate  "  of  the  color  already  on  the 
fabric,  thereby  producing  a  more  insoluble  body.  The  steaming  opera- 
tion must  be  conducted  with  such  a  volume  of  steam  that  the  acetic  acid 
volatilized  can  be  carried  away,  or  else  the  colors  may  be  injured.  Of 
the  colors  employed  may  be  mentioned  the  Fuchsines,  Methyl  Violets  and 
Greens,  Bismarck  Brown,  Naphthylene  Blue,  etc. 


550  BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 

Alizarin,  without  exception,  is  the  most  important  coloring  matter 
used  in  cotton-printing,  for  which  purpose  the  goods  are  previously 
treated  with  alizarin  oil  and  dried.  With  alizarin  in  printing,  as  in  dye- 
ing, the  color  obtained  depends  upon  the  selection  of  the  mordant,  which 
can,  however,  be  a  mixture;  for  reds,  alumina,  with  or  without  tin; 
purples,  iron;  browns,  with  either  ferricyanide  of  potassium  or  acetate 
of  iron,  and  acetate  of  alumina,  or  with  chromium  mordants.  When 
the  fabrics  have  been  printed  they  are  steamed  for  one  or  two  hours, 
and  passed  through  a  heated  chalk-bath,  washed,  and  soaped.  The 
following  indicate  the  methods  of  preparing  several  colors: 

Red.      (Standard.) 

Alizarin  paste  (fifteen  per  cent.) 6       pounds. 

Starch   paste 2       gallons. 

Acetate  of  alumina  (11°  Be.)    1^  pints. 

Acetate    of   lime    (15°    Be. ) 1       pint. 

Nitrate  of  alumina    ( 13°    Be.)     %     " 

Purple.     ( Standard. ) 

Alizarin 2  pounds. 

Starch   paste    1  gallon. 

Acetate  of  iron   ( 13°  B6.) 1  quart. 

Acetate  of  lime  (13°  Be\) 1  pint. 

Acetic  acid    1 

Brown.     ( Standard. ) 

Alizarin   ( fifteen  per  cent. )    4  pounds. 

Starch  paste 1  gallon. 

Nitro-acetate  of  chromium   (25°  Be".)    3  pounds. 

Acetate  of  lime  (13°  B6.) %  pound. 

Since  the  introduction  of  the  alizarin  greens  and  violets,  their  use  in 
connection  with  chromium  in  cotton-printing  has  been  most  rapid. 

Dye-woods,  with  the  exception  of  logwood,  have  been  nearly  super- 
seded by  the  tar  colors.  The  method  of  applying  the  color  is  nearly  the 
same  as  for  other  steam  colors, — viz.,  print,  dry  in  the  air,  steam,  and 
wash,  and  is  made  up  with  chromium  as  the  mordant,  and  an  oxidizing 
agent,  with  or  without  the  presence  of  another  coloring  matter  to  modify 
the  shade. 

The  following  recipes  illustrate  the  color  as  made  for  blacks: 


Steam  Logwood  Black. 
Water    

(  Sansone.  ) 
1 

gallon. 

Acetic  acid   (6°  TV  )                           ... 

1 

H 

Logwood  extract   (  30°  Tw.  )    

1 

« 

Quercitron  bark  extract   (  30°  Tw.  ) 

2 

pounds. 

Starch        

5 

U 

Dextrine        

.\  .  .    2.5 

U 

Olive   oil    

5 

pound. 

75 

Boil,    stir    until    cold,    then    add 
Acetate  of  chromium   (20°  Tw.  ~\    . 

.    1 

gallon. 

TEXTILE  PRINTING.  551 

Steam  Logwood  Black.     (Sansone.) 

Starch 6     pounds. 

Flour 6 

Acetic  acid  (6°  Tw. ) 2.5  gallons. 

Logwood  extract   (20°  Tw.) 3.5       " 

Acetate  of  iron   ( 15°  Tw.)    3.5       " 

Olive  oil    1.5  pounds. 

Of.  the  other  natural  coloring  matters  there  may  be  mentioned  Cochi- 
neal, applied  with  tin  or  alumina;  Sapan,  in  the  same  manner,  and 
Quercitron  Bark,  with  alumina  or  chromium.  Catechu,  most  used  for 
browns,  may  be  applied  with  acetate  of  chromium  or  with  logwood  and 
fuchsine. 

The  Mineral  Colors  are  to  some  extent  made  use  of,  their  application 
depending  upon  the  principle  of  double  decomposition  upon  its  fibre 
when  subjected  to  steaming.  The  following  examples  will  make  the 
principle  clear:  Yellows  are  obtained  by  the  decomposition  of  nitrate 
of  lead  and  a  soluble  chromate,  the  insoluble  chromate  of  lead  ("  chrome 
yellow  ")  being  formed.  For  Blues,  both  prussiates  of  potash  are  used. 
Brown  is  obtained  by  means  of  chloride  of  manganese  and  bichromate 
of  potash. 

2.  Pigment  Styles. — For  this  style  effects  are  produced  by  means  of 
insoluble  color  lakes  and  the  mineral  colors,  which  are  fixed  upon  the 
cloth  by  steaming,  the  action  of  which  coagulates  the  albumen  with 
which  the  colors  are  invariably  mixed  for  printing.     The  colors  are  gen- 
erally supplied  to  the  color-mixer  in  a  dry  condition,  and  include  Ultra- 
marine of  various  qualities,  Vermilion  (sulphide  of  mercury) ,  the  Chro- 
mates   of   Lead   and  Barium,   Cadmium   Yellow    (cadmium   sulphide), 
Chrome  Green  (oxide  of  chromium),  the  Ochres,  yellow  and  red,  and 
Lamp-black.     A  familiar  example  of  this  style  is  seen  in  cheap  flags  and 
decorative  muslins. 

3.  Oxidation  Colors. — The  most  important  of  this  class  is  Aniline 
Black,  and  will  be  briefly  outlined  as  follows :  Aniline  oil  is  made  into  a 
paste  with  a  chlorate   (soda  generally)    and  a  metallic  salt,  with  the 
proper  amount  of  starch  paste.     This    is    printed    upon    the    fabric, 
"  aged  "  for  forty-eight  hours,  or  passed  through  a  "  steam  ager," 
then  passed  through  a  warm  bath  of  bichromate  of  potash,  washed  well, 
and  finally  worked  through  a  soap-bath.     The  metallic  salt  mentioned 
acts  as  a  carrier  of  oxygen,  and  for  the  purpose  vanadate  of  ammonium, 
sulphide  of  copper,  bichromate  of  potash,  etc.,  are  used.     For  the  prep- 
aration of  the  color  paste  the  following  methods  are  given: 

1.  Water    '. •. 1  gallon. 

Aniline  salt   2  pounds. 

Aniline  oil    2       " 

Starch    2       " 

Dextrine y2  pound. 


552  BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 

The  paste  is  made  first  with  the  starch  and  dextrine,  then  the  aniline  is 
added. 

2.  Chlorate  of  soda   (8°  B6.)    1  gallon. 

Starch    2  pounds. 

Dextrine     */2  pound. 

Chloride  of  ammonium    %       " 

These  are  made  separately,  but  when  wanted  are  mixed,  and  two  pounds 
of  sulphide  of  copper  paste  are  added,  and  the  whole  well  mixed  and 
strained.  (Crookes.) 

The  use  of  vanadium  is  shown  by  the  following  method  (Sansone, 
"Printing,"  p.  275): 

Water    1       gallon. 

Starch    1%  pounds. 

Dextrine    %  pound. 

Boil,  cool  down  to  120°  F.,  then  add 

Aniline  oil    1  %  pounds. 

previously  neutralized  with 

Hydrochloric  acid  (32°  Tw.) \yz  pounds. 

Stir  until  cold,  then  add  a  cold  solution  of 

Chlorate  of  soda %  pound. 

Boiling  water   1  " 

Before  printing  add  further 

Vanadium    solution     %       " 

Print,  dry  not  too  hard,  age  two  days,  then  pass  through  two  per  cent,  solution  of 
bichromate  of  potash  at  160°  F.,  wash  and  soap. 

The  vanadium  solution  is  made  with  vanadate  of  ammonia,  hydro- 
chloric acid,  glycerine,  and  water,  and  contains  about  .15  gramme  per 
litre. 

Other  colors  are  produced  by  oxidation, — namely,  Brown  (with 
phenylendiamine,  Sansone),  by  simply  printing  with  a  chlorate,  dry- 
ing, and  steaming,  Yellow,  Grays,  Olives,  Blues,  etc.  To  obtain  white 
patterns  on  goods  printed  with  aniline  black,  a  "  resist  "  or  "  reserve  " 
is  first  applied  of  the  desired  pattern,  consisting  of  white  arsenic  as  the 
base,  with  caustic  soda,  and  the  proper  thickening.  For  discharging 
the  aniline  black  after  it  is  printed,  permanganate  of  potash  is  used; 
the  goods  are  afterwards  passed  through  a  solution  of  oxalic  acid. 

4.  Indigo-printing. — Indigo  is  printed  upon  cotton  fabics  in  two 
ways,  one  of  which  is  known  as  the  ' '  Glucose, ' '  and  the  other  the  ' '  Re- 
duced Indigo  "  Process.  The  former  is  carried  out  as  follows:  Indigo 
is  finely  ground,  and  made  into  a  paste  with  water,  to  which  is  added 
caustic  soda;  this  is  now  kept  in  a  closed  vessel  in  order  to  prevent  as 
much  as  possible  the  absorption  of  carbonic  oxide  from  the  atmosphere. 
"When  used  in  printing,  it  is  thickened  with  dextrine  and  starch;  the 
following  table  (from  Sansone,  "  Cotton-Printing,"  p.  284)  showing 
the  proportions  used  for  several  shades:  • 


TEXTILE  PRINTING. 


553 


Light  calcined  starch  3  parts.  3      parts.  3  parts. 

Indian  corn  starch iy2      "  iy2      "  iya       " 

Water    3%       "  3%       "  3%       " 

Caustic  soda  lye   (70°  Tvv.)  .    16  "  28          "  40          " 

Indigo   paste    30          "  18  "  6          " 

The  cloth,  before  being  printed  upon,  is  worked  through  a  twenty- 
five  per  cent,  solution  of  glucose  and  dried.  After  printing,  the  cloth 
must  be  again  dried  and  passed  through  an  atmosphere  of  wet  steam, 
in  an  apparatus  shown  in  Fig.  122,  to  effect  the  reduction  of  the  indigo, 
which  now  takes  place.  The  cloth  is  now  washed  in  water,  being  re- 
peatedly, during  the  washing,  exposed  to  the  air,  when  the  reduced 
indigo  is  oxidized  and  its  real  color  appears.  The  reason  for  rapidly 
steaming  is  to  act  upon  the  caustic  alkali  while  it  is  still  in  that  state, 

FIG.  122. 


as  if  it  should  become  carbonated  through  delay  little  reduction  will 
take  place.  This  method  is  employed  in  printing  indigo  upon  alizarin- 
dyed  goods  and  in  other  combinations  with  resists,  etc. 

The  ' '  Reduced  Indigo  Process  ' '  is  based  upon  the  fact  that  indigo, 
when  finely  ground  and  mixed  with  lime  and  thiosulphate  of  soda  in 
suitable  thickening  agents,  is  reduced ;  if,  with  this  reduced  indigo  paste, 
patterns  are  printed  upon  cotton  fabrics,  and  then  exposed  to  the  air, 
the  indigo  is  oxidized  with  a  regeneration  of  the  blue  color.  The  pieces 
are  then  washed  and  dried. 

Instead  of  using  indigo  in  printing,  one  of  the  newer  colors,  7m- 
medial  Blue,  is  now  very  extensively  used  and  printed  with  suitable 
mordants  directly  upon  the  goods. 

5.  Dyed  Alizarin. — This  process  differs  from  all  those  previously 
mentioned  in  that  the  colors  are  produced  by  first  printing  upon  the 
fabric  the  thickened  mordants  suited  to  alizarin,  ageing,  during  which 
the  mordants  so  printed  are  decomposed  and  more  firmly  fixed  upon 
the  cloth,  dunging,  an  operation  which  removes  the  thickening  no  longer 


554  BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 

needed,  followed  by  a  washing,  and  then  dyeing  with  alizarin,  and, 
finally,  brightening.  The  mordants  used  for  Reds  are  generally  made 
with  acetate  of  alumina,  thickened  with  starch  or  flour,  and  dextrine, 
while  by  the  addition  of  tin  to  such  a  mixture  blue  shades  will  be  ob- 
tained. For  Purples  or  Violets,  acetate  of  iron  is  used  diluted  with 
paste,  if  used  strong,  blacks  can  be  produced.  Browns  are  obtained 
with  catechu  and  copper  acetates.  Mixtures  of  the  acetates  of  iron  and 
alumina  yield  varying  shades  of  Chocolate.  Following  the  printing 
operation,  the  fabric  is  allowed  to  dry,  when  it  is  aged  by  being  caused 
to  pass  through  the  continuous  steamer;  here  the  acetates  are  decom- 
posed, basic  salts  remaining  fixed  upon  the  cloth.  Formerly  the  opera- 
tion wras  conducted  in  large  rooms,  and  often  required  a  week  to  finish ; 
now  long  chambers  provided  with  a  series  of  rollers,  and  with  requisite 
means  for  steam  control,  are  used;  it  must  be  remarked  that  colors  ob- 
tained upon  cloth  rapidly  aged  do  not  compare  in  fastness  with  those  ob- 
tained upon  cloth  slowly  aged.  Dunging  is  merely  a  transmission  of 
the  aged  cloth  through  solutions  of  phosphate,  arseniate,  or  silicate  of 
soda,  these  chemicals  having  displaced  the  somewhat  offensive  cow-dung 
in  the  operations  of  precipitating  the  mordant  upon  the  fibre,  and  also 
tc  remove  the  thickening  and  excess  of  mordant,  after  which  the  cloth 
is  well  washed  and  then  dyed.  The  dye-bath  is  made  up  with  alizarin, 
alizarin  oil,  tannin,  etc.,  in  a  similar  manner  to  that  described  under 
Dyeing  (p.  539),  after  which  the  cloth  is  washed,  worked  in  alizarin  oil, 
dried,  and  steamed,  then  washed  and  soaped.  In  case  reds  have  been 
dyed,  and  it  is  desirable  to  reduce  their  tone,  "  cutting  "  is  resorted  to 
after  the  soaping,  by  means  of  a  solution  of  stannic  chloride. 

Resists  are  substances  printed  upon  the  fabric  which  will  prevent 
the  fixation  of  color  at  those  places,  and  are  of  two  kinds,  chemical  and 
mechanical ;  the  former  are  composed  chiefly  of  citric  acid,  while  the  latter 
are  made  up  of  some  inert  substances,  such  as  pipe-clay,  beeswax,  etc. 
Thus  a  resist  (or  reserve)  of  citrate  of  soda  (lime- juice  and  soda  lye)  when 
applied  to  the  cloth  prevents  the  fixation  of  the  oxides  of  iron  or  alumina 
on  the  fibre,  and  therefore  when  the  cloth  is  afterwards  dunged  and 
dyed  in  the  alizarin  bath  the  reserved  spots  remain  white,  while  the 
colors  will  be  formed  where  the  mordant  has  been  fixed.  In  this  way 
not  only  reds  and  pinks  can  be  reserved,  but  purples,  chocolates,  and 
blacks  also.  Discharges  are  substances  printed  upon  goods  the  whole 
of  which  had  been  mordanted,  the  object  being  to  remove  the  mordant 
from  places  where  whites  are  to  appear,  consequently  when  the  piece 
is  dyed  only  where  the  mordant  is  intact  will  the  cloth  be  colored ;  these 
discharges  are  made  principally  with  citric,  tartaric,  or  acetic  acid. 
This  acid-containing  discharge  having  been  printed  on,  the  goods  are 
then  taken  through  a  solution  of  bleaching-powder  (chloride  of  lime). 
The  result  is  that  where  the  acids  have  been  printed  on  chlorine  gas  is 
liberated,  which  destroys  the  dye-color,  leaving  in  the  simplest  cases  a 
white  design  upon  a  colored  ground. 

6.  Turkey-red  Styles. — This  process  is  simply  printing  upon  cloth 
which  has  previously  been  dyed  Turkey-red  (see  p.  539)  by  means  of 


TEXTILE  PRINTING.  555 

discharges,  which  may  or  may  not  be  made  so  as  to  yield  colored  pat- 
terns. The  base  is  citric  or  tartaric  acid,  thickened  with  a  suitable 
paste,  and  if  for  colors,  containing  a  salt  of  lead  if  for  a  yellow  dis- 
charge, or  ferro-prussiate  of  potash  for  a  blue  discharge,  or  iron  and 
logwood  for  a  black  discharge.  After  printing  on  the  discharges,  the 
goods  are  passed  through  a  bath  of  bleaching-powder,  well  washed,  and 
then,  if  lead  has  been  printed  on,  passed  through  a  bath  of  bichromate 
of  potash,  when  chrome  yellow  will  be  produced.  If  the  prussiate  of 
potash  has  been  printed,  a  blue  color  will  be  developed.  Green  is  ob- 
tained by  mixing  both  discharges  first. 

7.  Indigo  Styles  are  similar  to  the  above;  resists  are  printed  on  the 
cloth,  which  is  then  dyed  in  the  vat  in  the  ordinary  manner,  when,  upon 
a  removal  of  the  resist  by  suitable  means,  white  patterns  are  had  upon 
a  blue  ground.     By  the  system  of  discharges  various  colors  may  be  put 
on  by  means  of  lead  and  other  metallic  salts.     Vermilion  is  applied 
directly  with  albumen.     For  a  discharge  which  has  to  be  afterwards  dyed 
red  with  alizarin,  bromide  of  manganese  and  an  aluminum  salt  are  used. 

8.  Manganese  Bronze  Style,  or  Bistre  Style. — This  process  has  for 
its  object  the  production  of  hydrated  peroxide  of  manganese  upon  the 
fibre,  and  the  subsequent  printing  of  colors  by  means  of  discharges. 
The  goods  are  worked  in  a  solution  of  manganous  chloride,  dried,  and 
worked  in  soda  lye,  washed  and  passed  through  a  solution  of  chloride 
of  lime  until  a  brown  color  is  produced.     Wash,  dry,  and  the  goods  are 
ready  for  printing.     A  discharge  for  white  is  made  with  muriate  of  tin 
(120°  Tw.)  ;  for  blue,  yellow  prussiate  of  potash  with  an  organic  acid; 
for  yellow,  a  lead  salt,  developed  with  bichromate  of  potash.     Green  and 
black  as  in  the  previous  style. 

Woollen-  and  Silk-printing. — Wool,  either  as  yarn  or  fabric,  is  gen- 
erally printed  with  the  tar  colors,  and  according  to  the  steam  style  pre- 
viously described.  The  goods  are  dried  after  printing,  steamed  for  one 
hour,  and  well  washed.  Silk  is  printed  in  the  same  style  after  being 
prepared  by  suitable  agents,  such  as  tin  with  or  without  an  acid.  Pre- 
vious to  being  printed  both  silk  and  wool  must  be  entirely  free  from 
grease.  Silk  warps  for  ribbon  and  veiling  are  often  printed  by  hand 
blocks,  and  with  aniline  colors  dissolved  and  thickened  with  Irish  moss. 
After  printing,  the  warps  are  simply  air  dried — being  neither  washed 
nor  steamed.  Such  colors  are  not  fast,  but  they  are  much  used  for  so- 
called  "  Dresden  "  and  "  Persian  effects." 


556 


BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 


The  following  table  from  Rupe's  "  Cliemie  cler  Naturliehen  FarbstofFe" 
(Braunschweig,  1900)  shows  the  artificial  dye-colors  which  have  replaced 
or  are  in  practical  use  competing  with  the  natural  dyestuifs  named  : 


NATURAL  DYESTUFFS. 


Is  displaced  for  cotton. 


Is  displaced  for  wool  and  silk. 


QUERCITRON 


PERSIAN  BERRIES  . 


WELD 


FUSTIC 


LOGWOOD 


BRAZIL-WOOD 


COCHINEAL 


ARCHIL 


ANNATTO 


Mainly  by  substantive  dye-colors : 
Diamine  fast  yellow  B  A  (C.),  Chlora- 
mine  yellow  (C.),  Chrysophenine  (C.), 
Auramine  (H.  G.),  Diamine  yellow 
(H.),  Chrysamine  (H.),  Thioflavine 
(G.).  For  printing  along  with  log- 
wood it  is  still  used  as  before. 

Are  still  much  used  in  cotton-print- 
ing and  in  connection  with  tin 
salts.  For  direct  printing  compete : 
Auramine,  Thioflamne  T  (C.),  the 
latter  exclusively  for  discharges; 
in  addition.  Chrysophenine  (H.), 
Chloramine  yellow  (H.),  Oriol  (G.). 
Important  are  also  the  yellow  sal- 
icylic acid  azo  colors,  such  as 
Alizarin  yellow  (H.),  etc. 

Is  hardly  ever  used  for  cotton. 


Almost  entirely  displaced  by  the  sub- 
stantive yellow  dyes,  as  with  quer- 
citron. In  addition,  Sun  yellow  (G. ), 
Diphenyl  fast  yellow  (G.),  Cresolin 
yellow  (G.),  also  by  Alizarin  yellow 
and  its  homologues  ( H. ) .  For  print- 
ing in  connection  with  logwood  it 
is  still  unreplaced. 

In  cotton  dyeing  (for  black)  is  about 
given  up.  For  better  goods  is  re- 
placed by  Aniline  black,  Diaminogen 
black  (C.),  for  cheaper  goods  by 
the  direct  dyeing  and  diazotizable 
blacks:  Diamine  black  (C.) ,  Oxydia- 
mine  black  (C. ),  Columbia  black  (C.). 
Direct  deep  black  (C.),  also  by  Vidal 
black,  Iminedial  black  (G.  H.),  and 
similar  sulphated  products. 


For  cotton  scarcely  used  now,  being 
replaced  by  the  substantive  dye- 
ing reds :  Diamine  fast  red  F  (C.), 
Congorubine  (C.),  Diamine  bordeaux 
(C.),  Benzopurpurine  (G.  H.),  Dia- 
mine red  (H.),  also  by  Fuchsine 
(G.  H.),  Hessian  purple  (G.),  Safra- 
mine,  (H.),  Paranitraniline  red  (H.), 
Alizarin  red  (H.). 


For  cotton  is  replaced  by  the  dif- 
ferent artificial  orange  colors,  as 
Chrysophenine  (H. ),  Chrysamine 
(H.),  Mikado  yellow  and  orange  (H.). 


Is  not  much  used  now,  the  dif- 
ferent mordant  coloring  yellows 
haying  taken  its  place.  In  ad- 
dition, Naphthol  yellow  S  (H.), 
Tartrazine,  Quinoline  yellow  (H.). 


Little  used  for  wool,  For  silk  re- 
placed by  Tartrazine,  Fulling  yel- 
(ow  (C.),  Naphthol  yellow  S  (H.). 


Is  little  used  for  wool,  but,  on  the 
other  hand,  largely  for  silk.  Is 
replaced  by  Naphthol  yellow  S, 
Hist  yellow  (C.),  Tartrazine,  Failing 
yellow  (C.),  Citronine  (G.),  Jasmine 
(G.),  Azo  yellow  (G.),  Alizarin  yel- 
low (H.). 

Is  still  much  used  in  wool-dyeing, 
although  strongly  pushed  by  the 
different  mordant-attracting  yel- 
lows: Anthracene  yellow  C  (C.  G.), 
Chrome  yellow  (C.  G.),  Mordant  yel- 
low (C.  G.),  Fulling  yellow  (C.), 
Azo  yellow  (H.),  Fast  yellow  (H.), 
Alizarin  yellow  (H.). 

With  wool  the  case  is  the  same  as 
with  cotton.  It  is  still  used  for 
dyeing,  but  is  losing  ground  rap- 
idly. The  substitutes  are  :  Naph- 
thol and  Kaphthylamine  black  (C. 
G.  H.),  Brilliant  black  (C.  G.),  Dia- 
mond black  (C.  G.  H.),  Wool  black 
(C. ),  Alizarin  black  (G.  H.),  An- 
thracene black  (C.  G.),  Azo  acid 
black  (H.),  Chromotrope  S  (H.). 
For  silk,  still  used  enormously 
and  with  no  substitute. 

Also  for  wool  and  silk  almost  en- 
tirely replaced  by  Cloth  red  (C. 
Wool  red  (C.),  Acid  fuchsine  (G. 
Fast  red  ( H. ) ,  Arch  U  substitute  ( G. , . 
Ponceau  (H.),  Apollo  red  (G.),  Ro- 
cellin  (G.);  in  the  fulling  industry 
by  Alizarin  red  (C.  H.),  Diamine 
fast  red  (C.),  Chromotrope  (H.). 

Is  still  used  somewhat  for  wool  and 
silk,  but  is  being  displaced  by 
vivid  acid  wool  colors,  such  as 
Azoeosin  (G.),  Chromazon  red  (G.), 
Palatine  scarlet  (H.  C.),  Brilliant 
crocein  (H.),  Brilliant  cochineal 
(C.),  and  the  different  Ponceaux, 
etc. 

Has  practically  been  entirely  dis- 
placed for  wool  and  silk  by  the 
readily  levelling  red  acid  wool 
dyes:  'Acid  fuchsine  (C.),  Azocar- 
mine  (C.  G.  H.),  Archil  substitute 
CO.  G.  PI.),  Azoftichsine  (C.  G.  H.K 
Lana/uchsine  (C.),  Azorubine  (C.), 
Azo  acid  fuchsine  (H.),  Rosindu- 
line  (G.),  Apollo  red  (G.),  Chromo- 
trope (H.). 


BIBLIOGRAPHY. 


557 


NATURAL  DYESTUFFS. 


Is  displaced  for  cotton. 


19  displaced  for  wool  and  silk. 


SAFFLOWER 


BERBERINE 
CATECHU.  . 


Was  first  replaced  for  cotton  by  the 
Eosines,  Phlpxine  (C.  G.) ;  later 
these  were  displaced  by  Rhodamine 
(C.  G.),  Erica  (C.),  JDiamine  rose 
(C.),  Geranine  (C.),  Safranine  (H.), 
etc. 


INDIGO 


Still  used  for  cotton,  although  a 
whole  series  of  excellent  substan- 
tive dyes  have  appeared.  Espe- 
cially have  the  Diamine  colors, 
Benzo  and  Congo  colors  with  sup- 
plementary treatment  with  chrome 
and  copper,  recently  competed  suc- 
cessfully (C.),  and  Chrysoidine  (H.), 
Vesuvine  ( H. ) ,  etc.  For  calico-print- 
ing, catechu  is  still  very  largely 
used,  although  the  different  Aliza- 
rin colors  are  seeking  to  displace 
it  in  part  (C.). 

Despite  the  many  seriously  com- 
peting products  is  still  much  used 
for  cotton.  These  competing  prod- 
ucts are :  Synthetic  indigo,  Indoin 
(C.  G.  H.),  Naphthindon  (C.),  Fast 
cotton  blue  (C.),  Methylene  blue 
(C.  H.),  Jndamine  blue  (H.),  Janus 
blue  (H.),  and  the  direct  coloring 
and  diazotizable  blues  of  the  Dia- 
mine,  Diphenyl,  and  Benzo  color 
groups.  [Diamine  blue  and  related 
colors  (H.),  Diaminogen  blue  (C. 
H.).]  A  new  product,  Immedial 
blue  (C.  H.),  belonging  to  the  sul- 
phated  colors,  which  has  recently 
appeared,  seems  to  be  among  the 
most  important  substitutes.  In 
calico-printing,  Indigo  has  been  in 
part  replaced  by  the  Synthetic  in- 
digo preparations  and  by  the  dif- 
ferent basic  blues,  including  Nitroso 
blue,  Alizarin  blue,  etc.  (C.). 


Is  not  used  for  wool,  but  still  some- 
what for  silk.  Substitutes  are  the 
same  as  those  mentioned  for  Weld. 

Still  used  for  silk  in  combination 
with  logwood  in  large  amount 
without  any  competing  products 
(C.).  For  weighting  of  silk. 


On  wool,  is  replaced  on  the  one 
hand  by  Alizarin  blue  (C.  G.  H.), 
Synthetic  indigo,  Alizarin  cyanine 
(C.  G.  H.),  Anthracene  blue  (G.  H.), 
Chromotrope  F  B  (H.),  Gattamine 
blue  (G.),  Gattocyanine  (G.),  and 
on  the  other  hand  by  Sulpho- 
cyanine  (C.)  and  Lanacyl  blue. 
However,  the  application  of  In- 
digo to  wool  still  holds  out  rela- 
tively well. 


The  communications  upon  which  this  table  is  based  were  from  the  firms  of  Leopold  Casella  &  Co., 
of  Frankfurt-am-Main  (C.),  Joh.  Rud.  Geigy  &  Co.,  of  Basel  (G.),  and  Farbwerke,  vormals  Meister, 
Lucius  and  Briining,  of  Hochst  (H.). 


Bibliography. 


1875, 
1876. 


1877, 
1878, 


Manual  of  Dyeing  and  Dyeing  Receipts,  Napier,  London. 
Dyeing  and  Calico-Printing,  Grace  C'alvert,  Manchester. 
Cantor  Lectures  on  Wool-Dyeing,  G.  Jarmain,  London. 
-Traite  de  la  Teintures  des  Soies,  M.  Moyret,  Lyons. 
Die  chemische  Bearbeitung  der  Schafwolle,  V.  Joclet,  Vienna. 
-Le  Conditionnement  de  la  Soie,  Jules  Persoz,  Paris. 
Handbuch  der  Bleichkunst,  Victor  Joclet,  Vienna. 
Calico-Printing,  Bleaching,  and  Dyeing,  C.  O'Neill,  London. 
The  American  Dyer,  by  Gibson,  Boston. 

1879. — Die  Woll-  und  Seidendruckerei,  Victor  JoclSt,  Vienna. 
Handbuch  der  Seidenfiirberei,  Philip  David. 
Bleicherei,  Farberei  und  Appretur,  C.  Romen,  Berlin. 
A  System  of  Chemistry  applied  to  Dyeing,  Jas.  Napier,  Philadelphia. 
The  Art  of  Dyeing,  Cleaning,  and  Scouring,  Thos.  Love,  2d  ed.,  Philadelphia. 
Die  Technologic  der  Gespinnstfasern,  2  Bde.,  H.  Grothe,  Berlin. 
Die  Wascherei,  Bleicherei  und  Farberei  von  Wollengarnen,  R.  Sachse,  Leipzig. 
Manual  of  Colors  and  Dye-wares,  J.  W.  Slater,  London. 
Dyeing  and  Tissue-Printing,  W.  Crookes,  London. 


1880 
1881 
1882 


558  BLEACHING,  DYEING,  AND  TEXTILE  PRINTING. 

1883. — La  Teinture  du  Coton,  A.  Renard,  Paris. 

TraitS  pratique  du  Degraissage,  etc.,  A.  Gillet,  Paris. 
1884 — Bleaching,  Dyeing,  and  Calico-Printing,  J.  Gardner,  London. 

Bleaching,  Dyeing,  and  Calico-Printing,  F.  J.  Bird,  London. 

Die  Bleicherei,  Druckerei,  Farberei,  etc.,  der  baumwollenen  Gewebe,  G.  Stein, 

Braunschweig. 

1885 — Die  praktische  Anwendung  der   Theerfarben   in  der  Industrie,   E.   J.   Hodl, 
Vienna. 

The  Dyeing  of  Textile  Fabrics,  J.  J.  Hummel,  London. 

Die  Beizen,  ihre  Darstellung,  etc.,  H.  Wolff,  Vienna. 

Die  Gesammte  Indigo-Kupenblau  Farberei,  E.  Rudolf. 
1886. — Praktische  Anleitung  zur  Bleicherei,  etc.,  von  Jutestoffen,  R.  Ernst. 

Die  Appretur-Mittel  und  ihre  Anwendung,  F.  Polleyn,  Vienna. 
1887. — Teinture  et  Apprets  des  Tissus  de'  Coton,  L.  Lefebre,  Paris. 

The  Printing  of  Cotton  Fabrics,  A.  Sansone,  Manchester. 

L'Art  la  Soie,  N.  Rondot,  2  vols.,  Paris. 
1888. — Dyeing,  A.  Sansone,  2  vols.,  Manchester. 

Des  Couleurs  et  de  leurs  Applications,  2me  ed.,  E.  Chevreul,  Paris. 
1889. — Handbuch  der  Farberei,  Dr.  A.  Ganswindt,  Weimar. 

Les  Matieres  Colorantes  et  la  Chemie  de  la  Teinture,  C.  L.  Tassart,  Paris. 

The  Guide  for  Piece-Dyeing,  F.  W.  Reisig,  New  York. 
1890. — L'Industrie  de  la  Teinture,  C.  L.  Tassart,  Paris. 

Trait6  de  Teinture  sur  Laine,  P.  F.  Levaux,  Liege. 

Ueber  das  Fiirbe  der  Strangseide,  W.  Vollbrecht,  Berlin. 

Bleicherei,  Wiischerei,  Carbonisation,  J.  Herzfeld,  Berlin. 

Farberei  der  Baumwolle  mit  Substantiven  Farbstoffe,   Soxhlet,   Stuttgart. 

Anilin   Fiirberei   und  Druckerei   auf   Baumwolle,   Soxhlet,   Stuttgart. 
1891. — Traite"  de  la  Teinture  et  de  I'lmpression,  lere  partie,  J.  Depierre,  Miilhausen. 

Chemische  Technologic  der  Gespinnstfasern,  O.  Witt,  Berlin. 
1892 — Silk-Dyeing,  Printing,  and  Finishing,  J.  H.  Hurst,  London. 
1893. — Traite  pratique  de  la  Teinture  et  de  I'lmpression,  2me  ed.,  M.  de  Vinant, 

Paris. 
1894. — Manual  of.  Dyeing,  Knecht,  Rawson,  and  Lowenthal,  3  vols.,  London. 

Teinture  et  Impression,  Prud'homme,  Paris. 
1895. — Bleichen  und  Fiirben  der  Seide  und  Halbseide,  C.  H.  Steinbeck,  Berlin. 

Les  Industries  Textiles,  Guignet,  Dommer,  et  Grandmougin,  Paris. 
1896. — Bleaching  and  Calico-Printing,  Duerr  and  Turnbull,  Philadelphia. 
1897. — La  pratique  Teinturier,  J.  Garcon,  3  tomes,  Paris. 

Printing  of  Textile  Fabrics,  C.  F.  Rothwell,  London. 

Wool-Dyeing,  Part  i,  W.  M.  Gardner,  Philadelphia. 

Recent  Progress  in  the  Industries  of  Dyeing  and  Calico-Printing,  A.  Sansone, 

3  vols.,  Manchester. 

1898. — Technologic  der  Gespinnstfaser,  v.  Georgievics,  Wien. 
1903. — The  Principles  of  Dyeing,  G.  S.  Fraps,  The  Macmillan  Co.,  New  York. 
1905. — Hypochlorite  und  Electrische  Bleiche,  Abel. 
1906. — The  Chemistry  and  Physics  of  Dyeing,  W.  P.  Dreaper,  Philadelphia. 

The  Chemistry  and  Practice  of  Sizing,  etc.,  P.  Bean  and  F.  Scarrsbrick,  Man- 
chester. 

Theorie  und  Praxis  der  garnfarberei  mit  Azoentwicklern,  Franz  Erban,  Berlin. 

Blanchissage  et  1'appret  du  ligne,  L.  Verefel. 

1907. — Farbereichemische  Untersuchungen,  Dr.  Paul  Hermann,  2te  Auf.,  Berlin. 
1908. — The  Methods  of  Textile  Chemistry,  F.  Dannerth,  London. 

Die  Technologic  der  appretur,  A.  Ganswindt,  Wien. 


BIBLIOGRAPHY.  559 

1909. — The  Dyeing  and  Bleaching  of  Textile  Fabrics,  F.  A.  Owen,  J.  Wiley  &  Son, 

New  York. 
Laboratory  Manual  of  Dyeing  and  Textile  Chemistry,  J.  Merritt  Matthews, 

John  Wiley  &  Son,  New  York. 
Farbereichemisches    Practicum,    etc.,    Richard   Mohlau    und   Hans    Bucherer, 

Viet  &  Co.,  Leipzig. 

Handbvich  der  Farben-lehre,  E.  Berger,  2te  Auf.,  Leipzig. 
Modern  Bleaching  Agents  and  Detergents,  Max  Bottler.     Translated  by  Chas. 

Salter,  Scott  &  Greenwood,  London. 

A  Manual  of  Dyeing,  etc.,  by  E.  Knecht,  2  vols.,  2d  ed.,  C.  Griffin,  London. 
1910. — Das  Farben  und  Bleichen  von  Baumwolle,  Seide,  etc.,  J.  Herzfeld,  3te  Auf. 
1911. — The  Principles  of  Bleaching  and  Finishing  of  Cotton,   S.  R.   Frohman  and 

E.  L.  Thorp,  London. 
Anleitung  zur  qualitativen  Appretur  und  Schlichte- Analyse,  Wilhelm  Massot, 

Berlin. 


APPENDIX. 


I.    The  Metric  System. 

THE  French  metric  system  is  based  upon  the  idea  of  employing,  as 
the  unit  of  all  measures,  whether  of  length,  capacity,  or  weight,  a  uni- 
form unchangeable  standard,  adopted  from  nature,  the  multiples  and 
subdivisions  of  which  should  follow  in  decimal  progression.  To  obtain 
such  a  standard,  the  length  of  one-fourth  part  of  the  terrestrial  meridian, 
extending  from  the  equator  to  the  pole,  was  ascertained.  The  ten- 
millionth  part  of  this  arc  was  chosen  as  the  unit  of  measures  of  length, 
and  was  denominated  meter.  The  cube  of  the  tenth  part  of  the  meter 
was  taken  as  the  unit  of  measures  of  capacity,  and  denominated  liter. 
The  weight  of  distilled  water,  at  its  greatest  density,  which  this  cube  is 
capable  of  containing,  was  called  kilogram,  of  which  the  thousandth  part 
was  adopted  as  the  unit  of  weight,  under  the  name  of  gram.  The  multi- 
ples of  these  measures,  proceeding  in  a  decimal  progression,  are  distin- 
guished by  employing  the  prefixes,  deca,  hecto,  kilo,  and  myria,  taken 
from  the  Greek  numerals ;  and  the  subdivisions,  following  the  same  order, 
by  deci,  centi,  milli,  from  the  Latin  numerals.  Since  the  introduction 
of  this  system  it  has  been  adopted  by  the  principal  nations  of  Europe, 
excepting  Great  Britain,  and  in  many  of  them  its  use  is  compulsory. 
It  is  in  general  use  in  France,  Germany,  Austria,  Italy,  Spain,  Norway, 
Sweden,  Netherlands,  Switzerland,  Greece  and  British  India.  It  was 
legalized  in  Great  Britain  in  1864,  and  in  the  United  States  by  an  act 
of  Congress  in  1866. 

The  meter,  or  unit  of  length,  at  32°,  =  39.370432  inches. 

The  liter,  or  unit  of  capacity,  =  33.816  fluidounces.     U.  S. 

The  gram,  or  unit  of  weight,  =   15.43234874  Troy  grains. 

Upon  this  basis  the  following  tables  have  been  constructed: 

MEASURES   OF   LENGTH. 


English  inches. 

Millimeter  (mm.)  =  .03937 

Centimeter  (cm.)  =  .39370 

Decimeter  (dm.)  3.93704 

Meter  (m.)  =  39.37043 


English  inches. 

Decameter  (Dm.)          =  393.70432 

Hectometer  (Hm.)        =  3937.04320 

Kilometer  (Km.)  39370.43200 

Myriameter  (Mm.)        =        393704.32000 
36  561 


562 


APPENDIX. 


MEASURES   OF   CAPACITY. 


Milliliter  (ml.) 
Centiliter  (el.) 
Deciliter  (dl.) 
Liter  (1.) 


Milligram  (mg.) 
Centigram  (eg.) 
Decigram  (dg.) 
Gram  (gm.) 


English  cubic  inches. 

.061028 

.610280 

6.102800 

61.028000 


Decaliter  (Dl.) 
Hectoliter  (HI.) 
Kiloliter  (Kl.) 
Myrialiter  (Ml.) 


MEASURES   OP   WEIGHT. 


Troy  grains. 

.0154 

.1543 

1.5432 

15.4323 


Decagram  (Dg.) 
Hectogram  (Hg.) 
Kilogram  (Kg.) 
Myriagram  (Mg.) 


English  cubic  inches. 

610.280000 

6102.800000 

61028.000000 

610280.000000 


Troy  grains. 

154.3234 

1543.2348 

15432.3487 

154323.4874 


EQUIVALENT   WEIGHTS   AND    MEASURES. 


1  kilometer  =  1093.61    yards 

or       0.621  statute  mile 
1  square  meter  =  10.764  square  feet 
1  cubic  meter  =  35.3  cubic  feet 
1  liter  =  1  quart  and  J  gill  U.  S.  measure 

or  1  pint  and  3  gills  Imperial  measure 
1  cubic  centimeter  =   .061      cubic  inch 
or  0.03381  fluidounce 
1  hectoliter  =  26.4    U.  S.  gallons 

or  22.01  Imperial  gallons 
1  kilogram  =  2.204  Ibs.  avd. 

or  2  Ibs.  3  ozs.  4|  drams 
1  inch  =  25.4  millimeters 


1  foot  =  0.3048  meter 

1  yard  =  0.9144  meter 

1  square  foot  =  0.0929  square  meter 

1  cubic  inch  =  16.3872  cubic  centimeters 

1  cubic  foot  =  0.02832  cubic  meter 

1  pound  avd.  =  453.5925  grams 

1  ounce  avd.  =  28.3495  grams 

1  grain  =  0.0648  gram 

1  U.  S.  gallon  =  3.78543  liters 

1  Imperial  gallon  =  4.54346  liters 

1  U.  S.  quart  =  0.94636  liter 

1  fluidounce  =  28.396  cubic  centimeters 


I.    Tables  for  Determination  of  Temperature. 

RELATIONS  BETWEEN  THERMOMETERS. 

In  Fahrenheit's  thermometer,  the  freezing-point  of  water  is  placed 
at  32°,  and  the  boiling-point  at  212°,  and  the  number  of  intervening 
degrees  is  180. 

The  Centigrade  or  Celsius's  thermometer,  which  is  now  recognized  in 
the  U  S.  Pharmacopeia  and  has  been  adopted  generally  by  scientists, 
marks  the  freezing-point  zero,  and  the  boiling-point  100°. 

From  the  above  statement,  it  is  evident  that  180  degrees  of  Fahren- 
heit are  equal  to  100°  of  the  Centigrade,  or  one  degree  of  the  first  is 
equal  to  f  of  a  degree  of  the  second.  It  is  easy,  therefore,  to  convert 
the 'degrees  of  one  into  the  equivalent  number  of  degrees  of  the  other; 
but  in  ascertaining  the  corresponding  points  upon  the  different  scales,  it 
is  necessary  to  take  into  consideration  their  different  modes  of  gradua- 
tion. Thus,  as  the  zero  of  Fahrenheit  is  32°  below  the  point  at  which 
that  of  the  Centigrade  is  placed,  this  number  must  be  taken  into  account 
in  the  calculation. 

1.  If  any  degree  on  the  Centigrade  scale,  either  above  or  below  zero, 
be  multiplied  by  1.8,  the  result  will,  in  either  case,  be  the  number  of 
degrees  above  or  below  32°,  or  the  freezing-point  of  Fahrenheit. 

2.  The  number  of  degrees  between  any  point  of  Fahrenheit's  scale 
and  32°,  if  divided  by  1.8,  will  give  the  corresponding  point  on  the 
Centigrade. 


APPENDIX. 


563 


THERMOMETKIC  EQUIVALENTS. 

ACCORDING  TO  THE  CENTIGRADE  AND  FAHRENHEIT  SCALES. 


0» 

P.° 

C.° 

P.° 

C° 

F.° 

C.° 

F.° 

C.° 

F°. 

—39.4 

—39 

—17.2 

1 

5 

41 

27.2 

81 

49.4 

121 

—39 

—38.2 

—17 

1.4 

5.5 

42 

27.7 

82 

50 

122 

—38.8 

—38 

—16.6 

2 

6 

42.8 

28 

82.4 

50.5 

123 

—38.3 

—37 

—16.1 

3 

6.1 

43 

28.3 

83 

51 

123.8 

-38 

—36.4 

—16 

3.2 

6.6 

44 

28.8 

84 

51.1 

124 

—37.7 

—36 

—15.5 

4 

7 

44.6 

29 

84.2 

51.6 

125 

—37.2 

—35 

—15 

6 

7.2 

45 

29.4 

85 

52 

125.6 

—37 

—34.6 

—14.4 

6 

7.7 

46 

30 

86 

52.2 

126 

—36.6 

—34 

—14 

6.8 

8 

46.4 

30.5 

87 

52.7 

127 

—36.1 

—33 

—13.8 

7 

8.3 

47 

31 

87.8 

53 

127.4 

—36 

-32.8 

—13.3 

8 

8.8 

48 

81.1 

88 

53.3 

128 

—35.5 

—32 

—13 

8.6 

9. 

48.2 

31.6 

89 

53.8 

129 

—35 

—31 

—12.7 

9 

9.4 

49 

32 

89.6 

54 

129.2 

—34.4 

-30 

—12.2 

10 

10 

50 

32.2 

90 

54.4 

130 

—34 

—29.2 

—12 

10.4 

10.5 

51 

32.7 

91 

55 

131 

—33.8 

—29 

—11.6 

11 

11 

61.8 

33 

91.4 

55.5 

132 

—33.3 

—28 

—11.1 

12 

11.1 

62 

33.3 

92 

56 

182.8 

—33 

—27.4 

—11 

12.2 

11.6 

53  • 

33.8 

93 

56.1 

133 

—32.7 

—27 

—10.5 

13 

12 

53.6 

34 

93.2 

56.6 

134 

—32.2 

—26 

—10 

14 

12.2 

54 

34.4 

94 

57 

134.6 

—32 

—25.6 

—9.4 

15 

12.7 

55 

35 

95 

57.2 

135 

—31.6 

—25 

—9 

15.8 

13 

55.4 

35.5 

96 

57.7 

136 

—31.1 

—24 

—8.8 

16 

13.3 

56 

36 

96.8 

68 

136.4 

—31 

—23.8 

—8.3 

17 

13.8 

57 

36.1 

97 

58.3 

137 

—30.5 

—23 

—8 

17.6 

14 

57.2 

36.6 

98 

58.8 

138 

—30 

—22 

—7.7 

18 

14.4 

58 

37 

98.6 

59 

138.2 

—29.4 

—21 

—7.2 

19 

15 

69 

37.2 

99 

59.4 

139 

—29 

—20.2 

1 

19.4 

15.5 

60 

37.7 

100 

60 

140 

—28.8 

—20 

—6.6 

20 

16 

60.8 

38 

100.4 

60.5 

141 

—28.3 

—19 

—6.1 

21 

16.1 

61 

38.3 

101 

61 

141.8 

—28 

—18.4 

—6 

21.2 

16.6 

62 

38.8 

102 

61.1 

142 

—27.7 

—18 

—5.5 

22 

17 

62.6 

39 

102.2 

61.6 

143 

—27.2 

—17 

—5 

23 

17.2 

63 

39.4 

103 

62 

143.6 

—27 

—16.6 

—4.4 

24 

17.7 

64 

40 

104 

62.2 

144 

—26.6 

—16 

—4 

24.8 

18 

64.4 

40.5 

105 

62.7 

145 

—26.1 

—15 

—3.8 

25 

18.3 

6.5 

41 

105.8 

63 

145.4 

—26 

—14.8 

—3.3 

26 

18.8 

66 

41.1 

106 

63.3 

146 

—25.5 

—14 

—3 

26.6 

19 

66.2 

41.6 

107 

63.8 

147 

—25 

—13 

—2.7 

27 

19.4 

67 

42 

107.6 

64 

147.2 

—24.4 

—12 

—2.2 

28 

20 

68 

42.2 

108 

64.4 

148 

—24 

—11.2 

—2 

28.4 

20.5 

69 

42.7 

109 

66 

149 

—23.8 

—11 

—1.6 

29 

21 

69.8 

43 

109.4 

65.5 

150 

—23.3 

—10- 

-1.1 

30 

21.1 

70 

43.3 

110' 

66 

150.8 

—23 

—9.4 

—1 

30.2 

21.6 

71 

43.8 

111 

66.1 

151 

—22.7 

—9 

—0.5 

31 

22 

71.6 

44 

111.2 

66.6 

152 

—22.2 

—8 

0 

32 

22.2 

72 

44.4 

112 

67 

152.6 

—22 

—7.6 

0.5 

33 

22.7 

73 

45 

113 

67.2 

153 

—21.6 

—7 

1 

33.8 

23 

73.4 

45.5 

114 

67.7 

154 

—21.1 

—6 

1.1 

34 

23.3 

74 

46 

114.8 

68 

154.4 

—21 

—5.8 

1.6 

35 

23.8 

75 

46.1 

115 

68.3 

155 

—20.5 

—5  • 

2 

35.6 

24 

75.2 

46.6 

116 

68.8 

156 

—20 

—4 

2.2 

36 

24.4 

76 

47 

116.6 

69 

156.2 

—19.4 

—3 

2.7 

37 

25 

77 

47.2 

117 

69.4 

157 

—19 

—2.2 

3 

37.4 

25.5 

78 

47.7 

118 

70 

158 

—18.8 

2 

3.3 

38 

26 

78.8 

48 

118.4 

70.5 

159 

—18.3 

—1 

3.8 

39 

26.1 

79 

48.3 

119 

71 

159.8 

—18 

—0.4 

4. 

39.2 

26.6 

80 

48.8 

120 

71.1 

160 

—17.7 

0 

4.4 

40 

27 

80.6 

49 

120.2 

71.6 

161 

564 


APPENDIX. 
Thermometric  Equivalents. — Continued. 


c.° 

F.°- 

C.° 

F.° 

C.° 

F.° 

C.° 

F.° 

C.° 

F.° 

72 

161.6 

95.5 

204 

118.8 

246 

142.2 

288 

166 

830.8 

72.2 

162 

96 

204.8 

119 

246.2 

142.7 

289 

166.1 

331 

72.7 

163 

96.1 

205 

119.4 

247 

143 

289.4 

166.6 

332 

73 

163.4 

96.6 

206 

120 

248 

143.3 

290 

167 

332.6 

73.3 

164 

97 

206.6 

120.5 

249 

143.8 

291 

167.2 

333 

73.8 

165 

97.2 

207 

121 

249.8 

144 

291.2 

167.7 

334 

74 

165.2 

97.7 

208 

121.1 

250 

144.4 

292 

168 

334.4 

74.4 

166 

98 

208.4 

121.6 

251 

145 

293 

168.3 

335 

75 

167 

98.3 

209 

122 

251.6 

145.5 

294 

168.8 

336 

75.5 

168 

98.8 

210 

122.2 

252 

146 

294.8 

169 

336.2 

76 

108.8 

99 

210.2 

122.7 

253 

146.1 

295 

169.4 

337 

76.1 

169 

99.4 

211 

123 

253.4 

146.6 

296 

170 

338 

76.6 

170 

100 

212 

123.3 

254 

147 

296.6 

170.5 

339 

77 

170.6 

100.5 

213 

123.8 

255 

147.2 

297 

171 

339.8 

77.2 

171 

101 

213.8 

124 

255.2 

147.7 

298 

171.1 

340 

77.7 

172 

101.1 

214 

124.4 

256 

148 

298.4 

171-6 

341 

78 

172.4 

101.6 

215 

125 

257 

148.3 

299 

172 

341.6 

78.3 

173 

102 

215.6 

125.5 

258 

148.8 

300 

172.2 

342 

78.8 

174 

102.2 

216 

126 

258.8 

149 

300.2 

172.7 

343 

79 

174.2 

102.7 

217 

126.1 

259 

149.4 

301 

173 

343.4 

79.4 

175 

103 

217.4 

126.6 

260 

150 

302 

173.3 

344 

80 

176 

103.3 

218 

127 

260.6 

150.5 

303 

173.8 

345 

80.5 

177 

103.8 

219 

127.2 

261 

151 

303.8 

174 

345.2 

81 

177.8 

104 

219.2 

127.7 

262 

151.1 

304 

174.4 

346 

81.1 

178 

104.4 

220 

128 

262.4 

151.6 

305 

175 

347 

81.6 

179 

105 

221 

T28.3 

263 

152 

305.8 

175.5 

348 

82 

179.6 

105.5 

222 

128.8 

204 

152.2 

306 

176 

348.8 

82.2 

180 

106 

222.8 

129 

264.2 

152.7 

307 

176.1 

349 

82.7 

181 

106.1 

223 

129.4 

205 

153 

307.4 

176.6 

350 

83 

181.4 

106.6 

224 

130 

266 

153.3 

308 

177 

350.6 

83.3 

182 

107 

224.6 

130.5 

267 

153.8 

309 

177.2 

351 

83.8 

183 

107.2 

225 

131 

267.8 

154 

309.2 

177.7 

352 

84 

183.2 

107.7 

226 

131.1 

268 

154.4 

310 

178 

352.4 

84.4 

184 

108 

226.4 

131.6 

269 

155 

311 

178.3 

353 

85 

185 

108.3 

227 

132 

269.6 

155.5 

312 

178.8 

354 

85.5 

186 

108.8 

228 

132.2 

270 

156 

312.8 

179 

354.2 

86 

186.8 

109 

228.2 

132.7 

271 

156.1 

313 

179.4 

355 

86.1 

187 

109.4 

229 

133 

271.4 

156.6 

314 

180 

356 

86.6 

188 

110 

230 

133.3 

272 

157 

314.6 

180.5 

357 

87 

188.6 

110.5 

231 

133.8 

273 

157.2 

315 

181 

357.8 

87.2 

189 

111 

231.8 

134 

273.2 

157.7 

316 

181.1 

358 

87.7 

190 

111.1 

232 

134.4 

274 

158 

316.4 

181.6 

359 

88 

190.4 

111.6 

233 

135 

275 

158.3 

317 

182 

359.6 

88.3 

191 

112 

233.6 

135.5 

276 

158.8 

318 

182.2 

360 

88.8 

192 

112.2 

234 

136 

276.8 

159 

818.2 

182.7 

361 

89 

192.2 

112.7 

235 

136.1 

277 

159.4 

819 

183 

361.4 

89.4 

193 

113 

235.4 

136.6 

278 

160 

320 

183.3 

362 

90 

194 

113.3 

236 

137 

278.6 

160.5 

321 

183.8 

363 

90.5 

195 

113.8 

237 

137.2 

279 

161 

821.8 

184 

363.2 

91 

195.8 

114 

237.2 

137.7 

280 

161.1 

822 

184.4 

364 

91.1 

196 

114.4 

238 

138 

280.4 

1<51.6 

823 

185 

365 

91.6 

197 

115 

239 

138.3 

281 

162 

323.6 

185.5 

306 

92 

197.6 

115.5 

240 

138.8 

282 

162.2 

324 

186 

366.8 

92.2 

198 

116 

240.8 

139 

282.2 

162.7 

825 

186.1 

367 

92.7 

199 

116.1 

241 

139.4 

283 

163 

325.4 

186.6 

368 

93 

199.4 

116.6 

242 

140 

284 

163.3 

826 

187 

368.6 

93.3 

200 

117 

242.6 

140.5 

285 

163.8 

327 

187.2 

369 

93.8 

201 

117.2 

243 

141 

285.8 

164 

327.2 

187.7 

370 

94 

201.2 

117.7 

244 

141.1 

286 

164.4 

828 

188 

370.4 

94.4 

202 

118 

244.4 

141.6 

287 

165 

329 

188.3 

371 

95 

203 

118.3 

245 

142 

287.6 

165.5 

330 

188.8 

372 

APPENDIX. 
Themnometric  Equivalents. — Continued. 


565 


c.° 

F.° 

C.° 

F.° 

C.° 

F.° 

C.° 

F.° 

C.° 

F.° 

189 

372.2 

211.6 

413 

233.8 

453 

256.1 

493 

278.3 

533 

189.4 

373 

212 

413.6 

234 

453.2 

256.6 

494 

278.8 

534 

190 

374 

212.2 

414 

234.4 

454 

257 

494.6 

279 

534.2 

190.5 

375 

212.7 

415 

235 

455 

257.2 

495 

279.4 

535 

191 

375.8 

213 

415.4 

235.5 

456 

257.7 

496 

280 

536 

191.1 

376 

213.3 

416 

236 

456.8 

258 

496.4 

280.5 

537 

191.6 

377 

213.8 

417 

236.1 

457 

258.3 

497 

281 

537.8 

192 

377.6 

214 

417.2 

236.6 

458 

258.8 

498 

281.1 

538 

192.2 

378 

214.4 

418 

237 

458.6 

259 

498.2 

281.6 

539 

192.7 

379 

215 

419 

237.2 

459 

259.4 

499 

282 

539.6 

193 

379.4 

215.5 

420 

237.7 

460 

260 

500 

282.2 

540 

193.3 

380 

216 

420.8 

238 

460.4 

260.5 

501 

282.7 

541 

193.8 

381 

216.1 

421 

238.3 

461 

261 

501.8 

283 

541.4 

194 

381.2 

216.6 

422 

238.8 

462 

261.1 

502 

283.3 

542 

194.4 

382 

217 

4226 

239 

462.2 

261.6 

503 

283.8 

543 

195 

383 

217.2 

423 

239.4 

463 

262 

503.6 

284 

5432 

195.5 

384 

217.7 

424 

240 

464 

262.2 

504 

284.4 

544 

196 

384.8 

218 

424.4 

240.5 

465 

262.7 

505 

285 

545 

1961 

385 

218.3 

425 

241 

465.8 

263 

505.4 

285.5 

546 

196.6 

386 

218.8 

426 

241.1 

466 

263.3 

506 

286 

546.8 

197 

386.6 

219 

426.2 

241.6 

467 

263.8 

507 

286.1 

547 

197.2 

387 

219.4 

427 

242 

467.6 

264 

507.2 

286.6 

548 

197.7 

388 

220 

428 

242.2 

468 

264.4 

508 

287 

548.6 

198 

388.4 

220.5 

429 

242.7 

469 

265 

509 

287.2 

549 

198.3 

389 

221 

429.8 

243 

469.4 

265.5 

510 

287.7 

550 

198.8 

390 

221.1 

430 

243.3 

470 

266 

510.8 

288 

550.4 

199 

390.2 

221.6 

431 

243.8 

471- 

266.1 

511 

288.3 

551 

199.4 

391 

222 

431.6 

244 

47.  2 

266.6 

512 

288.8 

552 

200 

392 

222.2 

432 

2444 

472 

267 

512.6 

289 

552.2 

200.5 

393 

222.7 

433 

245 

473 

267.2 

613 

289.4 

553 

201 

393.8 

223 

433.4 

245.5 

474 

267.7 

514 

290 

654 

201.1 

394 

223.3 

434 

246 

474.8 

268 

514.4 

290.5 

555 

201.6 

395 

223.8 

435 

246.1 

475 

268.3 

515 

291 

555.8 

202 

395.6 

224 

435.2 

246.6 

476 

268.8 

516 

291.1 

556 

202.2 

396 

224.4 

436 

247 

476.6 

269 

516.2 

291.6 

557 

202.7 

397 

225 

437 

247.2 

477 

269.4 

517 

292 

657.6 

203 

397.4 

225.5 

438 

247.7 

478 

270 

518 

292.2 

558 

203.3 

398 

226 

438.8 

248 

478.4 

270.5 

519 

292.7 

559 

203.8 

399 

226.1 

439 

248.3 

479 

271 

519.8 

293 

559.4 

204 

399.2 

226.6 

440 

248.8 

480 

271.1 

520 

293.3 

560 

204.4 

400 

227 

440.6 

249 

480.2 

271.6 

521 

293.8 

561 

205 

401 

227.2 

441 

249.4 

481 

272 

521.6 

294 

561.2 

205.5 

402 

227.7 

442 

250 

482 

272.2 

522 

294.4 

562 

206 

402.8 

228 

442.4 

250.5 

483 

272.7 

523 

295 

563 

206.1 

403 

2283 

443 

251 

483.8 

273 

523.4 

295.5 

564 

206.6 

404 

228.8 

444 

251.1 

484 

273.3 

524 

296 

564.8 

207 

404.6 

229 

444.2 

251.6 

485 

273.8 

625 

296.1 

565 

207.2 

405 

229.4 

445 

252 

485.6 

274 

525.2 

296.6 

566 

207.7 

406 

230 

446 

252.2 

486 

274.4 

526 

297 

566.6 

208 

406.4 

230.5 

447 

252.7 

487 

275 

627 

297.2 

567 

208.3 

407 

231  - 

447.8 

253 

487.4 

275.5 

528 

297.7 

568 

208.8 

408 

231.1 

448 

253.3 

488 

276 

528.8 

298 

568.4 

209 

408.2 

2316 

449 

253.8 

489 

276.1 

529 

298.3 

669 

209.4 

409 

232 

4496 

254 

489.2 

276.6 

530 

298.8 

570 

210 

410 

232.2 

450 

254.4 

490 

277 

530.6 

299 

570.2 

210.5 

411 

232.7 

451 

255 

491 

277.2 

531 

299.4 

571 

211 

411.8 

233 

451.4 

255.5 

492 

277.7 

532 

300 

572 

211.1 

412 

233.3 

452 

256 

492.8 

278 

532.4 

566 


APPENDIX. 


HI.    Specific  Gravity  Tables. 

1.  Baume's  Scale  for  Liquids  Lighter  than  Water. 

The   following  table  is  calculated   for  a  temperature  of   17.5°    C. 

140 

=  specific  gravity  and 


(63.5°  F.),  and  is  based  on  the  formulas 
140 


1Qn 
loU 


—  ^  -  - 
specific  gravity 


130  =  B.°. 


Degree 
Baum6. 

Specific 
gravity. 

Degree 
BaumtJ. 

Specific 
gravity. 

Degree 
Baum6. 

Specific 
gravity. 

Degree 
Baum6. 

Specific 
gravity. 

10 

1.0000 

33 

0.8588 

56 

0.7526 

79 

0.6698 

11 

0.9929 

34 

0.8536 

57 

0.7486 

80 

0.6666 

12 

0.9859 

35 

0.8484 

58 

0.7446 

81 

0.6635 

13 

0.9790 

36 

0.8433 

59 

0.7407 

82 

0.6604 

14 

0.9722 

37 

0.8383 

60 

0.7368 

83 

0.6573 

16 

0.9655 

38 

0.8333 

61 

0.7329 

84 

0.6542 

16 

0.9589 

39 

0.8284 

62 

0.7290 

85 

0.6511 

17 

0.9523 

40 

0.8235 

63 

0.7253 

86 

0.6482 

18 

0.9459 

41 

0.8187 

64 

0.7216 

87 

0.6452 

19 

0.9395 

42 

0.8139 

65 

0.7179 

88 

0.6422 

20 

0.9333 

43 

0.8092 

66 

0.7142 

89 

0.6393 

21 

0.9271 

44 

0.8045 

67 

0.7106 

90 

0.6363 

22 

0.9210 

45 

0.8000. 

68 

0.7070 

91 

0.6335 

23 

0.9150 

46 

0.7954 

69 

0.7035 

92 

06306 

24 

0.9090 

47 

0.7909 

70 

0.7000 

93 

0.6278 

25 

0.9032 

48 

0.7865 

71 

0.6965 

94 

0.6250 

26 

0.8974 

49 

0.7821 

72 

0.6931 

95 

0.6222 

27 

0.8917 

50 

0.7777 

73 

0.6896 

96 

0.6195 

28 

0.8860 

51 

0.7734 

74 

0.6863 

97 

0.6167 

29 

0.8805 

52 

0.7692 

75 

0.6829 

98 

0.6140 

30 

0.8750 

53 

0.7650 

76 

0.6796 

99 

0.6113 

31 

0.8695 

54 

0.7608 

77 

0.6763 

100 

0.6087 

32 

0.8641 

55 

0.7567 

78 

0.6731 

The  coefficient  of  expansion  of  petroleum  oils  for  increase  or  decrease 
of  1°  .0.  in  temperature  has  been  determined  for  both  Russian  and 
American  oils.  For  the  latter  the  following  figures  have  been  given 
(Iron  Age,  xxxviii,  No.  7)  : 

Specific  gravity  Coeflicient  of 

at  15°  C.  (59°  F.).  expansion  for  1°  C. 

UnderO.700 0.00090 

0.700  to  0.750      0.00085 

0.750  to  0.800      0.00080 

0.800  to  0.815      s 0.00070 

Over  0.815 0.00065 

As  stated  in  the  text  (p.  39),  it  is  customary  in  practice  to  take  as 
the  coefficient  of  expansion  0.004  for  every  10°  F.  (0.00072  for  1°  C.). 


APPENDIX. 


567 


2.  Comparison  of  Various  Baume  Hydrometers  for  Liquids  Heavier 
than  Water  with  Specific  Gravities.     (Lunge's  Technical 
Methods  of  Chemical  Analysis,  vol.  i,  p.  935.) 


Degrees. 

Rational 
Hydrometer 

.            144.3 

a==  — 

Baum6's 
Hydrometer 
according  to 
Gerlach's 
scale. 

Baume1 
American 
scale 

.            145 

I 

Rational 
Hydrometer 

d        U4'3 

Baum6's 
Hydrometer 
according  to 
Gerlach's 
scale. 

Baum6 
American 
scale 

145 

144.3  —  » 

'      145-n 

144.3—  n 

d      145-n 

1 

1.007 

1.0068 

1.005 

34 

1.308 

1.3015 

1.309 

2 

1.014 

1.0138 

1.011 

35 

1.320 

1.3131 

1.317 

3 

1.022 

1.0208 

1.023 

36 

1.332 

1.3250 

1.334 

4 

1.029 

1.0280 

1.029 

37 

1.345 

1.3370 

1.342 

5 

1.037 

1.0353 

1.036 

38 

1.357 

1.3494 

1.359 

6 

1.045 

1.0426 

1.043 

39 

1.370 

1.3619 

1.368 

7 

1.052 

1.0501 

1.050 

40 

1.383 

1.3746 

1.386 

8 

1.060 

1.0576 

1.057 

41 

1.397 

1.3876 

1.395 

9 

1.067 

1.0653 

1.064 

42 

1.410 

1.4009 

1.413 

10 

1.075 

1.0731 

1.071 

43 

1.424 

1.4134 

1.422 

11 

1.083 

1.0810 

1.086 

44 

1.438 

1.4281 

1.441 

12 

1.091 

1.0890 

1.093 

45 

1.453 

1.4421 

1.451 

13 

1.100 

1.0972 

1.100 

46 

1.468 

1.4564 

1.470 

14 

1.108 

1.1054 

1.107 

47 

1.483 

1.4710 

1.480 

15 

1.116 

1.1138 

1.114 

48 

1.498 

1.4860 

1.500 

16 

1.125 

1.1224 

1.122 

49 

1.514 

1.5012 

1.510 

17 

1.134 

1.1310 

1.136 

50 

1.530 

1.5167 

1.531 

18 

1.142 

1.1398 

1.143 

51 

1.540 

1.5325 

1.541 

19 

1.152 

1.1487 

1.150 

52 

1.563 

1.5487 

1.561 

20 

1.162 

1.1578 

1.158 

53 

1.580 

1.5652 

1.573 

21 

1.171 

1.1670 

1.172 

54 

1.597 

1.5820 

1.594 

22 

1.180 

1.1763 

1.179 

55 

1.615 

1.5993 

1.616 

23 

1.190 

1.1858 

1.186 

56 

1.634 

1.6169 

1.627 

24 

1.200 

1.1955 

1.201 

57 

1.652 

1.6349  . 

1.650 

25 

1.210 

1.2053 

1.208 

58 

1.671 

1.6533 

1.661 

26 

1.220 

1.2153 

1.216 

59 

1.691 

1.6721 

1.683 

27 

1.231 

1.2254 

1.231 

60 

1.711 

1.6914 

1.705 

28 

1.241 

1.2357 

1.238 

61 

1.732 

1.7111 

1.727 

29 

1.252 

1.2462 

1.254 

62 

1.753 

1.7313 

1.747 

30 

1.263 

1.2569 

1.262 

63 

1.774 

1.7520 

1.767 

31 

1.274 

1.2677 

1.269 

64 

1.796 

1.7731 

1.793 

32 

1.285 

1.2788 

1.285 

65 

1.819 

1.7948 

1.814 

33 

1.297 

1.2901 

1.293 

66 

1.842 

1.8171 

1.835 

What  is  known  as  the  "  Rational  "  Baume  scale  is  calculated  by  tak- 
ing water  at  the  temperature  chosen  at  0°  B.  and  sulphuric  acid  of  1.842 

144  3 

specific  gravity  at  66°  B.  and  using  the  formula  — -  =  d.     (See 

J.  4:4.o  —  n 

Lunge's  "  Sulphuric  Acid  and  Alkali,"  vol.  1,  p.  20.) 


568 


APPENDIX. 


3.  Twaddle's  Scale  for  Liquids  Heavier  than  Water. 


Degrees  ~] 
Twaddle.  | 

l£ 

3  > 

O>  at 

oo'Sb 

Degrees 
Twaddle. 

<£•& 

'S'> 

0  g 

£•& 

Degrees 
Twaddle. 

<S£ 
•3  > 

P.2 

MM 

Degrees 
Twaddle. 

g& 

'3  > 

2Lfi 

00  "> 

Degrees 
Twaddle. 

££ 

"3  > 

Q>  at 

&E 

oa  w> 

Degrees 
Twaddle. 

£* 

P 
£*> 

Degrees 
Twaddle. 

0  X 
tC  ;*~* 
'oV 

&! 

K  M 

0 

1.000 

29 

1.145 

58 

1.290 

87 

1.435 

116 

1.580 

145 

1.725 

173 

1.865 

1 

1.005 

30 

1.150 

59 

1.295 

88 

1.440 

117 

1.585 

146 

1.730 

174 

1.870 

2 

1.010 

31 

1.155 

60 

1.300 

89 

1.445 

118 

1.590 

147 

1.735 

175 

1.875 

3 

1.015 

32 

1.160 

61 

1.305 

90 

1.450 

119 

1.595 

148 

1.740 

176 

1.880 

4 

1.020 

33 

1.165 

62 

1.310 

91 

1.455 

120 

1.600 

149 

1.745 

177 

1.885 

5 

1.025 

34 

1.170 

63 

1.315 

92 

1.460 

121 

1.605 

150 

1.750 

178 

1.890 

6 

1.030 

35 

1.175 

64 

1.320 

93 

1.465 

122 

1.610 

151 

1.755 

179 

1.895 

7 

1.035 

36 

1.180 

65 

1.325 

94 

1.470 

123 

1.615 

152 

1.760 

180 

1.900 

8 

1.040 

37 

1.185 

66 

1.330 

95 

1.475 

124 

1.620 

153 

1.765 

181 

1.905 

9 

1.045 

38 

1.190 

67 

1.335 

96 

1.480 

125 

1  625 

154 

1.770 

182 

1.910 

10 

1.050 

39 

1.195 

68 

1.340 

97 

1.485 

T2G 

1.630 

155 

1.775 

183 

1.915 

11 

1.055 

40 

1.200 

69 

1.345 

98 

1.490 

127 

1.635 

156 

1.780 

184 

1.920 

12 

1.060 

41 

1.205 

70 

1.350 

99 

1.495 

128 

1.640 

157 

1.785 

185 

1.925 

13 

1.065 

42 

1.210 

71 

1.355 

100 

1.500 

129 

1.645 

158 

1.790 

186 

1.930 

14 

1.070 

43 

1.215 

72 

1.360 

101 

1.505 

130 

1.650 

159 

1.795 

187 

1.935 

15 

1.075 

44 

1.220 

73 

1.365 

102 

1.510 

131 

1.655 

160 

1.800 

188 

1.940 

16 

1.080 

45 

1.225 

74 

1.370 

103 

1.515 

132 

1.660 

161 

1.805 

189 

1.945 

17 

1.085 

46 

1.230 

75 

1.375 

104 

1.520 

133 

1.665 

162 

1.810 

190 

1.950 

18 

1.090 

47 

1.235  ! 

76 

1.380 

105 

1.525 

134 

1.670 

163 

1.815 

191 

1.955 

19 

.095 

48 

1.240 

77 

1.385 

106 

1.530 

135 

1.675 

164 

1.820 

192 

1.960 

20 

.100 

49 

1.245 

78 

1.390 

107 

1.535 

136 

1.680 

165 

1.825 

193 

1.965 

21 

.105 

50 

1.250 

79 

1.395 

108 

1.540 

137 

1.685 

166 

1.830 

194 

1.970 

22 

.110 

51 

1.255 

80 

1.400 

109 

1.545 

138 

1.690 

167 

1.835 

195 

1.975 

23 

.115 

52 

1.260 

81 

1.405 

110 

1.550 

139 

1.695 

168 

1.840 

196 

1.980 

24 

.120 

53 

1.265 

82 

1.410 

111 

1.555 

140 

1.700 

169 

1.845 

197 

1.985 

25 

.125 

54 

1.270 

83 

1.415 

112 

1.560 

141 

1.705 

170 

1.850 

198 

1.990 

26 

1.130 

55 

1.275 

84 

1.420 

113 

1.565 

142 

1.710 

171 

1.855 

199 

1.995 

27 

1.135 

56 

1.280 

85 

1.425 

114 

1.570 

143 

1.715 

172 

1.860 

200 

2.000 

28 

1.140 

57 

1.285 

86 

1.430 

115 

1.575 

144 

1.720 

The  uniform  division  of  the  Twaddle  scale  makes  the  degrees  very 
easily  convertible  into  specific  gravity  readings  It  is  only  necessary  to 
multiply  the  degree  as  read  off  by  five  and  add  this  to  1.000  in  order  to 
obtain  the  specific  gravity. 

Again,  as  the  gallon  of  distilled  water  at  ordinary  temperatures 
weighs  ten  pounds  avoirdupois,  it  is  possible  to  determine  the  weight  of  a 
gallon  of  an  acid  or  lye  by  the  aid  of  the  Twaddle  scale.  Thus,  if  an  acid 
shows  50°  Twaddle,  corresponding  to  the  specific  gravity  1.250,  it  weighs 
twelve  and  a  half  pounds  per  gallon.  Or,  as  a  liter  of  distilled  water 
weighs  one  thousand  grams,  a  liter  of  a  liquid  showing  20°  Twaddle 
will  weigh  eleven  hundred  grams. 


APPENDIX. 


569 


4.   Comparison  of  the  Twaddle  Scale  with  the  Rational  Baume  Scale. 


Twaddle. 

Baume. 

>l 

O*J 

*  > 
»8 

|a 

03 

Twaddle. 

Baume. 

1 

at 

O  oS 
O  (_ 
£460 
02 

Twaddle. 

Baume. 

o£ 

*•? 

Is 

&> 

00 

Twaddle. 

•<0 

i 

i 

1 

«£> 
2> 

t>  oj 

«  £ 
&M 

X 

0 

0 

1.000 

44 

26.0 

1.220 

88 

44.1 

1.440 

131 

57.1 

1.655 

1 

0.7 

1  .005 

45 

264 

1.225 

89 

44.4 

1.445 

132 

57.4 

1.660 

2 

1.4 

1.010 

46 

26.9 

1.230 

90 

44.8 

1.450 

133 

57.7 

1.665 

3 

2.1 

1.015 

47 

27.4 

1.235 

91 

45.1 

1.455 

134 

57.9 

1.670 

4 

2.7 

1.020 

48 

27.9 

1.240 

92 

45.4 

1.400 

135 

58.2 

1.675 

5 

3.4 

1.025 

49 

28.4 

1.245 

93 

45.8 

1.465 

136 

58.4 

1.680 

6 

4.1 

1.030 

50 

28.8 

1.250 

94 

46.1 

1.470 

137 

58.7 

1.685 

7 

4.7 

1.035 

51 

29.3 

1.255 

95 

46.4 

1.475 

138 

58.9 

1.690 

8 

5.4 

1.040 

52 

29.7 

1.260 

96 

46.8 

1.480 

139 

59.2 

1.695 

9 

6.0  1.045 

53 

30.2 

1.265 

97 

47.1 

1.485 

140 

59.5 

1.700 

10 

6.7 

1.050 

54 

30.6 

1.270 

98 

47.4 

1.490 

141   59.7 

1.705 

11 

7.4 

1.055 

55 

31.1 

1.275 

99 

47.8 

1.495 

142 

60.0 

1.710 

12 

8.0 

1.060 

56 

31.5 

1.280 

100 

48.1 

1.500 

143 

60.2 

1.715 

13 

8.7 

1.065 

67 

32.0 

1.285 

101 

48.4 

1.505 

144 

60.4 

1.720 

14 

9.4 

1.070 

58 

32.4 

1.290 

102 

48.7 

1.510 

145 

606 

1.725 

15 

10.0 

1.075 

59 

32.8 

1.295 

103 

49.0 

1.515 

146 

609 

1.730 

16 

10.6 

1.080 

60 

33.3 

1.300 

104 

49.4 

1.520 

147 

61.1 

1.735 

17 

11.2 

1.085 

61 

33.7 

1.305 

105 

49.7 

1.525 

148 

61.4 

1.740 

18 

11.9 

1.090 

62 

34.2 

1.310 

106 

50.0 

1.530 

149 

61.6 

1.745 

19 

12.4 

1.095 

63 

34.6 

1.315 

107 

50.3 

1.535 

150 

61  8 

1.750 

20 

13.0 

1.100 

64 

35.0 

1.320 

108 

50.6 

1.540 

151 

62.1 

1  755 

21 

13.6 

1.105 

65 

35.4 

1.325 

109 

50.9 

1.545 

152 

62.3 

1.760 

22 

14.2 

1.110 

66 

35.8 

1.330 

110 

51.2 

1.550 

153 

62.5 

1.765 

23 

14.9 

1.115 

67 

36.2 

1.335 

111 

51.5 

1.555 

154 

62.8 

1.770 

24 

15.4 

1.120 

68 

36.6 

1.340 

112 

51.8 

1.560 

155 

63.0 

1.775 

25 

16.0 

1.125 

69 

37.0 

1.345 

113 

52.1 

1.565 

156 

63.2 

1.780 

26 

16.5 

1.130 

70 

37.4 

1  350 

114 

52.4 

1.570 

157 

63.5 

1.785 

27 

17.1 

1.135 

71 

37.8 

1.355 

115 

52.7 

1.575 

158 

63.7 

1.790 

28 

17.7 

1.140 

72 

38.2 

1.360 

116 

53.0 

1.580 

159 

64.0 

1.795 

29 

18.3 

1.145 

73 

38.6 

1.365 

117 

53.3 

1.585 

160 

64.2 

1.800 

30 

18.8 

1.150 

74 

39.0 

1.370 

118 

53.6 

1.590 

161 

64.4 

1.805 

31 

19.3 

1.155 

75 

39.4 

1.375 

119 

53.9 

1.595 

162 

64.6 

1.810 

32 

19.8 

1.160 

76 

39.8 

1.380 

120 

54.1 

1.600 

163 

64.8 

1.815 

33 

20.3 

1.165 

77 

40.1 

1.385 

121 

54.4 

1.605 

164 

65.0 

1.820 

34 

20.9 

1.170 

78 

40.5 

1.390 

122 

54.7 

1.610 

165 

65.2 

1.825 

35 

21.4 

1.175 

79 

40.8 

1.395 

123 

55.0 

1.615 

166 

65.5 

1.830 

36 

22.0 

1.180 

80 

41.2 

1.400 

124 

55.2 

1.620 

167 

65.7 

1.835 

37 

22.5 

1.185 

81 

41.6 

1.405 

125 

55.5 

1.625 

168 

65.9 

1.840 

38 

23.0 

1.190 

82 

42.0 

1.410 

126 

55.8 

1.630 

169 

66.1 

1.845 

39 

23.5 

1.195 

83 

42.3 

1.415 

127 

56.0 

1.635 

170 

66.3 

1.850 

40 

24.0 

1.200 

84 

42.7 

1.420 

128 

56.3 

1.640 

171 

66.5 

1.855 

41 

24.5 

1.205 

85 

43.1 

1.425 

129 

56.6 

1.645 

172 

66.7 

1.860 

42 

25.0 

1.210 

86 

43.4 

1.430 

130 

56.9 

1.650 

173 

67.0 

1.865 

43 

25.5 

1.215 

87 

43.8 

1.435 

570 


APPENDIX. 


5.   Comparison  between  Specific  Gravity  Figures,  Degree  Baume  and  Degree 
Brix  (as  used  for  sugar  solutions). 


Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

Degree 
Baume. 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix 

Specific 
gravity. 

•0) 

.1 

£3 

MlM 
o>W 

ft 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix 

Specific 
gravity. 

•aj 

*s 

o>  3 
j-  ri 

Sw 

« 

0.0 

1.00000 

0.00 

5.0 

1.01970 

2.84 

10.0 

1.04014 

5.67 

0.1 

1.00038 

0.06 

5.1 

1.02010 

2.89 

10.1 

1.04055 

572 

0.2 

1.00077 

Oil 

5.2 

1.02051 

2.95 

10.2 

1.04097 

5.78 

0.3 

1.00116 

0.17 

5.3 

1.02091 

3.01 

10.3 

1.04139 

5.83 

0.4 

1  00155 

0.23 

6.4 

1.02131 

3.06 

10.4 

1.04180 

5.89 

0.5 

1.00193 

0.28 

5.5 

1.02171 

3.12 

10.5 

1.04222 

5.95 

0.6 

1.00232 

0.34 

5.6 

1.02211 

3.18 

10.6 

1.04264 

6.00 

0.7 

1.00271 

0.40 

5.7 

1.02252 

3.23 

10.7 

1.04306 

6.06 

08 

1.00310 

0.45 

6.8 

1.02292 

3.29 

10.8 

1.04348 

6.12 

0.9 

1.00349 

0.51 

6.9 

1.02333 

3.35 

10.9 

1.04390 

6.17 

1.0 

1.00388 

0.57 

6.0 

1.02373 

3.40 

11.0 

1.04431 

6.23 

1.1 

1.00427 

0.63 

6.1 

1.02413 

3.46 

11.1 

1.04473 

6.29 

1.2 

1.00466 

0.68 

6.2 

1.02454 

3.52 

11.2 

1.04515 

6.34 

1.3 

1.00505 

0.74 

6.3 

1.02494 

3.57 

11.3 

1.04557 

6.40 

1.4 

1.00544 

080 

6.4 

1.02535 

3.63 

11.4 

1.04599 

6.46 

1.5 

1.00583 

0.85 

6.6 

1.02575 

3.69 

11.5 

1.04641 

6.51 

1.6 

1.00622 

0.91 

6.6 

1.02616 

3.74 

11.6 

1.04683 

6.57 

1.7 

1.00662 

0.97 

6.7 

1.02657 

380 

11.7 

1.04726 

6.62 

1.8 

1.00701 

1.02 

6.8 

1.02697 

3.86 

11.8 

1.04768 

6.68. 

1.9 

1.00740 

1.08 

6.9 

1.02738 

3.91 

11.9 

1.04810 

6.74 

2.0 

1.00779 

1.14 

7.0 

1.02779 

3.97 

12.0 

1.04852 

6.79 

2.1 

1.00818 

1.19 

7.1 

1.02819 

4.03 

12.1 

1.04894 

6.85 

2.2 

1.00858 

1.25 

7.2 

1.02860 

4.08 

12.2 

1.04937 

6.91 

2.3 

1.00897 

1.31 

7.3 

1.02901 

4.14 

12.3 

1.04979 

6.96 

2.4 

1.00936 

1.36 

7.4 

1.02942 

4.20 

12.4 

1.05021 

7.02 

2.5 

1.00976 

1.42 

7.5 

1.02983 

4.25 

12.5 

1.05064 

7.08 

2.6 

1.01015 

1.48 

7.6 

1.03024 

4.31 

12.6 

1.05106 

7.13 

2.7 

1.01055 

1.53 

7.7 

1.03064 

4.37 

12.7 

1.05149 

7.19 

2.8 

1.01094 

1.59 

7.8 

1.03105 

4.42 

128 

1.05191 

7.24 

2.9 

1.01134 

1.65 

7.9 

1.03146 

4.48 

12.9 

1.05233 

7.30 

8.0 

1.01173 

1.70 

8.0 

1.03187 

4.53 

13.0 

1.05276 

7.36 

3.1 

1.01213 

1.76 

8.1 

1.03228 

4.59 

13.1 

1.05318 

7.41 

3.2 

1.01252 

1.82 

8.2 

1.03270 

4.65 

13.2 

1.05361 

7.47 

3.3 

1.01292 

1  87 

8.3 

1.03311 

4.70 

13.3 

1.05404 

7.53 

3.4 

1.01332 

1.93 

8.4 

1.03352 

4.76 

13.4 

1.05446 

7.58 

3.5 

1.01371 

1.99 

8.5 

1.03393 

4.82 

13.5 

1.05489 

7.64 

3.6 

1.01411 

2.04 

8.6 

1.03434 

4.87 

13.6 

1.05532 

7.69 

3.7 

1.01451 

2.10 

8.7 

1.03475 

4.93 

13.7 

1.05574 

7.75 

3.8 

1.01491 

2.16 

8.8 

1.03517 

4.99 

13.8 

1.05617 

7.81 

3.9 

1.01531 

2.21 

8.9 

1.03558 

5.04 

13.9 

1.05660 

7.86 

4.0 

1.01570 

2.27 

9.0 

1.03599 

5.10 

14.0 

1  05703 

7.92 

4.1 

1.01610 

2.33 

9.1 

1.03640 

5.16 

14.1 

1.05746 

7.98 

4.2 

1.01650 

2.38 

9.2 

1.03682 

5.21 

14.2 

1.05789 

8.03 

4.3 

1.01690 

2.44 

9.3 

1.03723 

5.27 

14.3 

1.05831 

8.09 

4.4 

1.01730 

250 

9.4 

1.03765 

5.33 

14.4 

1.05874 

8.14 

4.5 

1.01770 

2.55 

9.5 

1.03806 

5.38 

14.5 

1.05917 

8.20 

4.6 

1.01810 

2.61 

9.6 

1.03848 

5.44 

14.6 

1.05960 

8.26 

4.7 

1  01850 

2.67 

9.7 

1.03889 

5.50 

14.7 

1.06003 

831 

4.8 

1.01890 

2.72 

9.8 

1.03931 

5.55 

14.8 

1.06047 

8.37 

4.9 

1.01930 

2.78 

9.9 

1.03972 

561 

14.9 

1.06090 

8.43 

APPENDIX. 


571 


Comparison  between  Specific  Gravity  Figures,  Degree  Baume  and  Degree 

Brix. — Continued. 


Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

Degree 
Baume. 

1 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

Degree 
Baum6. 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

•aj 
$3 

Q)  3l 

a 

15.0 

1.06133 

8.48 

20.0 

1.08329 

11.29 

25.0 

1.10607 

14.08 

15.1 

1.06176 

8.54 

20.1 

1.08374 

11.34 

25.1 

1.10653 

14.13 

15.2 

1.06219 

8.59 

20.2 

1.08419 

11.40 

25.2 

1.10700 

14.19 

15.3 

1.06262 

8.65 

20.3 

1.08464 

11.45 

25.3 

1.10746 

14.24 

15.4 

1.06306 

8.71 

20.4 

1.08509 

11.51 

25.4 

1.10793 

14.30 

15.5 

1.06349 

8.76 

20.5 

1.08553 

11  57 

25.5 

1.10839 

14.35 

15.6 

1.06392 

8.82 

206 

1.08599 

11.62 

25.6 

1.10886 

14.41 

15.7 

1.06436 

8.88 

20.7 

1.08643 

11  68 

25.7 

1.10932 

14.47 

15.8 

1.06479 

8.93 

20.8 

1.08688 

11.73 

25.8 

1.10979 

14.52 

15.9 

1.06522 

8.99 

20.9 

1.08133 

11.79 

25.9 

1.11026 

14.58 

16.0 

1.06566 

9.04 

21.0 

1.08778 

11.85 

26.0 

1.11072 

14.63 

16.1 

1.06609 

9.10 

21.1 

1.08824 

11.90 

26.1 

1.11119 

14.69 

.  16.2 

1.06653 

9.16 

21.2 

1.08869 

11.96 

26.2 

1.11166 

14.74 

16.3 

1.06696 

9.21 

21.3 

1.08914 

12.01 

26.3 

1.11213 

14.80 

16.4 

1.06740 

9.27 

21.4 

1.08959 

12.07 

26.4 

1.11259 

14.85 

16.5 

1.06783 

9.33 

21.5 

1.09004 

12.13 

26.5 

1.11306 

14.91 

16.6 

1.06827 

9.38 

21.6 

1.09049 

12.18 

26.6 

1.11353 

14.97 

16.7 

1.06871 

9.44 

21.7 

1.09095 

12.24 

26.7 

1.11400 

15.02 

16.8 

1.06914 

9.49 

21.8 

1.09140 

1229 

26.8 

1.11447 

15.08 

16.9 

1.06958 

9.55 

21.9 

1.09185 

12.35 

26.9 

1.11494 

16.13 

17.0 

1.07002 

9.61 

22.0 

1.09231 

12.40 

27.0 

1.11541 

15.19 

17.1 

1.07046 

9.66 

22.1 

1.09276 

12.46 

27.1 

1.11588 

15.24 

17.2 

1.07090 

9.72 

22.2 

1.09321 

12.52 

27.2 

1.11635 

15.30 

17.3 

1.07133 

9.77 

22.3 

1.09367 

12.57 

27.3 

1.11682 

15.35 

17.4 

1.07177 

9.83 

22.4 

1.09412 

12.63 

27.4 

1.11729 

15.41 

17.5 

1.07221 

9.89 

22.5 

1.09458 

12.68 

27.5 

1.11776 

15.46 

17.6 

107265 

9.94 

226 

1.09503 

12.74 

27.6 

1.11824 

15.52 

17.7 

1.07309 

10.00 

22.7 

1  09549 

12.80 

27.7 

1.11871 

15.58 

178 

1.07358 

10.06 

22.8 

1.09595 

12.85 

27.8 

1.11918 

15.63 

17.9 

1.07397 

10.11 

229 

1.09640 

12.91 

27.9 

1.11965 

15.69 

18.0 

1.07441 

10.17 

23.0 

1.09686 

12.96 

28.0 

1.12013 

15.74 

18.1 

1.07485 

10.22 

23.1 

1.09732 

13.02 

28.1 

1.12060 

15.80 

18.2 

1.07530 

10.28 

23.2 

1.09777 

13.07 

28.2 

1.12107 

15.85 

18.3 

1.07574 

10.33 

23.3 

1.09823 

13.13 

28.3 

1.12155 

15.91 

18.4 

1.07618 

10.39 

23.4 

1.09869 

13.19 

28.4 

1.12202 

15.96 

18.5 

1  07662 

10.45 

23.5 

1.09915 

13.24 

28.5 

1.12250 

16.02 

18.6 

1.07706 

10.50 

23.6 

1.09961 

13.30 

28.6 

1.12297 

16.07 

18.7 

1.07751 

10.56 

23.7 

1.10007 

13.35 

28.7 

1.12345 

16.13 

18.8 

1.07795 

10.62 

23.8 

1.10053 

13.41 

28.8 

1.12393 

16.18 

18.9 

1.07839 

10.67 

23.9 

1.10099 

13.46 

28.9 

1.12440 

16.24 

19.0 

1.07884 

10.73 

24.0 

1.10145 

13.52 

29.0 

1.12488 

16.30 

19.1 

1.07928 

10.78 

24.1 

1.10191 

13.58 

29.1 

1.12536 

16.35 

19.2 

1.07973 

10.84 

24.2 

1.10237 

13.63 

29.2 

1.12583 

16.41 

19.8 

1.08017 

10.90 

24.3 

1.10283 

13.69 

29.3 

1.12631 

16.46 

19.4 

1.08062 

10.95 

24.4 

1.10329 

13.74 

29.4 

1.12679 

16.52 

19.5 

1.08106 

11.01 

24.5 

1.10375 

13.80 

29.5 

1.12727 

16.57 

19.6 

1.08151 

11.06 

24.6 

1.10421 

13.85 

29.6 

1.12775 

16.63 

19.7 

108196 

11.12 

24.7 

1.10468 

13.91 

29.7 

1.12823 

16.68 

19.8 

1.08240 

11.18 

24.8 

1.10514 

13.96 

29.8 

1.12871 

16.74 

19.9 

1.08285 

11.27 

24.9 

1.10560 

14.02 

29.9 

1.12919 

16.79 

572 


APPENDIX. 


Comparison  between  Specific  Gravity  Figures,  Degree  Baume  and  Degree 

Brix. — Continued. 


Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

•a! 

wa 
Is 

g>« 

ft 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

Degree 
Baum6. 

1 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

Degree 
Baum6. 

30.0 

1.12967 

16.85 

35.0 

1.15411 

19.60 

40.0 

1.17943 

22.33 

30.1 

1.13015 

16.90 

35.1 

1.15461 

19.66 

40.1 

1.17995 

22.38 

30.2 

1.13063 

16.96 

35.2 

1.15511 

19.71 

40.2 

1.18046 

2-J.44 

30.3 

1.13111 

17.01 

35.3 

1.15561 

19.76 

40.3 

1.18098 

22.49 

30.4 

1.13159 

17.07 

35.4 

1.15611 

19.82 

40.4 

1.18150 

22.55 

30.5 

1.13207 

17.12 

35.5 

1.15661 

19.87 

40.5 

1.18201 

22.60 

30.6 

1.13255 

17.18 

35.6 

1,15710 

19.93 

40.6 

1.18253 

22.66 

30.7 

1.13304 

17.23 

35.7 

1.15760 

19.98 

40.7 

1.18305 

22.71 

30.8 

1.13352 

17.29 

35.8 

1.15810 

20.04 

40.8 

1.18357 

22.77 

30.9 

1.13400 

17.35 

35.9 

1.15861 

20.09 

40.9 

1.18408 

22.82 

31.0 

1.13449 

17.40 

36.0 

1.15911 

20.15 

41.0 

1.18460 

22.87 

31.1 

1.13497 

17.46 

36.1 

1.15961 

20.20 

41.1 

1.18512 

22.93 

31.2 

1.13545 

17.51 

36.2 

1.16011 

20.26 

41.2 

1.18564 

22.98 

31.3 

1.13594 

17.57 

36.3 

1.16061 

20.31 

41.3 

1.18616 

23.04 

31.4 

1.13642 

17.62 

36.4 

1.16111 

20.37 

41.4 

1.18668 

23.09 

31.5 

1.13691 

17.68 

36.5 

1.16162 

20.42 

41.5 

1.18720 

23.15 

31.6 

1.13740 

17.73 

36.6 

1.16212 

20.48 

41.6 

1.18772 

23.20 

31.7 

1.13788 

17.79 

36.7 

1.16262 

20.53 

41.7 

1.18824 

23.25 

31.8 

1.13837 

17.84 

36.8 

1.16313 

20.59 

41.8 

1.18887 

23.31 

31.9 

1.13885 

17.90 

36.9 

1.16363 

20.64 

41.9 

1.18929 

23.36 

32.0 

1.13934 

17.95 

37.0 

1.16413 

20.70 

42.0 

1.18981 

23.42 

32.1 

1.13983 

18.01 

37.1 

1.16464 

20.75 

42.1 

1.19033 

23.47 

32.2 

1.14032 

18.06 

37.2 

1.16514 

20.80 

42.2 

1.19086 

23.52 

32.3 

1.14081 

18.12 

37.3 

1.16565 

20.86 

42.3 

1.19138 

23.58 

32.4 

1.14129 

18.17 

37.4 

1.16616 

20.91 

42.4 

1.19190 

28.63 

32.5 

1.14178 

18.23 

37.5 

1.16666 

20.97 

42.5 

1.19243 

23.69 

32.6 

1.14227 

18.28 

37.6 

1.16717 

21.02 

42.6 

1.19295 

23.74 

32.7 

1.14276 

18.34 

37.7 

1.16768 

21.08 

42.7 

1.19348 

23.79 

32.8 

1.14325 

18.39 

37.8 

1.16818 

21.13 

42.8 

1.19400 

23.85 

32.9 

1.14374 

18.45 

37.9 

1.16869 

21.19 

42.9 

1.19453 

23.90 

33.0 

1.14423 

18.50 

38.0 

1.16920 

21.24 

43.0 

1.19505 

23.96 

33.1 

1.14472 

18.56 

38.1 

1.16971 

21.30 

43.1 

1.19558 

24.01 

33.2 

1.14521 

18.61 

38.2 

1.17022 

21.35 

43.2 

1.19611 

24.07 

33.3 

1.14570 

18.67 

38.3 

1.17072 

21.40 

43.3 

1.19663 

24.12 

33.4 

1.14620 

18.72 

38.4 

1.17122 

21.46 

43.4 

1.19716 

24.17 

33.5 

1.14669 

18.78 

38.5 

1.17174 

21.51 

43.5 

1.19769 

24.23 

33.6 

1.14718 

18.83 

38.6 

1.17225 

21.57 

43.6 

1.19822 

24.28 

33.7 

1.14767 

18.89 

38.7 

1.17276 

21.62 

43.7 

1.19875 

24.34 

33.8 

1.14817 

18.94 

38.8 

1.17327 

21.68 

43.8 

1.19927 

24.39 

33.9 

1.14866 

19.00 

38.9 

1.17379 

21.73 

43.9 

1.19980 

24.44 

34.0 

1.14915 

19.05 

39.0 

1.17430 

21.79 

44.0 

1.20033 

24.50 

34.1 

1.14965 

19.11 

39.1 

1.17481 

21.84 

44.1 

1.20086 

24.55 

34.2 

1.15014 

19.16 

39.2 

1.17532 

21.90 

44.2 

1.20139 

24.61 

34.3 

1.15064 

19.22 

39.3 

1.17583 

21.95 

,      44.3 

1.20192 

24.66 

34.4 

1.15113 

19.27 

39.4 

1.17635 

22.00 

44.4 

1.20245 

24.71 

34.5 

1.15163 

19.33 

39.5 

1.17686 

22.06 

44.5 

1.20299 

24.77 

34.6 

1.15213 

19.38 

39.6 

1.17737 

22.11 

44.6 

1.20352 

24.82 

34.7 

1.15262 

19.44 

39.7 

1.17789 

22.17 

44.7 

1.20405 

24.88 

34.8 

1.15312 

19.49 

39.8 

1.17840 

22.22 

44.8 

1.20458 

24.93 

34.9 

1.15362 

19.55 

39.9 

1.17892 

22.28 

44.9 

1.20512 

24.98 

i 

APPENDIX. 


573 


Comparison  between  Specific  Gravity  Figures,  Degree  Baume  and  Degree 

Brix. — Continued. 


Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

XU 

<uS 
flj  3 
M-q 
Q 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

Degree 
Baume'. 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

•aJ 

ci 

as 

45.0 

1.20565 

25.04 

50.0 

1.23278 

27.72 

55.0 

1.26086 

30.37 

45.1 

1.20618 

25.09 

50.1 

1.23334 

27.77 

55.1 

1.26143 

30.42 

45.2 

1.20672 

25.14 

50.2 

1.23389 

27.82 

55.2 

1.26200 

30.47 

45.3 

1.20725 

25.20 

50.3 

1.23444 

27.88 

55.3 

1.26257 

30.53 

45.4 

1.20779 

25.25 

50.4 

1.23499 

27.93 

55.4 

1.26314 

30.58 

45.5 

1.20832 

25.31 

50.5 

1.23555 

27.98 

55.5 

1.26372 

30.63 

45.6 

1.20886 

25.36 

50.6 

1.23610 

28.04 

55.6 

1.26429 

30.68 

45.7 

1.20939 

25.41 

50.7 

1.23666 

28.09 

55.7 

1.26486 

30.74 

45.8 

1.20993 

25.47 

50.8 

1.23721 

28.14 

55.8 

1.26544 

30.79 

45.9 

1.21046 

25.52 

50.9 

1.23777 

28.20 

55.9 

1.26601 

30.84 

46.0 

1.21100 

25.57 

51.0 

1.23832 

28.25 

56.0 

1.26658 

30.89 

46.1 

1.21154 

25.63 

51.1 

1.23888 

28.30 

66.1 

1.26716 

30.95 

46.2 

1.21208 

25.68 

51.2 

1.23943 

28.36 

56.2 

1.26773 

31.00 

46.3 

1.21261 

25.74 

51.3 

1.23999 

28.41 

56.3 

1.26831 

31.05 

46.4 

1.21315 

25.79 

51.4 

1.24055 

2*.46 

56.4 

1.26889 

31.10 

46.5 

1.21369 

25.84 

51.5 

1.24111 

28.51 

56.5 

1.26946 

31.16 

46.6 

1.21423 

25.90 

51.6 

1.24166 

28.57 

56.6 

1.27004 

31.21 

46.7 

1.21477 

25.95 

51.7 

1.24222 

28.62 

56.7 

1.27062 

31.26 

46.8 

1.21531 

26.00 

51.8 

1.24278 

28.67 

56.8 

1.27120 

31.31 

46.9 

1.21585 

26.06 

51.9 

1.24334 

28.73 

66.9 

1.27177 

31.37 

47.0 

1.21639 

26.11 

52.0 

1.24390 

28.78 

57.0 

1.27235 

31.42 

47.1 

1.21693 

26.17 

52.1 

1.24446 

28.83 

57.1 

1.27293 

31.47 

47.2 

1.21747 

26.22 

52.2 

1.24502 

28.89 

57.2 

1.27351 

31.52 

47.3 

1.21802 

26.27 

52.3 

1.24558 

28.94 

57.3 

1.27409 

31.58 

47.4 

1.21856 

26.33 

52.4 

1.24614 

28.99 

57.4 

1.27467 

31.63 

47.5 

1.21910 

26.38 

52.5 

1.24670 

29.05 

57.5 

1.27525 

31.68 

47.6 

1.21964 

26.43 

52.6 

1.24726 

29.10 

57.6 

1.27583 

31.73 

47.7 

1.22019 

26.49 

52.7 

1.24782 

29.15 

57.7 

1.27641 

31.79 

47.8 

1.22073 

26.54 

52.8 

1.24839 

29.20 

57.8 

1.27699 

31.84 

47.9 

1.22127 

26.59 

52.9 

1.24895 

29.26 

57.9 

1.27758 

31.89 

48.0 

1.22182 

26.65 

53.0 

1.24951 

29.31 

58.0 

1.27816 

31.94 

48.1 

1.22236 

26.70 

53.1 

1.25008 

29.36 

58.1 

1.27874 

32.00 

48.2 

1.22291 

26.75 

53.2 

1.25064 

29.42 

58.2 

1.27932 

32.05 

48.3 

1.22345 

26.81 

53.3 

1.25120 

29.47 

58.3 

1.27991 

32.10 

48.4 

1.  '22400 

26.86 

53.4 

1.25177 

29.52 

58.4 

1.28049 

32.15 

48.5 

1.22455 

26.92 

53.5 

1.25233 

29.57 

58.5 

1.28107 

32.20 

48.6 

1.22509 

26.97 

53.6 

1.25290 

29.63 

58.6 

1.28166 

32.26 

48.7 

1.22564 

27.02 

53.7 

125347 

29.68 

58.7 

1.28224 

32.31 

48.8 

1.22619 

27.08 

53.8 

1.25403 

29.73 

58.8 

1.28283 

32.36 

48.9 

1.22673 

27.13 

53.9 

1.25460 

29.79 

58.9 

1.28342 

32.41 

49.0 

1.22728 

27.18 

54.0 

1.25517 

29.84 

59.0 

1.28400 

32.42 

49.1 

1.22783 

27.24 

54.1 

1.25573 

29.89 

59.1 

1.28459 

32.52 

49.2 

1.22838 

27.29 

54.2 

1.25630 

29.94 

59.2 

1.28518 

32.57 

49.3 

1.22893 

27.34 

54.3 

1.25687 

30.00 

59.3 

1.28576 

32.62 

49.4 

1.22948 

27.40 

54.4 

1.25744 

30.05 

59.4 

1.28635 

32.67 

49.5 

1.23003 

27.45 

54.5 

1.25801 

30.10 

59.5 

1.28694 

32.73 

49.6 

1.23058 

27.50 

54.6 

1.25857 

30.16 

59.6 

1.28753 

32.78 

49.7 

1.23113 

27.56    I 

54.7 

1.25914 

30.21 

59.7 

1.28812 

32.83 

49.8 

1.23168 

27.61 

54.8 

1.25971 

30.26 

59.8 

1.28871 

32.88 

49.9 

1.23223 

27.66 

54.9 

1.26028 

30.31 

59.9 

1.28930 

32.93 

574 


APPENDIX. 


Comparison  between  Specific  Gravity  Figures,  Degree  Baume  and  Degree 

Brix. — Continued. 


Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix 

Specific 
gravity. 

VU 

R! 

£g 
•« 

Q 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix 

Specific 
gravity. 

to 

«8 

a>  3 

ft* 

« 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix 

Specific 
gravity. 

•oJ 

ti 

y 

|B 

60.0 

1.28989 

32.99 

65.0 

1.31989 

35.57 

700 

1.35088 

38.12 

60.1 

1.29048 

33.04 

65.1 

1.32050 

35.63 

70.1 

1.35155 

38.18 

60.2 

1.29107 

33.09 

65.2 

1.32111 

35.68 

70.2 

1.35214 

38.23 

60.3 

1.29166 

33.14 

65.3 

1.32172 

35.73 

70.3 

1.35277 

38.28 

60.4 

1.29225 

33.20 

65.4 

1.32233 

35.78 

70.4 

1.35340 

38.33 

60.5 

1.29284 

33.25 

65.5 

1.32294 

35.83 

70.5 

1.35403 

38.38 

60.6 

1.29343 

33.30 

65.6 

1.32355 

35.88 

70.6 

1.35406 

38.43 

60.7 

1.29403 

33.35 

65.7 

1.32417 

35.93 

70.7 

1.35530 

38.48 

60.8 

1.29462 

33.40 

65.8 

1.32478 

35.98 

70.8 

1.35593 

38.53 

60.9 

1.29521 

33.46 

65.9 

1.32539 

36.04 

70.9 

1.35050 

38.58 

61.0 

1.29581 

33.51 

66.0 

1.32001 

30.09 

71.0 

1.35720 

38.63 

61.1 

1.29646 

33.56 

66.1 

1.32662 

36.14 

71.1 

1.35783 

38.68 

61.2 

1.29700 

33.61 

66.2 

1.32724 

36.19 

71.2 

1.35847 

38.73 

61.3 

1.29759 

33.66 

66.3 

1.32785 

36.24 

71.3 

1.35910 

38.78 

61.4 

1.29819 

33.71 

66.4 

1.32847 

30.29 

71.4 

1.35974 

38.83 

61.5 

1.29878 

33.77 

66.5 

1.32908 

30.34 

71.5 

1.30037 

38.88 

61.6 

1.29938 

33.82 

66.6 

1.32970 

36.39 

71.6 

1.30101 

38.93 

61.7 

1.29998 

33.87 

66.7 

1.33031 

36.45 

71.7 

1.36164 

38.98 

61.8 

1.30057 

33.92 

66.8 

1.33093 

36.50 

71.8 

1.36228 

39.03 

61.9 

1.30117 

33.97 

66.9 

1.3315-3 

30.55 

71.9 

1.36292 

39.08 

62.0 

1.30177 

34.03 

67.0 

1.33217 

36.60 

72.0 

1.36355 

39.13 

62.1 

1.30237 

34.08 

67.1 

1.33278 

36.65 

72.1 

1.36419 

39.19 

62.2 

1.30297 

34.13 

67.2 

1.33340 

36.70 

72.2 

1.36483 

39.24 

62.3 

1.30356 

34.18 

67.3 

1.33402 

36.75 

72.3 

1.36547 

39.29 

62.4 

1.30416 

34.23 

67.4 

1.33464 

30.80 

72.4 

1.36611 

39.34 

62.5 

1.30476 

34.28 

67.5 

1.33526 

36.85 

72.5 

1.36675 

39.39 

62.6 

1.30536 

34.34 

67.6 

1.33588 

36.90 

726 

1.36739 

39.44 

62.7 

1.30596 

34.39 

67.7 

1.33650 

36.96 

72.7 

1.36803 

39.49 

62.8 

1.30657 

34.44 

67.8 

1.33712 

37.01 

72.8 

1.36867 

39.54 

62.9 

1.30717 

34.49 

67.9 

1.33774 

37.06 

72.9 

1.36931 

39.59 

63.0 

1.30777 

34.54 

68.0 

1.33836 

37.11 

73.0 

1.36995 

39.64 

63.1 

1.30837 

34.59 

68.1 

1.33899 

37.16 

73.1 

1.37059 

39.09 

63.2 

1.30897 

34.65 

68.2 

1.33961 

37.21 

73.2 

1.37124 

39.74 

63.3 

1.30958 

34.70 

68.3 

1.34023 

37.26 

73.3 

1.37188 

39.79 

63.4 

1.31018 

34.75 

68.4 

1.34085 

37.31 

73.4 

1.37252 

39.84 

63.5 

1.31078 

34.80 

68.5 

1.34148 

37.36 

73.5 

1.37317 

39.89 

63.6 

1.31139 

34.85 

68.6 

1.34210 

37.41 

73.6 

1.37381 

39.94 

63.7 

1.31199 

34.90 

68.7 

1.34273 

37.47 

73.7 

1.37446 

39.99 

63.8 

1.31260 

34.96 

68.8 

1.34335 

37.52 

73.8 

1.37510 

40.04 

63.9 

1.31320 

35.01 

68.9 

1.34398 

37.57 

73.9 

1.37575 

40.09 

64.0 

1.31381 

35.06 

69.0 

1.34460 

37.62 

74.0 

1.37039 

40.14 

64.1 

1.31442 

35.11 

69.1 

1.34523 

37.67 

74.1 

1.37704 

40.19 

64.2 

1.31502 

35.16 

69.2 

1.34525 

37.72 

74.2 

1.37768 

40.24 

64.3 

1.31563 

35.21 

69.3 

1.34648 

37.77 

•>    74.3 

1.37833 

40.29 

64.4 

1.31624 

35.27 

69.4 

1.34711 

37.82 

74.4 

1.37898 

40.34 

64.5 

1.31684 

35.32 

69.5 

1.34774 

37.87 

74.5 

1.37962 

40.39 

64.6 

1.31745 

35.37 

69.6 

1.34836 

37.92 

74.6 

1.38027 

40.44 

64.7 

1.31806 

35.42 

69.7 

1.34899 

37.97 

74.7 

1.38092 

40.49 

64.8 

1.31867 

35.47 

69.8 

1.34962 

38.02 

74.8 

1.38157 

40.54 

64.9 

1.31928 

35.52 

69.9 

1.35025 

38.07 

74.9 

1.38222 

40.59 

APPENDIX. 


575 


Comparison  between  Specific  Gravity  Figures,  Degree  Bourne  and  Degree 

Brix. — Continued. 


Percentage 

-«5 

Percentage 

•o 

Percentage 

«4> 

of  sugar  ac- 
cording to 
Balling  or 

Specific 
gravity. 

•i 

<u  a 

>-.aJ 

£w 

of  sugar  ac- 
cording to 
Balling  or 

Specific 
gravity. 

a>S 
-    S  3 

§4 

of  sugar  ac- 
cording to 
Balling  or 

Specific 
gravity. 

*s 

o  3 

m 

degree  Brix. 

p 

degree  Brix. 

o 

degree  Brix 

o 

75.0 

1.38287 

40.64 

80.0 

1.41586 

43.11 

85.0 

1.44986 

45.54 

75.1 

1.38352 

40.69 

80.1 

1.41653 

43.61 

85.1 

1.45055 

45.59 

75.2 

1.38417 

40.74 

80.2 

1.41720 

43.21 

85.2 

1.45124 

45.64 

75.3 

1.38482 

40.79 

80.3 

1.41787 

43.26 

85.3 

1.45193 

45.69 

75.4 

1.38547 

40.84 

80.4 

1.41854 

43.31 

85.4 

1.45262 

45.74 

75.5 

1.38612 

40.89 

80.5 

1.41921 

43.36 

85.5 

1.45331 

45.78 

75.6 

1.38677 

40.94 

80.6 

1.41989 

43.41 

85.6 

1.45401 

45.83 

75.7 

1.38743 

40.99 

80.7 

1.42056 

43.45 

85.7 

1.45470 

45.88 

75.8 

1.38808 

41.04 

80.8 

1.42123 

43.50 

85.8 

1.  45539 

45.93 

75.9 

1.38873 

41.09 

80.9 

1.42190 

43.55 

85.9 

1.45609 

45.98 

76.0 

1.38939 

41.14 

81.0 

1.42258 

43.60 

86.0 

1.45678 

46.  0'-' 

76.1 

1.39004 

41.19 

81.1 

1.42325 

43.65 

86.1 

1.45748 

46.07 

76.2 

1.39070 

41.24 

81.2 

1.42393 

43.70 

86.2 

1.45817 

46.12 

76.3 

1.39135 

41.29 

81.3 

1.42460 

43.75 

86.3 

1.45887 

46.17 

76.4 

1.39201 

41.33 

81.4 

1.42528 

43.80 

86.4 

1.45956 

46.22 

76.5 

1.39266 

41.38 

81.5 

1.42595 

43.85 

86.5 

1.46026 

46.26 

76.6 

1.39332 

41.43 

81.6 

1.42663 

43.89 

86.6 

1.46095 

46.31 

76.7 

1.39397 

41.48 

81.7 

1.42731 

43.94 

86.7 

1.46165 

46.36 

76.8 

1.39463 

41.53 

81.8 

1.42798 

43.99 

86.8 

1.46235 

46.41 

76.9 

1.39529 

41.58 

81.9 

1.42866 

44.04 

86.9 

1.46304 

46.46 

77.0 

1.39595 

41.63 

82.0 

1.42934 

44.09 

87.0 

L  46374 

46.50 

77.1 

1.39660 

41.68 

82.1 

1.43002 

44.14 

87.1 

1.46444 

46.55 

77.2 

1.39726 

41.73 

82.2 

1.43070 

44.19 

87.2 

1.46514 

46.60 

77.3 

1.39792 

41.78 

82.3 

1.43137 

44.24 

87.3 

1.46584 

46.65 

77.4 

1.39858 

41.83 

82.4 

1.43205 

44.28 

87.4 

1.46654 

46.69 

77.5 

1.39924 

41.88 

82.5 

1.43273 

44.33 

87.5 

1.46724 

46.74 

77.6 

1.39990 

41.93 

82.6 

1.43341 

44.38 

87.6 

1.46794 

46.79 

77.7 

1.40056 

41.98 

82.7 

1.43409 

44.43 

87.7 

1.46864 

46.84 

77.8 

1.40122 

42.03 

82.8 

1.43478 

44.48 

87.8 

1.46934 

46.88 

77.9 

1.40188 

42.08 

82.9 

1.43546 

44.53 

87.9 

1.47004 

46.93 

78.0 

1.40254 

42.13 

83.0 

1.43614 

44.58 

88.0 

1.47074 

46.98 

78.1 

1.40321 

42.18 

83.1 

1.43682 

44.62 

88.1 

1.47145 

47.03 

78.2 

1.40387 

42.23 

83.2 

1.43750 

44.67 

88.2 

1.47215 

47.08 

78.3 

1.40453 

42.28 

83.3 

1.43819 

44.72 

88.3 

1.47285 

47.12 

78.4 

1.40520 

42.32 

83.4 

1.43887 

44.77 

88.4 

1.47356 

47.17 

78.5 

1.40586 

42.37 

83.5 

1.43955 

44.82 

88.5 

1.47426 

47.22 

78.6 

1.40652 

42.42 

83.6 

1.44024 

44.87 

88.6 

1.47496 

47.27 

78.7 

1.40719 

42.47 

83.7 

1.44092 

44.91 

88.7 

1.47567 

47.31 

78.8 

1.40785 

42.52 

83.8 

1.44161 

44.96 

88.8 

1.47637 

47.36 

78.9 

1.40852 

42.57 

83.9 

1.44229 

45.01 

88.9 

1.47708 

47.41 

79.0 

1.40918 

42.62 

84.0 

1.44298 

45.06 

89.0 

1.47778 

47.46 

79.1 

1.40985 

42.67 

84.1 

1.44367     45.11 

89.1 

1.47849 

47.50 

79.2 

1.41052 

42.72 

84.2 

1.44435  !  45.16 

89.2 

1.47920 

47.55 

79.3 

1.41118 

42.77 

84.3 

1.44504 

45.21 

89.3 

1.47991 

47.60 

79.4 

1.41185 

42.82 

84.4 

1.44573 

45.25 

89.4 

1.48061 

47.65 

79.5 

1.41252 

42.87 

84.5 

1.44fi41 

45.30 

89.5 

1.48132 

47.69 

79.6 

1.41318 

42.92 

84.6 

1.44710 

45.35 

89.6 

1.48203 

47.74 

79.7 

1.41385 

42.96 

84.7 

1.44779 

45.40 

89.7 

1.48274 

47.79 

79.8 

1.41452 

43.01 

84.8 

1.44848 

45.45 

89.8 

1.48345 

47.83 

79.9 

1.41519 

43.06 

84.9 

1.44917 

45.49 

89.9 

1.48416 

47.88 

576 


APPENDIX. 


Comparison  between  Specific  Gravity  Figures,  Degree  Baume  and  Degree 

Brix. — Continued. 


Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

M> 
.1 
|| 

Q 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

Degree 
Baume. 

Percentage 
of  sugar  ac- 
cording to 
Balling  or 
degree  Brix. 

Specific 
gravity. 

Degree 
Baume'. 

90.0 

1.48486 

47.93 

94.0 

1.51359 

49.81 

98.0 

1.54290 

51.65 

90.1 

1.48558 

47.98 

94.1 

1.51431 

49.85 

98.1 

1.54365 

51.70 

90.2 

1.48629 

48.02 

94.2 

1.51504 

49.90 

98.2 

1.54440 

51.74 

90.3 

1.48700 

48.07 

94.3 

1.51577 

49.94 

98.3 

1.54515 

51.79 

90.4 

1.48771 

48.12 

94.4 

1.51649 

49.99 

98.4 

1.54590 

51.83 

90.5 

1.48842 

48.17 

94.5 

1.51722 

50.04 

98.5 

1.54665 

51.88 

90.6 

1.48913 

48.21 

94.6 

1.51795 

50.08 

98.6 

1.54740 

51.92 

90.7 

1.48985 

48.26 

94.7 

1.51868 

50.13 

98.7 

1.54815 

51.97 

90.8 

1.49056 

48.31 

94.8 

1.51941 

50.18 

98.8 

1.54890 

52.01 

90.9 

1.49127 

48.35 

94.9 

1.52014 

50.22 

98.9 

1.54965 

52.06 

91.0 

1.49199 

48.40 

95.0 

1.52087 

50.27 

99.0 

1.55040 

52.11 

91.1 

1.49270 

48.45 

95.1 

1.52159 

50.32 

99.1 

1.55115 

52.15 

91.2 

1.49342 

48.60 

95.2 

1.52232 

50.36 

99.2 

1.55189 

62.20 

91.3 

1.49413 

48.54 

95.3 

1.52304 

50.41 

99.3 

1.55264 

52.24 

91.4 

1.49485 

48.59 

95.4 

1.52376 

50.45 

99.4 

1.55338 

52.29 

91.5 

1.49556 

48.64 

95.5 

1.52449 

50.50 

99.5 

1.55413 

52.33 

91.6 

1.49628 

48.68 

95.6 

1.52521 

50.55 

99.6 

1.55487 

52.38 

91.7 

1.49700 

48.73 

95.7 

1.52593 

50.59 

99.7 

1.55562 

52.42 

91.8 

1.49771 

48.78 

95.8 

1.52665 

60.64 

99.8 

1.55636 

52.47 

91.9 

1.49843 

48.82 

95.9 

1.52738 

50.69 

99.9 

1.55711 

52.51 

92.0 

1.49915 

48.87 

96.0 

1.52810 

50.73 

100.0 

1.55785 

52.56 

92.1 

1.49987 

48.92 

96.1 

1.52884 

50.78 

92.2 

1.50058 

48.96 

96.2 

1.52958 

50.82 

92.3 

1.50130 

49.01 

96.3 

1.53032 

50.87 

92.4 

1.50202 

49.06 

96.4 

1.53106     50.92 

92.5 

1.50274 

49.11 

96.5 

1.53180     50.96 

92.6 

1.50346 

49.15 

96.6 

1.53254 

51.01 

92.7 

1.50419 

49.20 

96.7 

1.53328 

51.05 

92.8 

1.50491 

49.25 

96.8 

1.53402 

51.10 

92.9 

1.50563 

49.29 

96.9 

1.53476 

51.15 

93.0 

1.50633 

49.34 

97.0 

1.53550 

51.19 

93.1 

1.50707 

49.39 

97.1 

1.53624 

61.24 

93.2 

1.50779 

49.43 

97.2 

1.53698 

51.28 

93.3 

1.50852 

49.48 

97.3 

1.53772 

51.33 

93.4 

1.50924 

49.53 

97.4 

1.53846 

51.38 

93.5 

1.50996 

49.57 

97.5 

1.53920 

51.42 

93.6 

1.51069 

49.62 

97.6 

1.53994 

51.47 

93.7 

1.51141 

49.67 

97.7 

1.54068 

51.51 

93.8 

1.51214 

49.71 

97.8 

1.54142 

51.56 

93.9 

1.51286 

49.76 

97.9 

1.54216 

51.60 

APPENDIX. 


577 


6.    Table   of   Weight   and   Volume   Relations. 


Degrees 

Baume. 

Specific 
gravity 
25°  C. 

Specific  volume 
(volume  of 
1  kilogram  in 
liters).* 

Weight  of  1 
U.  S.  gallon  in 
pounds 
avoirdupois.f 

Volume  in  U.  S. 
gallons  of  100 
Ibs.  avoirdupois.! 

Weight  of 
1  fluidounce  in 
grains. 

25°  C. 

70 

0.700 

1.4286 

5.819 

17.185 

318.2 

67 

0.710 

1.4085 

5.902 

16.943 

322.8 

64.5 

0.720 

1.3889 

5.985 

16.707 

327.3 

61.8 

0.730 

1.3699 

6.068 

16.479 

331.9 

59 

0.740 

1.3514 

6.151 

16.256 

336.4 

56.5 

0.750 

1.3333 

6.235 

16.039 

341 

54 

0.760 

1.3158 

6.318 

15.828 

345.5 

51.8 

0.770 

1.25)87 

6.401 

15.623 

350 

49.5- 

0.780 

1.2821 

6.484 

15.422 

354.6 

47 

0.790 

1.2658 

6.567 

15.227 

359.1 

45 

0.800 

1.2500 

6.650 

15.037 

363.7 

43 

0.810 

1.2346 

6.733 

14.851 

368.2 

41 

0.820 

1.2195 

6.817 

14.670 

372.8 

38.8 

0.830 

1.2049 

6.900 

14.494 

377.3 

36.8 

0.840 

1.1905 

6.983 

14.321 

381.9 

318 

0.850 

1.1765 

7.066 

14.152 

386.4 

33 

0.860 

1.1628 

7.149 

13.988 

391 

31 

0.870 

1.1494 

7.232 

13.827 

395.5 

29 

0.880 

1.1364 

7.315 

13.670 

400.1 

27.7 

0.890 

1.1236 

7.398 

13.516 

404.6 

25.5 

0.900 

1.1111 

7.481 

13.366 

409.1 

24 

0.910 

1.0989 

7.565 

13.219 

413.7 

22 

0.920 

1.0870 

7.648 

13.075 

418.2 

20.5 

0.930 

1.0753 

7.731 

12.935 

422.8 

19 

0.940 

1.0638 

7.814 

12.797 

427.3 

17.5 

0.950 

1.0526 

7.897 

12.663 

431.9 

15.5 

0.960 

1.0417 

7.980 

12.531 

436.4 

14.2 

0.970 

1.0309 

8.063 

12.401 

441 

13 

0.980 

1.0204 

8.147 

12.275 

445.5 

11.5 

0.990 

1.0101 

8.230 

12.151 

450.1 

10 

1.000 

1.0000 

8.313 

12.029 

454.6 

3 

1.020 

0.9804 

8.479 

11.794 

463.7 

5.7 

1.040 

0.9615 

8.645 

11.567 

472.8 

8.6 

1.060 

0.9434 

8.812 

11.348 

481.9 

10.5 

1.080 

0.9259 

8.978 

11.138 

491 

13 

1.100 

0.9091 

9.144 

10.936 

500.1 

16 

1.120 

0.8929 

9.310 

10.741 

.      509.2 

17.6 

1.140 

0.8772 

9.477 

10.552 

518.3 

20 

1.160 

0.8621 

9.643 

10.370 

527.4 

22 

1.180 

0.8475 

9.809 

10.194 

536.4 

24 

1.200 

0.8333 

9.975 

10.025 

545.5 

26.5 

1.220 

0.8197 

10.142 

9.860 

554.6 

28 

1.240 

0.8065 

10.308 

9.701 

563.7 

29.8 

1.260 

0.7937 

10.474 

9.547 

572.8 

31.6 

1.280 

0.7813 

10.640 

9.398 

581.9 

34 

1.300 

0.7692 

10.807 

9.253 

591.0 

35.2 

1.320 

0.7576 

10.973 

9.113 

600.1 

36.8 

1.340 

0.7463 

11.139 

8.977 

609.2 

38 

1.360 

0.7353 

11.305 

8.845 

618.3 

39.6 

1.380 

0.7246 

11.472 

8.717 

627.4 

41 

1.400 

0.7143 

11.638 

8.592 

636.4 

43 

1.420 

0.7042 

11.804 

8.471 

645.5 

44 

1.440 

0.6944 

11.970 

8.354 

654.6 

45.5 

1.460 

0.6849 

12.137 

8.239 

663.7 

47 

1.480 

0.6757 

12.303 

8.128 

672.8 

48 

1.500 

0.6667 

12.469 

8.020 

681.9 

49.5 

1.520 

0.6579 

12.635 

7.914 

691.0 

51 

1.540 

0.6494 

12.802 

7.811 

700.1 

37 


578  APPENDIX. 

Table  of  Weight  and  Volume  Relations. — Continued. 


Degrees 
Baume. 

Specific 
gravity 
25°  C. 

Specific  volume 
(volume  of 
1  kilogram  in 
liters).* 

Weight  of  1 
U.  S.  gallon  in 
pounds 
avoirdupois,  t 

Volume  in  U.  S. 
gallons  of  100 
Ibs.  avoirdupois.  J 

Weight  of 
1  fluidounce  in 
grains. 

25°  C. 

52 

1.560 

0.6410 

12.968 

7.711 

709.2 

53.4 

1.580 

0.6329 

13.134 

7.614 

718.3 

54.4 

1.600 

0.6250 

13.300 

7.519 

727.4 

55.4 

1.620 

0.6173 

13.467 

7.426 

736.5 

56.6 

1.640 

0.6098 

13.633 

7.335 

745.6 

58 

1.660 

0.6025 

13.799 

7.247 

754.6 

59 

1.680 

0.5952 

13.966 

7.160 

763.7 

60 

1.700 

0.5882 

14.132 

7.076 

772.8 

61 

1.720 

0.5814 

14.298 

6.994 

781.9 

61.7 

1.740 

0.5747 

14.464 

6.913 

791.0 

62.8 

1.760 

0.5682 

14.631 

6.835 

800.1 

63.5 

1.780 

0.5618 

14.797 

6.758 

809.2 

64.2 

1.800 

0.5556 

14.963 

6.683 

818.3 

65.1 

1.820 

0.5495 

15.129 

6.610 

827.4 

66 

1.840 

0.5435 

15.296 

6.538 

836.5 

67.6 

1.860 

0.5376 

15.462 

6.467 

845.6 

68.7 

1.880 

0.5319 

15.628 

6.399 

854.7 

69.5 

1.900 

0.5263 

15.794 

6.331 

863.8 

70.5 

1.920 

0.5208 

15.961 

6.265 

872.8 

71.2 

1.940 

0.5155 

16.127 

6.201 

881.9 

72 

1.960 

0.5102 

16.293 

6.137 

891.0 

73 

1.980 

0.5051 

16.459 

6.075 

900.1 

74 

2.000 

0.5000 

16.626 

6.015 

909.2 

*  Or  of  1  gram  in  cubic  centimeters  ;  strictly  true  only  at  0°  C.  in  vacuo. 

t  Multiply  these  figures  by  2  for  weight  of  one  U.  S.  pint  in  ounces  avoirdupois. 

J  Divide  these^figures  by  2  for  volume  in  pints  of  100  ounces  avoirdupois. 


APPENDIX. 


573 


IV.  Alcohol  Tables. 

Percentage  of  Alcohol  by  Weight  and  by  Volume  from  the  Specific  Gravity 
(at  15.5°  C.),  by  Otto  Hehner. 


Specific 
gravity  a 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  b 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  b 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  b 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

1.0000 

0.00 

0.00 

0.9999 

0.05 

0.07 

0.9949 

2.89 

3.62 

0.9899 

5.94 

7.40 

8 

0.11 

0.13 

8 

2.94 

3.69 

8 

6.00 

7.48 

7 

0.16 

0.20 

7 

3.00 

3.76 

7 

6.07 

7.57 

6 

0.21 

0.26 

6 

3.06 

3.83 

6 

6.14 

7.66 

5 

0.26 

0.33 

5 

3.12 

3.90 

5 

6.21 

7.74 

4 

0.32 

0.40 

4 

3.18 

3.98 

4 

6.28 

7.83 

3 

0.37 

0.46 

3 

3.24 

4.05 

3 

6.36 

7.92 

2 

0.42 

0.53 

2 

3.29 

4.12 

2 

6.43 

8.01 

1 

0.47 

0.60 

1 

3.35 

4.20 

1 

6.50 

8.10 

0 

0.53 

0.66 

0 

3.41 

4.27 

0 

6.57 

8.18 

0.9989 

0.58 

0.73 

0.9939 

3.47 

4.34 

0.9889 

6.64 

8.27 

8 

0.63 

0.79 

8 

3.53 

4.42 

8 

6.71 

8.36 

7 

0.68 

0.86 

7 

3.59 

4.49 

7 

6.78 

8.45 

6 

0.74 

0.93 

6 

3.65 

4.56 

6 

6.86 

8.54 

6 

0.79 

0.99 

5 

3.71 

4.63 

5 

6.93 

8.63 

4 

0.84 

1.06 

4 

3.76 

4.71 

4 

7.00 

8.72 

3 

0.89 

1.13 

8 

3.82 

4.78 

3 

7.07 

8.80 

2 

0.95 

1.19 

2 

3.88 

4.85 

2 

7.13 

8.88 

1 

1.00 

1.26 

1 

3.94 

4.93 

1 

7.20 

8.96 

0 

1.06 

1.34 

0 

4.00 

5.00 

0 

7.27 

9.04 

0.9979 

1.12 

1.42 

0.9929 

4.06 

5.08 

0.9879 

7.33 

9.13 

8 

1.19 

1.49 

8 

4.12 

5.16 

8 

7.40 

9.21 

7 

1.25 

1.57 

7 

4.19 

5.24 

7 

7.47 

9.29 

6 

1.31 

1.65 

6 

4.25 

5.32 

6 

7.63 

9.37 

5 

1.37 

1.73 

6 

4.31 

5.39 

6 

7.60 

9.46 

4 

1.44 

1.81 

4 

4.37 

6.47 

4 

7.67 

9.54 

3 

1.50 

1.88 

3 

4.44 

5.55 

3 

7.73 

9.62 

2 

1.56 

1.96 

2 

4.50 

6.63 

2 

7.80 

9.70 

1 

1.62 

2.04 

1 

4.56 

5.71 

1 

7.87 

9.78 

0 

1.69 

2.12 

0 

4.62 

5.78 

0 

7.93 

9.86 

0.9969 

1.75 

2.20 

0.9919 

4.69 

5.86 

0.9869 

8.00 

9.95 

8 

1.81 

2.27 

8 

4.75 

5.94 

8 

8.07 

10.03 

7 

1.87 

2.35 

7 

4.81 

6.02 

7 

8.14 

10.12 

6 

1.94 

2.43 

6 

4.87 

6.10 

6 

8.21 

10.21 

5 

2.00 

2.51 

5 

4.94 

6.17 

5 

8.29 

10.30 

4 

2.06 

2.58 

4 

5.00 

6.24 

4 

8.36 

10.38 

3 

2.11 

2.62 

3 

5.06 

6.32 

3 

8.43 

10.47 

2 

2.17 

2.72 

2 

5.12 

6.40 

2 

8.50 

10.56 

1 

2.22 

2.79 

1 

5.19 

6.48 

1 

8.57 

10.65 

0 

2.28 

2.86 

0 

5.25 

6.55 

0 

8.64 

10.73 

0.9959 

2.33 

2.93 

0.9909 

5.31 

6.63 

0.9859 

8.71 

10.82 

8 

2.39 

3.00 

8 

5.37 

6.71 

8 

8.79 

10.91 

7 

2.44 

3.07 

7 

5.44 

6.78 

7 

8.86 

11.00 

6 

2.50 

3.14 

6 

5.50 

6.86 

6 

8.93 

11.08 

5 

2.56 

3.21 

5 

5.56 

6.94 

5 

9.00 

11.17 

4 

2.61 

3.28 

4 

5.62 

7.01 

4 

9.07 

11.26 

3 

2.67 

3.35 

3 

5.69 

7.09 

3 

9.14 

11.35 

2 

2.72 

3.42 

2 

5.75 

7.17 

2 

9.21 

11.44 

1 

2.78 

3.49 

1 

5.81 

7.25 

1 

9.29 

11.52 

0 

2.83 

3.65 

0 

5.87 

7.32 

0 

9.36 

11.61 

580 


APPENDIX. 


Percentage  of  Alcohol  by  Weight  and  by  Volume  from  the  Specific  Gravity 
(at  15.5°  C.),  by  Otto  Hehner.— Continued. 


Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

0.9849 

9.43 

11.70 

0.9799 

13.23 

16.33 

0.9749 

17.33 

21.29 

8 

9.50 

11.79 

8 

13.31 

16.43 

8 

17.42 

21.39 

7 

9.57 

11.87 

7 

13.38 

16.52 

7 

17.50 

21.49 

6 

9.64 

11.96 

6 

13.46 

16.61 

6 

17.58 

21.59 

5 

9.71 

12.05 

5 

13.54 

16.70 

5 

17.67 

21.69 

4 

9.79 

12.13 

4 

13.62 

16.80 

4 

17.75 

21.79 

3 

9.86 

12.22 

3 

13:69 

16.89 

3 

17.83 

21.89 

2 

9.93 

12.31 

2 

13.77 

16.98 

2 

17.92 

21.99 

1 

10.00 

12.40 

1 

13.85 

17.08 

1 

18.00 

22.09 

0 

10.08 

12.49 

0 

13.92 

17.17 

0 

18.08 

22.18 

0.9839 

10.15 

12.58 

0.9789 

14.00 

17.26 

0.9739 

18.15 

22.27 

8 

10.23 

12.68 

8 

14.09 

17.37 

8 

18.23 

22.36 

7 

10.31 

12.77 

7 

14.18 

17.48 

7 

18.31 

22.46 

6 

10.38 

12.87 

6 

14.27 

17.59 

6 

18.38 

22.o6 

5 

10.46 

12.96 

5 

14.36 

17.70 

5 

18.46 

22.64 

4 

10.54 

13.05 

4 

14.45 

17.81 

4 

18.54 

22.73 

3 

10.62 

13.15 

3 

14.55 

17.92 

3 

18.62 

22.82 

2 

10.69 

13.24 

2 

14.64 

18.03 

2 

18.69 

22.92 

1 

10.77 

13.34 

1 

14.73 

18.14 

1 

18.77 

23.01 

0 

10.85 

13.43 

0 

14.82 

18.25 

0 

18.85 

23.10 

0.9829 

10.92 

13.52 

0.9779 

14.90 

18.36 

0.9729 

18.92 

23.19 

8 

11.00 

13.62 

8 

15.00 

18.48 

8 

19.00 

23.28 

7 

11.08 

13.71 

7 

15.08 

18.58 

7 

19.08 

23.38 

6 

11.15 

13.81 

6 

15.17 

18.68 

6 

19.17 

23.48 

5 

11.23 

13.90 

5 

15.25 

18.78 

5 

19.25 

23.^8 

4 

11.31 

13.99 

4 

15.33 

18.88 

4 

19.33 

23.68 

3 

11.38 

14.09 

3 

15.42 

18.98 

3 

19.42 

23.78 

2 

11.46 

14.18 

2 

15.50 

19.08 

2 

19.50 

23.88 

1 

11.54 

14.27 

1 

15.58 

19.18 

1 

19.58 

23.98 

0 

11.62 

14.37 

0 

15.67 

19.28 

0 

19.67 

24.08 

0.9819 

11.69 

14.46 

0.9769 

15.75 

19.39 

0.9719 

19.75 

24.18 

8 

11.77 

14.56 

8 

15.83 

19.49 

8 

19.83 

24.28 

7 

11.85 

14.65 

7 

15.92 

19.59 

7 

19.92 

24.38 

6 

11.92 

14.74 

6 

16.00 

19.68 

6 

20.00 

24.48 

5 

12.00 

14.84 

5 

16.08 

19.78 

5 

20.08 

24.58 

4 

12.08 

14.93 

4 

16.15 

19.87 

4 

20.17 

24.68 

3 

12.15 

15.02 

3 

16.23 

19.96 

3 

20.25 

24.78 

2 

12.23 

15.12 

2 

16.31 

20.06 

2 

20.33 

24.88 

1 

12.31 

15.21 

1 

16.38 

20.15 

1 

20.42 

24.98 

0 

12.38 

15.30 

0 

16.46 

20.24 

0 

20.50 

25.07 

0.9809 

12.46 

15.40 

0.9759 

16.54 

20.33 

0.9709 

20.58 

25.17 

8 

12.54 

15.49 

8 

16.62 

20.43 

8 

20.67 

25.27 

7 

12.62 

15.58 

7 

16.69 

20.52 

7 

20.75 

25.37 

6 

12.69 

15.68 

6 

16.77 

20.61 

6 

20.83 

25.47 

6 

12.77 

15.77 

5 

16.85 

20.71 

5 

20.92 

25.57 

4 

12.85 

15.86 

4 

16.92 

20.80 

4 

21.00 

25.67 

3 

12.92 

15.96 

3 

17.00 

20.89 

3 

21.08 

25.76 

2 

13.00 

16.05 

2 

17.08 

i'0.99 

2 

21.15 

25.86 

1 

13.08 

16.15 

1 

17.17 

21.09 

1 

21.23 

25.95 

0 

13.15 

16.24 

0 

17-25 

21.19 

0 

21.31 

26.04 

- 

APPENDIX. 


581 


Percentage  of  Alcohol  by  Weight  and  by  Volume  from  the  Specific  Gravity 
(at  15.5°  C.\  by  Otto  Hehner. — Continued. 


Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

0.9699 

21.38 

26.13 

0.9649 

25.21 

30.65 

0.9599 

28.62 

34.61 

8 

21.46 

26.22 

8 

25.29 

30.73 

8 

28.69 

34.69 

7 

21.54 

26.31 

7 

25.36 

30.82 

7 

28.75 

34.76 

6 

21.62 

26.40 

6 

25.43 

30.90 

6 

28.81 

34.83 

5 

21.69 

26.49 

5 

26.50 

30.98 

5 

28.87 

34.  9U 

4 

21.77 

26.58 

4 

25.57 

31.07 

4 

28.94 

34.97 

3 

21.85 

26.67 

3 

25.64 

31.15 

3 

29.00 

35.05 

2 

21.92 

26.77 

2 

25.71 

31.23 

2 

29.07 

35.12 

1 

22.00 

26.86 

1 

25.79 

31.32 

1 

29.13 

35.20 

0 

22.08 

26.95 

0 

25.86 

31.40 

0 

29.20 

35.28 

0.9689 

22.15 

27.04 

0.9639 

25.93 

31.48 

0.9589 

29.27 

35.35 

8 

22.23 

27.13 

8 

26.00 

31.57 

8 

29.33 

35.43 

7 

22.31 

27.22 

7 

26.07 

31.65 

7 

29.40 

35.51 

6 

22.38 

27.31 

6 

26.13 

31.72 

6 

29.47 

35.58 

5 

22.46 

27.40 

6 

26.20 

31.80 

5 

29.53 

35.66 

4 

22.54 

27.49 

4 

26.27 

31.88 

4 

29.60 

35.74 

3 

22.62 

27.59 

3 

26.33 

31.96 

3 

29.67 

35.81 

2 

22.69 

27.68 

2 

26.40 

32.03 

2 

29.73 

35.89 

1 

22.77 

27.77 

1 

26.47 

32.11 

1 

29.80 

35.97 

0 

22.85 

27.86 

0 

26.53 

32.19 

0 

29.87 

36.04 

0.9679 

22.92 

27.95 

0.9629 

26.60 

32.27 

0.9579 

29.93 

36.12 

8 

23.00 

28.04 

8 

26.67 

32.34 

8 

30.00 

30.20 

7 

23.08 

28.13 

7 

26.73 

32.42 

7 

30.06 

36.26 

6 

'/3.15 

28.22 

6 

26.80 

32.50 

6 

30.11 

36.32 

6 

23.23 

28.31 

5 

26.87 

32.58 

5 

30.17 

36.39 

4 

23.31 

28.41 

4 

26.93 

32.65 

4 

30.22 

36.45 

3 

23.38 

28.50 

3 

27.00 

32.73 

3 

30.28 

36.51 

2 

23.46 

28.59 

2 

27.07 

32.81 

2 

30.33 

36.57 

1 

23.54 

28.68 

1 

27.14 

32.90 

1 

30.39 

36.64 

0 

23.62 

28.77 

0 

27.21 

32.98 

0 

30.44 

36.70 

0.9669 

23.69 

28.86 

0.9619 

27.29 

33.06 

0.9569 

30.50 

36.76 

8 

23.77 

28.95 

8 

27.36 

33.15 

8 

30.56 

36.83 

7 

23.85 

29.04 

7 

27.43 

33.23 

7 

30.61 

36.89 

6 

23.92 

29.13 

6 

27.50 

33.31 

6 

30.67 

36.95 

6 

24.00 

29.22 

6 

27.57 

33.39 

5 

30.72 

37.02 

4 

24.08 

29.31 

4 

27.64 

33.48 

4 

30.78 

37.08 

3 

24.15 

29.40 

3 

27.71 

33.56 

3 

30.83 

37.14 

2 

24.23 

29.49 

2 

27.79 

33.64 

2 

30.89 

37.20 

1 

24.31 

29.58 

1 

27.86 

33.73 

1 

30.94 

37.27 

0 

24.38 

29.67 

0 

27.93 

33.81 

0 

31.00 

37.34 

0.9659 

24.46 

29.76 

0.9609 

28.00 

33.89 

0.9559 

31.06 

37.41 

8 

24.54 

29.86 

8 

28.06 

33.97 

8 

31.12 

37.48 

7 

24.62 

29.95 

7 

28.12 

34.04 

7 

31.19 

37.55 

6 

24.69 

30.04 

6 

28.19 

34.11 

6 

31.25 

37.62 

6 

24.77 

30.13 

5 

28.25 

34.18 

5 

31.31 

37.69 

4 

24.85 

30.22 

4 

28.31 

34.25 

4 

31.37 

37.76 

3 

24.92 

30.31 

3 

28.37 

34.33 

3 

31.44 

37.83 

2 

25.00 

30.40 

2 

28.44 

34.40 

2 

31.50 

37.90 

1 

25.07 

30.48 

1 

28.50 

34.47 

1 

31.56 

37.97 

0 

25.14 

30.57 

0 

28.56 

34.54 

0 

31.62 

38.04 

582 


APPENDIX. 


Percentage  of  Alcohol  by  Weight  and  by  Volume  from  the  Specific  Gravity 
(at  15.5°  C.),  by  Otto  Hehner.— Continued. 


Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

0.9549 

31.G9 

3S.11 

0.9499 

34.57 

41.37 

0.9449 

37.17 

44.24 

8 

31.75 

38.18 

8 

34.62 

41.42 

8 

37.22 

44.30 

7 

31.81 

38.25 

7 

34.67 

41.48 

7 

37.28 

44.36 

6 

31.87 

38.33 

6 

34.71 

41.53 

6 

37.33 

44.43 

5 

31.94 

38.40 

5 

34.76 

41.58 

5 

37.39 

44.49 

4 

32.00 

38.47 

4 

34.81 

41.63 

4 

37.44 

44.55 

3 

32.06 

38.53 

3 

34.86 

41.69 

3 

37.50 

44.61 

2 

32.12 

38.60 

2 

34.90 

41.74 

2 

37.56 

44.67 

1 

32.19 

38.68 

1 

34.95 

41.79 

1 

37.61 

44.73 

0 

32.25 

38.75 

0 

35.00 

41.84 

0 

37.67 

44.79 

0.9539 

32.31 

38.82 

0.9489 

35.05 

41.90 

0.9439 

37.72 

44.86 

8 

32.37 

38.89 

8 

35.10 

41.95 

8 

37.78 

44.92 

7 

32.44 

38.96 

7 

35.15 

42.01 

7 

37.83 

44.98 

6 

32.50 

39.04 

6 

35.20 

42.06 

6 

37.89 

45.04 

5 

32.56 

39.11 

5 

35.25 

42.12 

5 

37.94 

45.10 

4 

32.62 

39.18 

4 

35.30 

42.17 

4 

38.00 

45.16 

3 

32.69 

39.25 

3 

35.35 

42.23 

3 

38.06 

45.22 

2 

32.75 

39.32 

2 

35.40 

42.29 

2 

38.11 

45.28 

1 

32.81 

39.40 

1 

35.45 

42.34 

1 

38.17 

45.34 

0 

32.87 

39.47 

0 

35.50 

42.40 

0 

38.22 

45.41 

0.9529 

32.94 

39.54 

0.9479 

35.55 

42.45 

0.9429 

38.28 

45.47 

8 

33.00 

39.61 

8 

35.60 

42.51 

8 

38.33 

45.53 

7 

33.06 

39.68 

7 

35.65 

42.56 

7 

38.39 

45.59 

6 

33.12 

39.74 

6 

35.70 

42.62 

6 

38.44 

45.65 

5 

33.18 

39.81 

5 

35.75 

42.67 

6 

38.50 

45.71 

4 

33.24 

39.87 

4 

35.80 

42.73 

4 

38.56 

45.77 

3 

33.29 

39.94 

3 

35.85 

42.78 

3 

38.61 

45.83 

2 

33.35 

40.01 

2 

35.90 

42.84 

2 

38.67 

45.89 

1 

33.41 

40.07 

1 

35.95 

42.89 

1 

38.72 

45.95 

0 

33.47 

40.14 

0 

36.00 

42.95 

0 

38.78 

46.02 

0.9519 

33.53 

40.20 

0.9469 

36.06 

43.01 

0.9419 

38.83 

46.08 

8 

33.59 

40.27 

8 

36.11 

43.07 

8 

38.89 

46.14 

7 

33.65 

40.34 

7 

36.17 

43.13 

7 

38.94 

46.20 

6 

33.71 

40.40 

6 

36.22 

43.19 

6 

39.00 

46.26 

5 

33.76 

40.47 

5 

36.28 

43.26 

5 

39.05 

46.32 

4 

33.82 

40.53 

4 

36.33 

43.32 

4 

39.10 

46.37 

3 

33.88 

40.60 

3 

36.39 

43.38 

3 

39.15 

46.42 

2 

33.94 

40.67 

2 

36.44 

43.44 

2 

39.20 

46.48 

1 

34.00 

40.74 

1 

36.50 

43.50 

1 

39.25 

46.53 

0 

34.05 

40.79 

0 

36.56 

43.56 

0 

39.30 

46.59 

0.9509 

34.10 

40.84 

0.9459 

36.61 

43.63 

0.9409 

39.35 

46.64 

8 

34.14 

40.90 

8 

36.67 

43.69 

8 

39.40 

46.70 

7 

34.19 

40.95 

7 

36.72 

43.75 

7 

39.45 

46.75 

6 

34.24 

41.00 

6 

36.78 

43.81 

6 

39.50 

46.80 

5 

34.29 

41.05 

5 

36.83 

43.87 

5 

39.55 

46.86 

4 

34.33 

41.11 

4 

36.89 

43.93 

4 

39.60 

46.91 

3 

34.38 

41.16 

3 

36.94 

44.00 

3 

39.65 

46.97 

2 

34.43 

41.21 

2 

37.00 

44.06 

2 

39.70 

47.02 

1 

34.48 

41.26 

1 

37.06 

44.12 

1 

39.75 

47.08 

0 

34.52 

41.32 

0 

37.11 

44.18 

0 

39.80 

47.13 

APPENDIX. 


583 


Percentage  of  Alcohol  by  Weight  and  by  Volume  from  the  Specific  Gravity 
(at  15.5°  C.},  by  Otto  Hehner.— Continued. 


Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

0.9399 

39.85 

47.18 

0.9349 

42.33 

49.86 

0.9299 

44.68 

52.34 

8 

39.90 

47.24 

8 

42.38 

49.91 

.   8 

44.73 

52.39 

7 

3995 

47.29 

7 

42.43 

49.96 

7 

44.77 

52.44 

6 

40.00 

47.35 

6 

42.48 

50.01 

6 

44.82 

52.48 

5 

40.05 

47.40 

5 

42.52 

50.06 

5 

44.86 

52.53 

4 

40.10 

47.45 

4 

42.57 

50.11 

4 

44.91 

52.58 

3 

40.15 

47.51 

3 

42.62 

50.16 

3 

44.96 

52.63 

2 

40.20 

47.56 

2 

42.67 

50.21 

2 

45.00 

52.68 

1 

40.25 

47.62 

1 

42.71 

50.26 

1 

45.05 

52.72 

0 

40.30 

47.67 

0 

42.76 

50.31 

0 

45.09 

52.77 

0.9389 

40.35 

47.72 

0.9339 

42.81 

50.37 

0.9280 

45.55 

53.24 

8 

40.40 

47.78 

8 

42.86 

50.42 

70 

46.00 

53.72 

7 

40.45 

47.83 

7 

42.90 

50.47 

60 

46.46 

54.19 

6 

40.50 

47.89 

6 

42.95 

50.52 

50 

46.91 

54.66 

5 

40.55 

47.94 

5 

43.00 

50.57 

40 

47.36 

55.13 

4 

40.60 

47.99 

4 

43.05 

50.62 

30 

47.82 

55.60 

3 

40.65 

48.05 

3 

43.10 

50.67 

20 

48.27 

56.07 

2 

40.70 

48.10 

2 

43.14 

50.72 

10 

48.73 

56.54 

1 

40.75 

48.16 

1 

43.19 

50.77 

00 

49.16 

56.98 

0 

40.80 

48.21 

0 

43.24 

50.82 

0.9379 

40.85 

48.26 

0.9329 

43.29 

50.87 

0.9190 

49.64 

57.45 

8 

40.90 

48.32 

8 

43.33 

50.92 

80 

50.09 

57.92 

7 

40.95 

48.37 

7 

43.39 

50.97 

70 

60.52 

58.36 

6 

41.00 

48.43 

6 

43.43 

51.02 

60 

50.96 

58.80 

6 

41.05 

48.48 

6 

43.48 

51.07 

60 

51  -38 

59.22 

4 

41.10 

48.54 

4 

43.52 

51.12 

40 

51.79 

59.63 

3 

41.15 

48.59 

3 

43.57 

51.17 

30 

52.23 

60.07 

2 

41.20 

48.64 

2 

43.62 

51.22 

20 

52.58 

60.52 

1 

41.25 

48.70 

1 

43.67 

51.27 

10 

53.13 

60.97 

0 

41.30 

48.75 

0 

43.71 

51.32 

00 

53.57 

61.40 

0.9369 

41.35 

48.80 

0.9319 

43.76 

51.38 

0.9090 

54.00 

61.84 

8 

41.40 

48.86 

8 

43.81 

51.43 

80 

54.48 

62.31 

7 

41.45 

48.91 

7 

43.86 

51.48 

70 

54.96 

62.79 

6 

41.50 

48.97 

6 

43.90 

51.53 

60 

55.41 

63.24 

5 

41.55 

49.02 

5 

43.95 

51.58 

60 

55.86 

63.69 

4 

41.60 

49.07 

4 

44.00 

51.63 

40 

56.32 

64.14 

3 

41.65 

49.13 

3 

44.05 

51.68 

30 

56.77 

64.58 

2 

41.70 

49.18 

2 

44.09 

51.72 

20 

57.21 

65.01 

1 

41.75 

49.23 

1 

44.14 

51.77 

10 

57.63 

65.41 

0 

41.80 

49.29 

0 

44.18 

61.82 

00 

58.05 

65.81 

0.9359 

41.85 

49.34 

0.9309 

44.23 

51.87 

0.8990 

58.50 

66.25 

8 

41.90 

49.40 

8 

44.27 

51.91 

80 

58.95 

66.69 

7 

41.95 

49.45 

7 

44.32 

51.96 

70 

59.39 

67.11 

6 

42.00 

49.50 

6 

44.36 

52.01 

60 

59.83 

67.53 

5 

42.05 

49.55 

5 

44.41 

52.06 

50 

60.26 

67.93 

4 

42.10 

49.61 

4 

44.46 

52.10 

40 

60.67 

68.33 

3 

42.14 

49.66 

3 

44.50 

52.15 

30 

61.08 

68.72 

2 

42.19 

49.71 

2 

44.55 

52.20 

20 

61.50 

69.11 

1 

42.24 

49.76 

1 

44.59 

52.25 

10 

61.92 

69.50 

0 

42.29 

49.81 

0 

44.64 

52.29 

00 

62.36 

69.92 

584 


APPENDIX. 


Percentage  of  Alcohol  by  Weight  and  by  Volume  from  the  Specific  Gravity 
(at  15.5°  C.\  by  Otto  Hehner. — Continued. 


Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcr  ho:  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

Specific 
gravity  at 
15.5°  C. 

Percent- 
age of 
absolute 
alcohol  by 
weight. 

Percent- 
age of 
absolute 
alcohol  by 
volume. 

0.8800 

62.82 

70.35 

40 

77.71 

83.60 

0.8190 

91.36 

94.26 

80 

63.26 

70.77 

30 

78.12 

83.94 

80 

91.71 

94.51 

70 

63.70 

71.17 

20 

78.52 

84.27 

70 

92.07 

94.76 

60 

64.13 

71.58 

10 

78.92 

84.60 

60 

92.44 

95.03 

50 

64.57 

71.98 

00 

79.32 

84.93 

50 

92.81 

95.29 

40 

65.00 

72.38 

40 

93.18 

95.55 

30 

65.42 

72.77 

0.8490 

79.72 

85.26 

30 

93.55 

95.82 

20 

65.83 

73.15 

80 

80.13 

85.59 

20 

93.92 

96.08 

10 

66.26 

73.54 

70 

80.54 

85.94 

10 

94.28 

96.32 

00 

66.70 

73.93 

60 

80.96 

86.28 

00 

94.62 

96.55 

50 

81.36 

86.61 

0.8790 

67.13 

74.33 

40 

81.76 

86.93 

0.8090 

94.97 

96.78 

80 

67.54 

74.70 

30 

82.15 

87.24 

80 

95.32 

97.02 

70 

67.96 

75.08 

20 

82.54 

87.55 

70 

95.68 

97.27 

60 

68.38 

75.45 

10 

82.92 

87.85 

60 

96.03 

97.51 

60 

68.79 

75.83 

00 

83.31 

88.16 

50 

96.37 

97.73 

40 

69.21 

76.20 

40 

96.70 

97.94 

80 

69.63 

76.57 

0.8390 

83.69 

88.46 

30 

97.03 

98.16 

20 

70.04 

76.94 

80 

84.08 

88.76 

20 

97.37 

98.37 

10 

70.44 

77.29 

70 

84.48 

89.08 

10 

97.70 

98.59 

00 

70.84 

77.64 

60 

84.88 

89.39 

00 

98.03 

98.80 

50 

85.27 

89.70 

0.8690 

71.25 

78.00 

40 

85.65 

89.99 

0.7990 

98.34 

98.98 

80 

71.67 

78.36 

30 

86.04 

90.29 

80 

98.66 

99.16 

70 

72.09 

78.73 

20 

86.42 

90.58 

70 

98.97 

99.35 

60 

72.52 

79.12 

10 

86.81 

90.88 

60 

99.29 

99.55 

50 

72.96 

79.50 

00 

87.19 

91.17 

50 

99.61 

99.75 

40 

73.38 

79.86 

40 

99.94 

99.96 

30 

73.79 

80.22 

0.8290 

87.58 

91.46 

20 

74.23 

80.60 

80 

87.96 

91.75 

0.7939 

99.97 

99.98 

10 

74.68 

81.00 

70 

88.36 

92.05 

Absolute 

Alcohol. 

00 

75.14 

81.40 

60 

88.76 

92.36 

0.7938 

100.00 

100.00 

50 

89.16 

92.66 

0.8590 

75.59 

81.80 

40 

89.54 

92.94 

80 

76.04 

82.19 

30 

89.92 

93.23 

70 

76.46 

82.54 

20 

90.29 

93.49 

60 

76.88 

82.90 

10 

90.64 

93.75 

50 

77.29 

83.25 

00 

91.00 

94.00 

APPENDIX. 


585 


V.    Physical  and  Chemical  Constants  of  Fixed  Oils  and  Pats. 

(FROM  LEWKOWITSCH  AND  OTHER  AUTHORITIES.) 


Specific  gravity 
at  15°C. 

Specific 
gravity 
at  100°C. 

Melting-point. 
C. 

Solidifying-point. 
C. 

Linseed  oil     

0.931-0.938 

0.880 

_16°to—  26° 

—16° 

Hemp-seed  oil  .... 

0.925-0.931 

—27° 

Walnut  oil        .... 

0.925-0.926 

0.871 

—27° 

Poppy-seed  oil  .   . 

0924-0.927 

0873 

—18° 

Sunflower  oil 

0  924-0  926 

0919 

—17° 

Fir-seed  oil       .... 

0.925-0.928 

—27°  to  —30° 

Maize  oil     

0.921-0.926 

—10°  to  —15° 

Cotton-seed  oil  .   . 

0.922-0.930 

0.867 

12° 

Sesame  oil  

0.923-0.924 

0.871 

—  5° 

Rape-seed  oil    .... 

0.914-0.91  7 

0.863 

—  2°  to—  103 

Black  mustard  oil    .   • 

0.916-0.920 

—17.5° 

Croton  oil  . 

0.942-0.955 

—16° 

Castor  oil 

0  960-0  966 

0910 

—  12°  to  —18° 

Apricot-kernel  oil 

0  915-0  919 

—14° 

Almond  oil    

0.915-0.920 

—10°  to  —20° 

Peanut  (arachis)  oil 

0.916-0.920 

0.867 

—  30  to  _7o 

Olive  oil  

0.914-0.917 

0.862 

2° 

Menhaden  oil    .    . 

0  927-0  933 

—4° 

0  922-0  927 

0874 

0°  to  —10° 

Seal  oil    

0.924-0.929 

0.873 

3° 

Whale  oil   

0.920-0.930 

0.872 

—2° 

Dolphin  oil 

0.917-0.918 

5°  to  —3° 

Porpoise  oil              .   . 

0926 

0.871 

—16° 

Neat's-foot  oil   .... 

0.914-0.916 

0.861 

0°  to  1.5° 

Cotton-seed  stearine    . 
Palm  oil  

0.919-0.923 
0.921-0.925 

0.867 
0.856 

40° 

27°  to  42° 

31°  to  32.5° 

Cacao  butter  

0.950-0.952 

0.858 

30°  to  33° 

25°  to  26° 

Cocoa-nut  oil  

0.925-0.926 

0.873 

20°  to  26° 

16°  to  20° 

Myrtle  wax    

0.995 

0.875 

40°  to  44° 

39°  to  43° 

Japan  wax  

0.970-0.980 

0.875 

51°  to  54.5° 

46° 

Lard     

0.931-0.938 

0.861 

41°  to  46° 

29° 

Bone  fat  

0.914-0.916 

21°  to  22° 

15°  to  17° 

Tallow     

0.943-0.952 

0.860 

42°  to  46° 

35°  to  37° 

Butter  fat    , 

0.927-0.936 

0.866 

29.5°  to  33° 

19°  to  20° 

Oleomargarine  .   . 

0.924-0.930 

0.859 

Sperm  oil    .   . 

0.875-0.884 

0.833 

—25° 

Bottle-nose  oil 

0.879-0.880 

0.827 

Carnauba  wax  .... 
Wool-fat  

0.990-0.999 
0.973 

0.842 
0.901 

84°  to  85° 
39°  to  42° 

80°  to  81° 
30°  to  30.2° 

Beeswax   

0.958-0.969 

0.822 

62°  to  64° 

60.5°  to  62° 

Spermaceti  

0.960 

0.812 

43.5°  to  49° 

43.4°  to  44.2° 

Chinese  wax   

0.970 

0.810 

80.5°  to  81° 

80.5°  to  81° 

Tun  <*  (Chinese  wood  oil) 

0.936-0.942 

below  —17° 

Soya-bean  oil 

0  924-0  927 

8°  to  15° 

586 


APPENDIX. 


V.   Physical  and  Chemical  Constants  of  Fixed  Oils  and 

Fats. — Continued. 

(FROM  LEWKOWITSCH  AND  OTHER  AUTHORITIES.) 


Saponiflcation 
value. 

Maumen6 
test. 

Iodine  value. 

Hehner 
value. 

Reichert 
value. 

Linseed  oil  

190-195 

104°-111° 

175-190 

Hemp-seed  oil    .... 

190-193 

95°-96° 

148 

Walnut  oil   

195 

96°-101° 

144_147 

Poppy-seed  oil   .... 
Sunflower  oil  

195 
193-194 

86°-88° 
72°-75° 

134-141 
120-129 

95.38 
95 

Fir-seed  oil  

191.3 

98°-99° 

118.9-120 

Maize  oil  

188-193 

56°-60.5° 

117-125 

89-95.7 

2.5 

Cotton-seed  oil  .   .   .   . 
Sesame  oil    

191-195 
189-193 

68°-77° 
64°-68° 

104-110 
105-109 

96-17 
95.8 

0.35 

Rape-seed  oil  

170-178 

51°-60° 

95-105 

95 

Black  mustard  oil  .   .   . 
Croton  oil    

174-174.6 
210.3-215 

430.440 

96°-110 
101.7-104 

95.05 
89 

13.5 

Castor  oil  

178-186 

46°_47° 

83.4-85.9 

1.4 

Apricot-kernel  oil  .   .  . 

192.2-193.1 

42.5°-46° 

100-107 

Almond  oil  

190.5-195.4 

51°-54° 

93-97 

96.2 

Peanut  (arachis)  oil  .   . 
Olive  oil    

190-197 
191-196 

45°-49° 
41.5°-45.5° 

85-98 
80.6-84.5 

95.86 
95.43 

0.3 

Menhaden  oil  

189.3-192 

123°-128° 

140-170 

1.2 

Cod-liver  oil    

182-187 

102°-103° 

154-180 

95.3 

Seal  oil  

190-196 

92° 

127-140 

94.2 

0.22 

Whale  oil  

188-193 

91°-92° 

110-136 

93.5 

2.04 

197.3 

99.5 

93.07 

5.6 

Dolphin  oil  j  jaw  QJI 

200 

32.8 

66.28 

65.92 

Porpoiseoill^yoj1- 

216-218.8 
253.7 

50° 

119.4 
49.6 

6841 

23.45 
65.8 

Neat's-foot  oil 

1943 

47°-48.5° 

69.3-70.4 

Cotton-seed  stearine   . 
Palm  oil          

194.6-195.1 
196.3-202 

48° 

88.7-92.8 
53-57 

96.3 
95.6 

0.5 

Cacao  butter  
Cocoa-nut  oil  

192.2-193.5 
250-253 

32-41 
8.5-9.3 

94.59 

88.6 

1.6 
3.7 

Myrtle  wax    
Japan  wax  

205.7-211.7 
220-222.4 

2.9 

4.2-8.5 

90.6 

Lard    

195.3-196.6 

27°-32° 

57-70 

96 

Bone  fat    

190.9 

46.3-49.6 

Tallow  

195-198 

36-47 

95.6 

0.25 

Butter  fat  

221.5-227 

26-35 

87.5 

28.78 

Oleomargarine    .... 

194-203.7 

55.3-60 

95-96 

2.6 

Sperm  oil  

132.5-147 

47°-51° 

84 

1.3 

Bottle-nose  oil    .... 
Carnauba  wax    .... 

126-134 
80-84 

41°-47° 

77.4-82 
13.5 

1.4 

Wool-fat   

98  2-102  4 

25-28 

Beeswax    

91-96 

8.3-11 

Spermaceti  

128 

Chinese  wax   

63 

Tung  (Chinese  wood  oil) 

193 

150-165 

Soya-bean  oil  

190.6-192.9 

59°-61° 

121-.3-124 

95.5 

INDEX. 


Abel  tester  for  oils,  40 
Absinthe,  253 
Acetate  of  alumina,  548 
Acetate  of   iron,   533,  548 
Acetates,   analysis   of,   395 
Acetic  acid  production,   391 

ferment,  266,  270 

Acetin  method  of  glycerine  analysis,  94 
Acetone,  394 

in  wood-spirit,   392 
Acetophenone,  448 
Achroodextrine,   187 
Acid  brown  G,  463 

dyes,  456,  471 

magenta,  457 

process   for   starch,   189 

violet,  412 

yellow,  461 
Acidity  of  beer,  223 

of   tan-liquors,   374 
Acridine,  454 

yellow,  465 

Adams'  method  for  fat  in  milk,  294 
Adjective  dyeing,  531 
Adulteration  of  beer,  223 
Adulteration  of  butter,  296 
Aerated  bread,   262 
After-fermentation  of  beer,  217 
Agalite,   321 
Agar-agar,  377 
Albertite,   18 

Albuminoids  in  milk,  294 
Alcohol  in  beer,  222 

tables  of  Hehner,  579 
Alcoholic  beverages,  manufacture  of,  239 

fermentation,  205,  208 
Ale,   218 

Aleurometer  of  Boland,  264 
Algin,  377 
Alizarin,  453,  466,  550 

black  S,  468,  551 

blue,  467 
S,    468 

bordeaux  B,  467 

cyanine  R,  467 

dyeing,  539 

green  S,  468 

indigo-blue  S,  468 

manufacture,  453 

maroon,  467 

on  cotton,  550 

orange,  467 

red,  467 

saphirol,  467 


Alizarin,  yellow,  462 
A,  468 
C,  468 
Alkali  blue,   457 

process    for    starch,    189 
Almond  oil,  54 
Alpaca  fibre,  344 
Alum  tawing,  366 

in  bread,   261,   265 
Alumina  mordants,  532 
Aluminum  acetate,   532 
Amaranth,  462 
Amber,   107 

malt,  209 

American  grades  of  benzol,  417 
Amidoazo  dyes,  463 
p-Amidobenzene-sulphonic    acid,    445 
Amine  dye-colors,  457 
Ammonia    liquor,    valuation   of,    428 

recovery  of,  from  gas-liquor,  413 
Ammoniacal  cochineal,  503,  507 
Amylodextrine,   187 
Analysis  of  dyes,  471 

of  fats,  scheme  for,  92 
Aniline,  441 

black,  458,  539 
dyeing,  539 

blue,   457 

hydrochloride,   441 

manufacture,  449 

red,  457 

rose,  458 

salt,  441 

still,  450 

sulphate,  441 
Animal  fibres,  bibliography  of,  353 

hide,  structure  of,  356 
Anim^,   107 
Anisette,  254 
Anisol  red,  462 
Annatto,  295,  493 
Anthracene,   422,  436,  453 

brown,  468 

oil,  421 

series,  436 

sulphonic  acid,  444 

yellow,  468 
Anthracite  black,  463 
Anthragallol,   468 
Anthranilic  acid,  466 
Anthrapurpurin,   467 
Anthraquinone,    448,    453 

sulphonic  acid,  445,  453 
Anthrarufine,  467 

"  Antichlor  "  in  paper-bleaching,  320 
Antimony  mordants,  533 
Application  of  artificial  colors  to  cotton, 
537 

587 


588 


INDEX. 


Appolt's  coke-oven,  405 
Arachis  oil,  56 
Archil,  491 

substitute,  461 
Ardent  spirits,  manufacture  of,  239 

raw  materials  of,  239 
Argols,  226,  234 
Arrack,  251 
Artificial  asphalts,  28 

butter,  284,  289 

camphor,  106 

coloring    matters,    bibliography    of, 
485 

dye-colors,  statistics  of,  486 

indigo,  465,  466 

rubber,  123 

silk,  333 

Asboth  method  for  starch,  199 
Ash  of  raw  sugars,  composition  of,  176 
Asphalt  paving  composition,  35 

residue  in  lubricating  oils,  45 

occurrence  of,   17 
Asphalts,  analysis  of,  47 

artificial,  28 

composition  of,  18 
Assouplissage,  350 
Atlas  powder,  84 
Auramine,  458,  538 
Aurantia,  459 
Aureosin,   459 
Aurin,  459 

Autoclave  process  for  fats,  64 
Avignon  berries,  493 
Azines,  458 
Azo  blue,  464,  538 

dye-colors,  461 

mauve,  464 
Azococcin,  2E,  462 

7B,  463 
Azolitmin,  496 
Azorubin  S,  462 
Azurine,  460 

B 

Babcock  method  for  fat  in  milk,  294 

Bacterial  fermentation,  204 

Bagasse,  170 

Bahia-wood,  488 

Baking,  chemistry  of,  261 

powders,  260 
Balata,   110 
Balling  sugar  degrees  and  Baume  scale, 

570 

Balsams,  107 
Bar-wood,  488 

Barlow's  high  pressure  kiers,  524 
Basic  dyes,  456,  471 
Bast  fibres,  302 
Bastards,  169 
Bastose,   303 
Bate,  use  of,  366 
Baume's  scale  for  liquids  heavier  than 

water,  567 
for  liquids  lighter  than  water, 

566 
Bavarian  thick-mash  process,  213 


"  Bayer's  acid,"  445 

Beating  machine  for  paper-pulp,  320 

Becchi's  test,  90 

"  Bee-hive  "  coke-ovens,  405 

Beer,  analysis  of,  221 

fall,  216 

ferment,  205 

production  in  the  United  States,  276 
Beeswax,  58 
Ben  oil,  55 
Benedictine,  254 
Benzal-chloride,  437 
Benzaldehyde,  448 

green,  457 
Benzene,  433 

disulphonic  acid,  444 

hydrocarbons,  433 

sulphonic  acid,  444 
Benzidine,  443 

dyes,  464 
Benzine  distillate,  24 

properties  of,  32 
Benzoaurine,  464 
Benzo-azimine,  538 
Benzoic  acid,  447,  452 

aldehyde,  448' 
Benzo-indigo-blue,  464 
Benzol,  tests  for,  424 
Benzophenone,  448 
Benzopurpurin,   464 
Benzo-trichloride,  437 
Benzyl  chloride,  437 
Bermudez   asphalt,    17 
Betaine,  169 
Biebrich  scarlet,  463 
Bichromate   of   potash,   533 

of  soda,  533 
Bismarck  brown,  463 
Bisulphite  process  for  wood-pulp,  312 
Bituminous  coal,  397 

shales,  28 
Bixin,  493 
Black  dyes,  recognition  of,  on  fibre,  484 

bread,   258 

iron  liquor,  548 

liquor   in  papermaking,   325 

seed  cotton,  304 
Blasting  gelatine,  85 
Blauholz,  495 
Bleached  flour,  261 
Bleached  lac,  108 
Bleaching  agents,  529 

dyeing,  and  textile  printing,  bibliog- 
raphy of,  557 

kiers,  524 

of  paper-pulp,  317 

of  wool,  347,  528 

processes,  522 
Block  coal,  399 
Bloom   in   petroleum   oils,   32 
Blotting-paper,  322 
Blown  oils,  81 

Blue  dyes,  recognition  of,  on  fibre,  481 
Bock-beer,  218 

Boettger's  test  for  vegetable  fibres,  360 
Boiled  oil,  80 


INDEX. 


"  Boiled-off "  liquid,  346,   349 

silk,  349 

Boiley's  blue,  509 
Boiling  of  linseed  oil,  113 
Bois  de  Br6sil,  488 

de  Campeche,  495 
Bone-black,  analysis  of,  179 

exhausted,  171 

filters   for   sugar,   150 

revivifying  of,  164 
Bone  fat,  59 

glue,  379,  380 
Bordeaux  B,  462 

G,  463 
Borneol,  106 

Bottom  fermentation,  205 
Brandy,   252 
Brasilein,  488 
Brasilin,  488,  505 
Brazil-wood,  488 
Bread,  adulteration  of,  265 

analyses  of,  262 

method  of  analysis  of,  267 
Brewer's  yeast,   259 
Brie  cheese,   290 
Briquettes  for  fuel,  423 
Brix     degrees     compared     with     Bailing 

scales,  570 
Bread-making,  257 
Brilliant  Congo  G,  464 

croce'in,  463 

green,  457 

ponceau,  4E,  462 
British  gum,   196 
Bromine  absorption  of  fats,  88 
a-Brom-naphthalene,  438 
Brown  acetate  of  lime,  391,  393 

coal,  398 

dyes,  recognition  of,  on  fibre,  483 

malt,  212 

Burmese  lacquer,  111 
Burning  naphtha,  417 
Butter,  289 

analysis  of,  296 

coloring  matter  of,  299 

fat,  56,  289 

manufacture  of,   281,   284 

yellow,  461 
Butterine,  284,  289 
Button:lac,   108 

By-product  coke-ovens,  405,  431 
Byerlite,  28 

c 

Cacao  butter,  55 
Cachou  de  Laval,  468 
Calcium  acetate,  391 
Caliatur-wood,  488 
California  wood,  488 
Calorisators,  or  juice-warmers,  152 
Camel's-hair  fibre,  344 
Camembert  cheese,  290 
Camphors,  104,  106 
Cam-wood,  488 
Candle  manufacture,  74 
Candle-making  materials,  76 


Cane-sugar,  bibliography  of,  182 
Cannel  coal,  398 
Caoutchouc,  108,  117,  122 

statistics  of,  133 
Capri   blue,   461 
Caramel  coloring,  194 

in  spirits,  256 
Carbazol  yellow,  464 
Carbolic  acid,  418,  426 
Carbonatation  process,  146,   156 
Carbonate   of   potash,   530 
Carbonizing  mixed  cotton  and  wool,  343 
Cardboard,  324 
Carded  wool,  350 

Carmichael  electrolytic  process,  320 
Carmine,  analyses  of,  508 

naphte,  46  i 

preparation  of,   503 

red,  491 

Carminic  acid,  491 
Carmosin,  462 
Carnauba  wax,  56 
Carthamic  acid,  490 
Carthamin,  490 
Casein  of  milk,  279 

preparations,  292 
Cashmere  wool,  343 
Casing-head  gas,   19 
Castile  soap,  69 
Castor  oil,  53 
Catechin,  497 
Catechu,  359,  497,  534 

extract,  359,  514 
Catechutannic  acid,  359,  497 
Caustic  soda,  530 
Celluloid,  330,  332 
Cellulose  nitrates,  327 

xanthogenate,   334 
Centigrade  and   Fahrenheit  scales,   562, 

563 

Centrifugals,   145 
Cerasine,  462 

Cereals,  composition  of,  186 
Ceresine,   27,   35 
Chamois  leather,  369,  371 
Champagnes,  231 

manufacture  of,  229 
Chaptalization  of  wines,  228 
Charcoal   from   wood,   394 
Chardonnet  process  for  artificial  silk,  334 
CTiar-kilns,    164 
Chartreuse,  254 
Cheddar  cheese,  290 
Cheese,  analysis  of,  299 

making,  286 

varieties  of,  290 
Chemic  blue,  509 
Chemical  wood-pulp,  312 
Chestnut-wood  in  tanning,  358 
Chicle,   110 
China-grass,   308 
Chinese  green,  497 

isinglass,   377 

lacquer,  111 

wax,  58 


590 


INDEX. 


Chinoline,  454 

Chipping  of  dyewoods,  497,  500 

Chloracetic  acid,  466 

Chloride  of  lime   bleaching,   525 

Chlorophyll,  496 

"  Chlor-ozone,"   529 

Chondrin,  375 

Chromatropes,  463 

Chrome  alum,  533 

tanning,  368 

"  Chroming  "  of  wool,  531 
Chromium  mordants,  533 
Chromogens,  456 
Chromophor  groups,  456 
Chrysamine,  464,  538 
Chrysaniline,  465 
Chrysene,  437 
Chrysoidine,  401 
Chrysophenine,  464,  538 
Chrysorhamnin,  493 
Cider  vinegar,  manufacture  of,  270 
Cineol,  106 

Cingalese  lacquer,  111 
Citral,   104 

Clark's  water  purification  process,  535 
Clayed  sugars,  167 
Cleansing  of  fibres,  522 
Clerget's  process  of  inversion,   174 
Cloth  brown,   464 

dyeing,   536 

red  G,  463 

Coal  distillation,  statistics  of,  431 
Coals,  composition  of,  398 
Coal-tar  colors  on  wool,  543 

diagram  of  distillation,  412 

dyes,  identification  of,  471 

fractions,  410 

pitch,  423,  428 

statistics,  432 

still,  408 
Coccerin,  491 
Cochineal,  491 

analysis,  515 

carmine,  491,  507 

dyeing,  542 

red  A,  462 

scarlet  2R,  461 
Cocoa-nut  fibre,  309 

oil,  55 

Cod-liver  oil,  57 
Coefficient    of    expansion    of    petroleum 

oils,  566 
Coerulein,  460 

S,  460 

Coffey  still,  246 
Cognac,  252 
Coir  fibre,  309 

Coke-oven  distillation  of  coal,  405 
Coking  coals,  397 
Cold  process  of  soap-making,  70 

test  for  oils,  43 

vulcanization   process,    117 
Collodion,  328,  329 
Cologne  glue,  380 
Colophony  resin,   105,    108 
Color  analysis  in  milk,  295 


Colorimetric  tests  for  oils,  46 
Coloring  for  paper-pulp,   321 

matter  in  wines,  238 

recognition  of,  in  paper,  327 
Colza  oil,  55 
Combed  wool,  350 
Combination  tanning,  368 
Commercial   indigo,   composition  of,  509 
Comparative  dye  trials,  469 
Comparison     of     Twaddle     scale     with 

rational  Banine"  scale,  569 
Composition  of  gas-liquor,  413 
Compressed  yeast,  259 
Compression  test  for  paraffin,  46 
Concrete  sugar,   167 
Condensed   milk,   281,   288 
Conditioning  of  wool,   342 

silk,    348 
Congo  Corinth  G,  464 

G  and  P,  464 

group  of  dyes,  464,  538 

red,  464 

yellow,  464 
Consumption     of    malt    liquors    in    the 

United  States,  277 
Copal,  157 

varnish,  114 
Coppee   coke-oven,   405 
Copper   mordants,   533 

nitrate,  533 

sulphate,  533 

wall  in  sugar  extraction,   141 
Copperas  vat,  506 
Cordials,   253 
Cordite,  85 
Coriin,  357 
Corn  oil,  55 

syrup,  195 
Cotton  bleaching,   523 

dveing,  535 

fibre,  303 

scarlet,  465 

seed  oil,  53 

products   from,   80 

statistics  of,  338 
Cow's  milk,  279 
Crackers,  26 

Cracking  of  petroleum,  20 
Cracklings  process  of  melting  fats,  60 
Crampton's  test  for  caramel,  256 
Cream  separators,  282 
Creme  de  menthe,  2'54 
Creosote,   394 

oil,  419,  427 

Creosoting  of  timber,  420 
Creydt's  method  for  raffmose,  178 
Crocein  orange,  462 

scarlet   3B,   463,   538 
Crop-madder^  490 
Crown   leather,   371 
Crude  petroleum,  analysis  of,  36 
Crystallized  grape-sugar,   192 
Cudbear,  491 
Cumidine  red,  462 

Cuprammonium     process     for    artificial 
silk,  334 


INDEX. 


591 


Curacoa,  254 
Curcuma,  493 
Curcumin,   493 
Curd  of  milk,  280 
Curing  of  logwood,  496 

sugar  crystals,  145 
Cut  soaps,  82 
Cutch,  497 

in  tanning,  359 
Cutting  of  dye-woods,  497 
Cyanine,  465 
Cyanosine,  460 
Cyclamine,  460 
Cylinder  oils,    32 
Cymogene,  31 

D 

Dammar  resin,  107 

Decoction  process  of  mashing,  212,  213 

Defren's  method,  175 

Defecation  of  sugar- juice,   141 

Degommage,  349 

Degraissage,  346,  350 

Degras,   370,   372 

Degreasing  of  wool,  346 

Delta-purpurin  5B,  464 

Demerara  crystals,  167 

Dephlegmators,  244 

Destructive  distillation,  bibliography  of, 

430 

of  coal,  397 
of  wood,  385 
theory  of,  385 
D6suintage,  346 
Dextrine,  analyses  of,  196 
manufacture  of,   194 
Dextropinene,   105 
Diagram  of  coal-tar  distillation,  412 

of  distillation  of  coal,  401 
Diamidoazobenzene  hydrochloride,  461 
Diamine  black,  464 
blue,  464 
brown,  464 
gold,  464 
green,  464 
scarlet,  464 
Diastase,  204,  208 
Diastatic   power  of  malt,  220 
Diazo-amido-benzene,  446 
Diazo-benzene  chloride,  446 
Diazo-benzene-sulphonic  acid,  447 
Diazo-compounds,   446 
Diazotizing,  455 
Dibrom-anthracene,  438 
Dichlor-anthracene,  438 
Diffusion   cells,   152 

process  in  extracting  sugar,  151 
Dimethylaniline,  441 

orange,  461 
Dimethyl  benzene  or  xylene,  435 

ketone,  448 
Di nitrobenzene,   396 
Dinitrocellulose,  328 
o-Dinitronaphthalene,  440 


/3-Dinitronaphthalene,  440 
Dinitrosoresorcin,   460 
Dinitrotoluenes,  440 
Dioxine,  460 
Diphenyl,  435 
Diphenylamine,  443 
blue,  457 
orange,  461 

Diphenyl-methane  dyes,  458 
Direct  printing  processes,  549,  546 
Discharges  in  calico-printing,  554,  555 
Diseases  of  wines,  226 
Distillation  of  essential  oils,   103 
of   fermented   mash,    244 
of  petroleum,  20,  22 
of  sawdust,  388 
of  wood,  387 
Distilled  spirit,  rectification  of,  249 

spirits,  production  of,  in  the  United 

States,   276 

Distiller's  residues,  255 
Distinctions  between  two  naphthols,  443 
between  artificial   and  natural   silk, 

337 
between  vegetable  and  animal  fibres, 

351 

Disulphonic  acids  of  /3-naphthol,  445 
Diterpenes,    104 
Divi-divi,   360 

Double-effect  vacuum-pans,   144 
Doubling,  249 
Dough,  preparation  of,  260 
Dry  wines,  231 
Dryers  for  oils,  80 
Drying  oils,  54 
Dunder,  244 

Dyed  fabrics,  examination  of,  474 
Dyeing  and  textile  printing,  bibliography 
of,  557 

processes,  534 

Dye-wood  extracts,  manufacture  of,  500 
Dye-woods,   curing  of,  498 
Dynamite,   79,   84,   532 

analysis  of,  95 
"  Dynamited  silk,"  545 
extraction  of,  501 


E 


Eau  de  vie  de  marc,  252 

Ebonite  or  hard  rubber,  123 

Ecru   silk,   349,   350 

Effervescing  wines,  manufacture  of,  229 

Eidam  cheese,  290 

Electrolytic  bleaching,  527 

Elution  process  for  molasses,  162 

Enamelled  leather,  371 

Enfleurage,  103 

Engine-sizing  for  paper,  321 

Engler  viscosimeter,  44 

Enzymes,   203,   204 

Eosins,  459,  537 

Equivalent   English   and  metric  weights 

and  measures,  562 
Erythrodextrine,  187 
Erythrosin,  459 


592 


INDEX. 


Erythrozym,  490 
Esparto,  313,  314 
Essential  oils,  adulteration  of,  124 

bibliography  of,  129 

classification   of,    104 

extraction  of,  103 

statistics  of,  131 
Ethyl  eosin,  459 

naphthalene,  435 
Eurhodines,  458 
Evrard  process,  60 
Examination  of  dyed  fabrics,  474 
Extract  determination  in  beer,  221 

wool,  351 
Extraction  of  oil  seeds  by  solvents,  62 


Factitious   brandy,   252 

vinegars,    271 
Fahrenheit  and   Centigrade   scales,   562, 

563 

Faints,   249 
Fast  brown,  463 
N,  462 
red  A,  462 

B,  462 

C,  462 

D,  462 
violet,  463 
yellow,  461 

Fastness  of  dyes  to  light,  469 

to  soaping,  469 

Fat    determination    in   milk,    294 
Fats  and  oils,  analysis  of,  85 
bibliography  of,  95 
statistics   of,    96 
Fatty  oils,  composition  of,  58 
Fehling's  solution,  preparation  of,  174 

use  of,   175 

Feldman's   ammonia   still,   414 
Fermentation,  bibliography  of,  272 

nature   of,   203 

of  dyewoods,  498 

of  grape  juice,  225 

of  mash  for  spirits,  242 

of  wort,  216 
Ferments,  soluble,  203 
Ferrous  acetate,  533 

sulphate,  533 

Fibre,  recognition  of,  in  papers,  325 
Fibroin,  346 

Fibro-vascular  bundles,  302 
"Fifty  per  cent,  benzol,"  416,  434 
Filled  soaps,   70 
Fire  test  of  oils,  39 
Fischer  viscosimeter,  44 
Fisetin,  492 
Fish-bladders,  377 

gelatine,  380 

Fixed  oils  and  fats,  physical  and  chem- 
ical   constants   of,    585,    586 
Flash-point  of  oils,  39 
Flavaniline,  465 
Flavine,   492,   503 
Flavopurpurin,  467 


Flax,  305 

statistics  of,  339 
Flour,   257 

adulterations  of,  265 

and  bread,  bibliography  of,  275 
Fluoranthene,  436 
Fluorene,  436 
Fluorescein,  453,  459 
Fluoride  of  antimony  and  potassium,  533 
Forcite,   84 
Formaldehyde    in   milk,    296 

in  tanning,  369 

Fortified   wines,   manufacture   of,   229 
Fourdrinier  machine  for  paper,  322 
Fractional  generation  of  coal-tar,  408 
Fromage  de  Brie,  290 
Fryer   concretor,   147 
Fuchsine,  457,   537 

S,  457 
Fuel  gas,  30 

oil,  34 

Fuller's   earth   for   oil    clarifying,   63 
Fusel   oil,   determination  of,   256 
Fustic,  492 
Fustin,  492 


Gaban-wood,  489 
Gallamine  blue,  461 
Gallanilic  indigo,  460 
Gallein,   460 
Gallic  acid,  447 
Gallipoli  oil,  80 
Gallisin,  187,  197 
Gallization  of  wines,  228 
Gallocyanine,  460 
Galloflavin,  468 
Gambier  in  tanning,  359 
Gambine,  460 
Gas  analysis,  429 

coals,   composition  of,   398 

liquor,  constituents  of,  413 

oils,  33 

purifiers,  403 

retort  distillation  of  coal,  401 

tar  and  coke-oven  tar,  408 
Gasolene,  31 
Gelatine,  379,  380 

dynamite,  85 
Gelbbeeren,   493 
Gilsonite,    17 
Gin,    253 

Glacial  acetic  acid,  391 
Glance  pitch,  17 
Gloucester  cheese,  290 
Glucose,  analyses  of,  195 

determination  of,  174 

manufacture  of,  190 

method  for  analysis  of,   199 

vinegar,  271 
Glue,   analysis  of,  381 

and  gelatine  manufacture,  375 

stock,  377 

Gluten  in  bread,  257 
Glutin,  375 


INDEX. 


593 


Glycerine  manufacture,  77 

in  wines,  236 

properties  of,  83 

refining  of,  77 

statistics  of,  102 
Golden  syrup,  169 
Graham's    method    for   glucose   analysis, 

201 

Grain  mash,  241 
Grape,  composition  of,  223 

sugar  and  glucose  statistics,  201 
manufacture  of,   190,   192 

varieties  of,  224 
Gray  acetate  of  lime,  393 
Green  dyes,  recognition  of,  on  fibre,  48 

hides,  357 

seed  cotton,  304 

syrup,  169 
Gruyfire  cheese,  290 
Guanaco  fibre,  343 
Guarancine,  490,  502 
Gum  arabic,  107 

resins,   107 
Gun-cotton,  327,   328 

analysis  of,  333 
Gutta-percha,   110,   119,   123 

statistics  of,  133 

vulcanization  of,  119 

H 

Haematein,   496,    511 
Hsematoxylin,    496 
"Half-stuff"  paper-pulp,  317 
Halogen   derivatives  of  benzene,   437 
Halphen's  test  for  cotton-seed  oil,  90 
Hand-made    paper,    321 
Hansen's  yeast  cultures,  207 
Hanus   method   for   iodine   figure,   90 
Hard  biscuit,  263 

fibre,  324 

rubber,  118 

soaps,  68 

water,  535 

Harness  leather,  365,  370 
Heat,   effect  of,   on  wood,   386 
Heavy  oil,  411,  419 
Hehner's   method,   297 
Helianthin,  461 
Heliotrope,  464 
Hemiterpenes,  104 
Hemlock  bark  in  tanning,  358 
Hemp  fibre,  306 
Hemp-seed  oil,  53 
Henequen  fibre,  308 
Hercules   powder,   84 
Hermite  bleaching  process,  319,  527 
Hessian  purple,  464 

violet,  464 

yellow,  464 
Heumann's  tester,  42 
Hexanitrate  of  cellulose,  327 
Hide  glue,  377,  380 
Hides,   varieties   of,   357 
High   and   low   heat,   effect   of,   on   coal, 
399,  400 

milling  process,  258 


Hofmann's  violets,  457 
Hollander  for  paper  stock,  316 
"  Hollands,"  253 

Hop  production,  statistics  of,  275 
Hops,   209,   210 

in  manufacture  of  beer,  215 
Horsechestnut-bark  in  tanning,  358 
Hiibl's  method,  89,  297 
Huile  tournante,  80 
Hydrated  soap,  68 
Hydrochloric  acid,  530 
Hydrogen  peroxide,  529 

bleaching,  528 

Hydrolysis  of  starch,  results  of,  187 
Hydrosulphite  vat  for  indigo,   536 


Identification  of  coal-tar  dyes,  471 
Illuminating  gas,  analysis  of,  429 

composition  of,  405 
Imitation  wines,  manufacture  of,  230 
Immedial  black,  468 

blue,  468 
Indamines,  460 
Indanthrene  X,  468 
Indian   lacquer,   111 
India-rubber,  108,  117,   122 
Indican,  494 
Indiglucin,  494 
Indigo,  493 

analysis  of,  516 

artificial  synthesis  of,  465,  466 

blue,  495 

carmine,   504,   509 
synthesis  of,  510 

commercial  varieties  of,   509 

disulphonic  acid,   504 

extract,  504 

monosulphonic  acid,  504 

plant,  treatment  of,  494 

printing,   552 

purple,  509 

salt,  466 

substitute,  458,  511 

vat  dyeing,  536 

white,  495 
"  Indigo  pure,"  466 
Indoines,  458 
Indophenol,    460 

white,   460 
Indulines,  458 
Indurated  fibre,  324 
Infusion  process  of  mashing,  212,  213 
Ingrain  colors,  464 

red  dyeing,  540 
Insect  wax,  58 

Invert  sugar,  determination  of,   174 
Invertase,  204 
Iodine  absorption  of  fats,  89 

compound  with  starch,  187 

number,  298 
Iron  mordants,  533 
Isinglass,   377,   381 

adulteration  of,  382 
Isopurpurin,  467 


594 


INDEX. 


Jaggery   sugar,    167 

Japan  wax,  56 

Japanese   lacquer,    111 

Japans,    121 

Jordan  beater  for  paper  pulp,  320 

Juice-warmers,    152 

Jute  bleaching,  528 

dyeing,  541 

fibre,  307,  314 

statistics   of,   340 


K 

Kaiserschwarz,  511 

Kalle's  artificial  indigo,  466 

Kaseleim   pulver,    293 

Kauri  resin,  108 

Kephir,  292 

Kerm.es,    492 

Kerosene,   32 

Ketones,  448 

Kindt's  test  for  vegetable  fibres,  310 

Kino,  497 

in  tanning,  359 

red,  497 
Kinb'in,  497 
Kips,  357 
Kirschwasser,  252 

Kjeldahl  method  for  nitrogen,  294 
Knoppern,   360 
Koettstorfer's  method,  297 
Koumiss,  291 
Kraft  paper,  313 
Krapp,  489 


Lac  dye,  492 

resin,  108 

Laccainic  acid,  492 
Lacquers,   103,   111,  114 
Lactometer,  use  of,  293 
Laevo-pinene,  105 
Lager-beer,   218 

Laming  gas  purifying  mixture,  404 
Lamp-black,    31 
Lanolin,  57 
Lard,  56 

cheese,  287,  291 

oil,  56 

Lead   acetate,    393 
Leather,  analysis  of,   375 

and  glue,  bibliography  of,  382,  383 

industry,  statistics  of,  383 
Leed's    scheme    for   soap   analysis,    93 
Lees  of  wine,  234 
Leguminous   starches,    185 
"  Leuco  "   compounds,   456 
Levulose,    manufacture    of,    192 
Light  oil  of  tar,  415 
Lignite,  398 
Ligroine,  32 


Lillie  evaporator,  144 
Lima  oil,  refining  of,  25 

wood,  488 

Limburger  cheese,  290 
Lime  and  copperas  vat  for  indigo,  536 

sucrate  process  for  molasses,  162 

use  of,  in  defecating  sugar  juice,  141 
Liming   of   hides,   361 
Linen-bleaching,  527 

dyeing,  541 
Linoleum,   116,  122 
Linseed  oil,  54 

caoutchouc,    122 
varnishes,  113,  120 
-Liqueurs,  253 
Liquid   adhesive   plaster,    332 

glue,  381 
Litho-carbon,   18 
Litmus,    496,   511 
Llama  fibre,  343 

Loading  material  for  paper-pulp,  321 
Logwood,  495 

blue  on  wool,  542 

dyeing,  536 

extracts,  510,  513 
Lokanic  acid,  497 
Lokao,  497 
Lokaonic  acid,  497 
Lokaose,  497 
Long-stapled  wool,  341 
Low  wines,   244,   249 
Lubricating  oils,  32 
Lunge's    bleaching   process,    526 

nitrometer,   94 
Lupulin,  209 
Lustre  wools,  341 
Luteolin,  493 
Lyddite,  85 

M 

Maceration  process  for  sugar-beets,  151 
Machine-made  paper,  322 
Maclurin,  492 
Madagascar-wood,  489 
Madder,  489 

bleach,  524 

flowers,  490 
Magdala  red,  458 
Magenta,  457 
Maize  oil,  55 
Malachite  green,  457 
Malt,    analysis   of,    219,    220 

composition  of,  208 

liquor  industry,  208 

substitutes,  215 

vinegar,  manufacture  of,  269 
Maltha,  17 

Malting   and^  brewing,    bibliography   of, 
273 

process,  210 
Maltodextrine,  187 
Maltose,   manufacture  of,   192 

properties  of,  196 
Manchester  yellow,   459 


INDEX. 


595 


Mandarin,  462 

Manganese   bronze   styles,    555 

Manila   hemp,   308 

Manufacture  of  vinegar,  bibliography  of, 

274 

Maraschino,  254 
Marc  of  grapes,  234 
Marine  soap,  68 
Marseilles  soap,  69 

Martin's  process  for  wheat  starch,   189 
Martius  yellow,  459 
Mash  process,  212 
Masse-cuite,  142,  145 
Mastic,   108 

Mather-Thompson  process,   526 
Mauvein,   458 
Mechanical  malting  apparatus,  211 

wood-pulp,    312 
Melassigenic  salts,   168 
Meldola's  blue,  460 
Melinite,  85 

Melis,  or  lump-sugar,  168 
Melting-point  of  fats,  method  for,  86 
Menhaden  oil,  57 
Menthol,  106 
Mesitylene,   433 
Metanil  yellow,  461 
Methyl    alcohol,    393 

in  wood-spirit,  395 
purification  of,  392 

aniline,  441 

anthracene,  436 

benzene,   434 

eosin,  459 

green,  457 

naphthalene,  435 

quercetin,   493 

violet,  457 
Methylene  blue,  461,  538 

violet,  458,  537 
c-Methyl-quinoline,  446 
Metric  system,  561,  562 
Mica  powder,  84 
Middle  oil,  417 
Milk  analysis,   293 

components  of,  278,  280 

composition  of  different  varieties  of, 
278 

industries,  bibliography  of,  300 
statistics  of,  301 

sugar,  279,  291 
Milling  of  soaps,  73 
Millon's  reagent,  352 
Milly  process  of  saponification,  64 
Mimosa-bark,  360 
Mineral  tanning,  366 
Mitscherlich  method  for  wood  pulp,  312 
Mixing  syrup,  170 
Mohair,  343 
Molasses,  analyses  of,  169 

from  sugar-beet,   159 

from  sugar-cane,  159 
Monochlor-anthracene,   438 
Monohydrated  sodium  carbonate,  530 
Mononitronaphthalene,  440 


Mordanting,  531,  547 

Moric  acid,  492 

Morin,  492 

Moritannic  acid,  492 

Morocco  leather,  366,  370 

Morse  and  Burton's  method,  299 

Mother  of  vinegar,  266,  270 

Mottled  soaps,  69 

Mould  growth  fermentations,  204 

"  Mull-madder,"  490 

Mungo,  351 

Munson  and  Walker's  method,  175 

Muriatic  acid,  530 

Muscovado  sugar,  167 

Must  of  grapes,  224 

Mycoderma  aceti,  266 

Myrobalans  in  tanning,  359 

Myrtle  wax,  56 


N 


Nankin    cotton,    303 
Naphtha  from  petroleum,  31 
Naphthalene,  419,  426,  435 

red,  458,,  464 

sulphonic  acids,  444 

tetrachloride,  438 
Naphthion  red,  461 
Naphthol  black,  463 

blue-black,  464 

sulphonic  acids,  445 

yellow,  459 
S,  459 

a-Naphthol,  443,  452 
a-Naphthol  blue,  460 
a-Naphthol  orange,  462 
£-Naphthol,  443,  452 
/3-Naphthol  orange,  462 
Naphthyl  blue,  458 
/3-Naphthyl-bromide,  438 
/3-Naphthyl-chloride,  438 
Naphthylamine  black,   463 

brown,  462 

sulphonic  acid,  445 
a-Naphthylamine,    442 
/3-Naphthylamine.,  442 
Natural  dye-colors  on  wool,  541 

dyestuffs,  bibliography  of,  519 
reactions  of,  518 
replaced  by  artificial,  o56,  557 
statistics  of,  520 

gas,  composition  of,  14 
occurrence  of,  13 
uses  of,   18,   19 

varnishes,  111,  119 
Neat's-foot  oil,   56 
Nettle  fibre,  309 
Neufchatel  cheese,  290 
Neutral  oils,  32 

red,  458 

New  Zealand  flax,  309 
Nicaragua-wood,  488 
Nicholson's  blue,  457 
Nigrosine,  458 
Nile  blue,  461 


596 


INDEX. 


"Ninety  per  cent,  benzol,"  415,  433 
Nitraniline,  442 
Nitrate  of  iron,   548 
Nitrating  acid,  449 
Nitration  of  cellulose,   328 
Nitrites  in  flour,  265 
Nitroalizarin,  467,  543 
a-Nitrobenzaldehyde,   466 
Nitrobenzene,  439 

manufacture,  449 
Nitro-cellulose,  analysis  of,  332 
Nitro-glycerine,   78,   83 

analysis  of,  94 
Nitrometer,  333 
Nitroso  colors,  439 
Nitrotoluene,  439 
Non-coking  coals,  397 

drying  oils,  55,  59 

lustre  wools,  341 
Nopal-plant,  491 
North  Carolina  pine  tar,  393 
Nutgalls,  360 

in  dyeing,  534 


Oak-bark  for  tanning,  357 

red,   358 
Oil-cloth,   116,   122 

manufacture  of,  116 
Oil-seed  cake,  79 

crushing,  61 
Oils  and  fats,  analysis  of,  85 

physical      and     chemical      con- 
stants of,  585 
statistics  of,  96 
Oil-tanned  leather,  371 
Old  fustic,  492 
Oleomargarine,  284,  2S9,  299 

cheeses,  287 
Oleo-resins,  107 
Olive  oil,  55 
Orange  IV,  461 

G,  462 
Orcein,  491 
Orchil  extract,  506 
Orellin,  493 
Orlean,  493 
Orleans  process  of  vinegar  manufacture, 

267 
Orseille,   491 

carmine,  507 

purple,  507 
Orselline,  506 
Ortho-toluidine,  442 
Osmose  process  for  molasses,  160 
Otto  coke-oven,  405 
Otto-Hoffmann  ovens,  407 
Oxidation   colors,   551 
Oxidized  oils,  81 
Oxyazine  colors,  460 
Oxyazo  dyes,  461 
Oxychloride  of  antimony,  533 
Ozokerite,  occurrence  of,  17 

treatment  of,  27 


Padded  soaps,  70 
Paeonin,  459 
Pale  brandy,  252 

malt,  212 
Palm  oil,  56 
Paper  and  pulp,  statistics  of,  338 

making,  311 

mulberry  fibre,  314 

pulp  testing,  325,  326 

sizing,  321 

washing  machine,  316 
Papier-mache,  324 
Paraffin,   crude,   occurrence   of,    16 

from   bituminous   shales,  29 

oil,  26,  32 

properties  of,  33,  394 
Paraphenylene  blue,  458,  538 
Para-toluidine,  442 
Parchment,   372 

glue,   380 

paper,  324 

Parmesan  cheese,  290 
Pasteboard,  324 
Paste-dyes,  474 

Pasteur's     process     of     vinegar     manu- 
facture, 270 
Pasteurizing  of  beer,  218 

of  wine,  227 
Patent  fuel  (briquettes),  423 

glue,  381 

leather,  371 

Pauly  artificial  silk,  334,  335 
Peach-wood,   488 
Peanut  oil,  56 

Pearl-hardening  for  paper,  321 
Peat,  398 

Penta-nitrate  of  cellulose,  328 
Peptones   from   malt,   209 
Perfumes,  manufacture  of,  111 
Perkin's  violet,  458 
Permanganate  of  potash,  529 
Pernambuco-wood,  488 
Perry   for   vinegar,   267 
Persian  berries,  493 
Persio,  491 

Petiotization  of  wines,  228 
Petrolatum,  27,  34 
Petroleum,  bibliography  of,  48 

Canadian,  15 

ether,  31 

Ohio,  nature  of,  15 

Pennsylvania,  nature  of,  15 

Russian,  16 

statistics,   49 
Phenanthrene,  436 
Phenetol   red,   462 
Phenol,   400,  S418,  443 

dye-colors,    459 
Phenol-phthalein,    459 

sulphonic  acid,  444 
Phenols  in  tar,  tests  for,  425,  426 
Phenyl-anthracene,  436 

methyl-ketone,  448 


INDEX. 


597 


Phenylene  brown,  469 
Phenylenediamine,  443 
Phenylglycerine-o-carboxylic,  466 
Phenyl-glycocoll,   510 
Phlobaphene,  358 
Phloxin,  460 
Phosphine,   465 
Phosphotage  of   wines,   22S 
Photogene,  35 
Phthalamide,  466 
Phthaleins,  447,  453 
Phthalic  acid,   447,   452 

anhydride,  452 
Physical  and  chemical  constants  of  fixed 

oils  and  fats,  585,  586 
properties  of  fixed  oils,  58 
Picene,  437 
Picric  acid,  459 
Pigment  brown,  461 

styles  of  tissue-printing,  551 
Pincoffin,  506 
Pineapple  fibre,  309 
Pine-bark  in  tanning,  358 

tar,  393 

Pinene  of  oil  of  turpentine,  105,  156 
Pinoline,    122 
Pitch  from  coal-tar,  428 
Plastering  of  wines,  227 
Plate  carthamine,  490 

red,  506 

Plumping  of  hides,  363 
Pneumatic  malting,  211 
Polarization  of  sugars,  172 

Polymerizing  of  turpentine  oil,  126 

Polyterpenes,  104 

Pomades,   111 

Ponceau  B,  463 
2R,  462 
3R,  462 
4GB,  462 
4KB,  463 

Poppy-seed  oil,  54 

Porter,   218 

Potassium  carbonate,  530 

Potato  group  of  starches,   185 
mash,  242 
yeast,  260 

"  Poteen  "  whiskey,  253 

Preservation   of   timber,    420 

Preserved  milk,  281,   288 

Press  for  oil   seeds,  62 

Pressure  flask  for  hydrolysis,  198 

Primary  disazo  colors,  463 

Primrose,  459 

Primuline  colors,  464,  541 

Printer's   ink,   manufacture   of,    115 

Printing-paper,  324 

textile  fabrics,  545 

Proof  spirit,  251 

Propiolic  paste,  466 

Prune  pure,  460 

Prune  wine,  230 

Pseudo-phenanthrene,  436 

Puer,  use  of,  366 

Purifiers  for  gas,  403 


Purification  of  water  for  dyeing,  534 
Purpurin,  467,  490 
Pyrene,  436 
Pyridine,  445 
Pyrogallol,   443,   448 

manufacture,   451 
Pyrol  igneous  acid,  393 
Pyrolignite  of  iron,  393 
Pyronine,  458 
Pyroxyline  for  collodion,  331 

manufacture  of,  32Q 

varnishes,  332 


Quebracho-wood  in  tanning,  360 
Quercitannic  acid,  358,  492 
Quercitin,  492 
Quercitrin,  492 
Quercitron,    492 
Quick-vinegar  process,  268 
Quinaldine,   446 
Quinoline,  445,  454 

blue,  465 

red,  465 

yellow,  465 

R 

Raffinade,  168 
Raffinose  sugar,   169 
Rags  for  paper-making,  311 
Raisin  wine,  230 
Ramie  fibre,  308 
Rape  oil,  55 
Ratafia,  254 

Rational  BaumS  scale,  567 
Raw  sugars,  analyses  of,  168 
analysis  of,  172 
refining  of,    148 

Recognition  of  dyes  on  the  fabric,  476 
Recovered  soda  from  paper-making,  325 
Rectified  spirit,  251 
Rectifying  distilled  spirit,  249 
Red  corallin,  459 

dyes,  recognition  of,  on  fibre,  476 

liquor,  532 

oil,  71 

sanders,  489 
Reduced  oils,  19 

indigo  process,  553 
Reeling  of  silk,  348 
Refining  of  vegetable  oils,  63 
Reichert-Meissl  figure,  298 
Reichert's  method,  298 
Rendeinent  or  refining  value,  177 
Rendering  of  tallow,  60 
Residuums,  oil,  26 
Resin  acids,  107 

separation   of,   94 
Resins,  nature  of,  106,  107 

statistics  of,  132 

tests  for,  126,  127 


598 


INDEX. 


Resists  in  calico-printing,  547,  554 
Resorcin,  443 

blue,  461 

brown,  463 

manufacture,  451 

phthalein,  453 
Retene,  437 
Retting  of  flax,  305 
Revivifying  bone-black,  164 
Rhamnetin,   493 
Rhigolene,  31 
Rhodamine,   460 
Ripening  of  cheese,  287 
Rice  group  of  starches,  185 
Rincage,  346 
Rocelline,  462 
Rock  asphalt,  17 
Rolls  for  sugar-mills,  138 
Roquefort  cheese,  290 
Rose  Bengale,  460 
Rosin,  108 

grease,  122 

oil,  122 

in  mineral  oils,  127 

soaps,  69 

spirit,  122 
Rosolic  acids,  459 
Rothholz,  488 
Roxamine,  463 
Rubber  substitute,  123 

vulcanization  of,   117 
Ruberythric  acid,  490 
Ruffigallol,  468 
Rum,  252 

Russia  leather,  371 
Russian  glue,  381 


Saccharomyces,  205,  206 
Safflower,   490 

carmine,   490,   506 

extract,  506 

red,  506 
Saffrosine,  459 
Safranine,  458,  537 
Sago  group   of  starches,    185 
Sal  soda,  530 
Salicylic  acid   in  beer,  223 

in  wine,  238 
Sandal-wood,  488 
Santalin,  488 
Santa-Martha-wood,  488 
Sapan-wood,  488 
Saponification  equivalent,  89,  297 

of  fats,   64 

value  of  fats,  88 
Sarco  asphalt,  28 
Sawdust,  distillation  of,  388 
Saxony   blue,   509 
Saybolt  tester  for  oils,  39 
"  SchafFer's  acid,"  445 
Scheelization  of  wines,  229 
Schenk-beer,  218 


Schiedam  schnapps,  253 
Schlempe,  171,  255 
Scrap  rubber,  working  of,  119 
Scrubber  for  gas  washing,  403 
Sea-island  cotton,  303 
Seal  plushes,  545 
Sealing-wax,  121 
Secondary  disazo  dyes,  463 
Seed-hairs,  302 
Seed-lac,   108 
Self-raising  powders,  260 
Semet-Solway  coke-ovens,  407 
Sericin,  346 
Sesame  oil,  55 
Sesquiterpenes,    104 
.  Shark  oil,  57 

Sheibler-Seyferth  elution  process,   162 
Shellac,  108 
Shoddy,  350 
Short-stapled  wood,  341 
Silent  spirit,  246,  251 
Silk  bleaching,  529 

cocoons,    344 

conditioning,  348 

dyeing,  544 

fibre,  344,  351 

glue,  346 

scouring,  349 

statistics   of,   355 

worm,  development  of,  344 
Simon-Carve's  coke-oven,  405 
Sisal  hemp,  308 
Size  glue,  380 
Sizing     materials,     recognition     of,     in 

paper,   327 
Skimmed  milk,  283 
Sludge  acid,  25 
Smokeless  powder,  85 
Soap  analysis,  scheme  for,  93 

coppers,  68 

frames,  71 

making,  66 
Soaps,  classification  of,  81 

composition  of,   82 

in  bleaching  operations,  530 
Sod  oil,  370,  372 
Soda  ash,  530 

crystals,  530 

process  for  wood-pulp,  313 
Sodium  chloride  in  dye-colors,  469 

peroxide,  530 

sulphate  in  dye-colors,  469 

zincate,  548 
Soft  soaps,  82 

water,  535 
Solar  oil,  35 
Soldaini's  solution,  175 
Sole-leather,  361,  370 
Solid  green,  457 
Soluble  blue,  457 

indigo,   504 

starch,   193 
Solvent  naphtha,  417 
Sorghum  cane,  analysis  of  juice  of,  137 

plant,  134 


INDEX. 


Soudan  brown,  461 

G,  461 

Souple  silk,  349 

Soxhlet  extraction  apparatus,  85 
Specific  gravity  tables,  566 
Sperm  oil,  57 
Spermaceti,  57 
Spindle  oils,  32 
Spirit  production  of  the  world,  271 

soluble  blue,  457 

varnishes,  115,  121 

vinegar,  271 
Spirits  and  distilled  liquors,  bibliography 

of,  274 

Sprengel  specific  gravity  tube,  86 
Stannate  of  soda,  532 
Stannous  chloride  as  mordant,  532 
Stannic   chloride   as  mordant,   532 
Starch    and    products,    bibliography    of, 
201 

composition  of,  186,  195 

extraction  of,  from  corn,  188 
of,   from  potatoes,   189 
of,  from  wheat,  189 

method  for  analysis  of,  197 

statistics  of,  202 
Starches,  classification  of,   185 
Steam  distillation  of  essential  oils,  125 

styles  of  tissue-printing,  549 
Stearic  acid  manufacture,  74 
Steffen's  substitution  process,   162 
Sthenosizing,   336 
Stick-lac,  108,  492 
Stilbene,  436 
Stockholm  tar,  393 
Stoddard  tester,   42 
Stout,  218 

"  Stoving  "  of  woollen  yarns,  528 
Straw  for  paper-making,  313 
Strength  of  tanning  infusions,  determi- 
nation of,  372,  373 
Stripping  of  silk,  349 
Strontium  process  for  molasses,   163 
Styles  of  tissue-printing,  548,  549 
Substantive  cotton   dyes,  464 

dyeing,  531 

Sucrates,   analysis  pf,   182 
Sucrose,  determination  of,  172,  174 
Sugar  beet,    134 

analysis  of  juice  of,  137 
composition  of,   135 

beets,  analysis  of,  134 

cane,  analysis  of  juice  of,  136 
composition  of,  133 

canes,  analysis   of,    133 

coloring,  manufacture  of,  194 

maple,  136 

of  lead,  393 

production  of,  from  sugar-cane,  137 
statistics  of,  183,  184 

yielding  materials,  133 
Sugars,  analysis  of,  176 
Sulphanil  yellow,  464 
Sulphanilic  acid,  445 
Sulphate  of  ammonia  statistics,  432 


Sulphate  of  magnesia  in  dye-colors,  469 
process  for  wood  pulp,  313 

Sulphindigotic  acid,  504 

Sulpho-acetate  of  alumina,  532 
ricinoleic  acid,  80 

Sulphonating,  454 

Sumach  in  tanning,  359 

Sunflower  oil,  54 

Sunn  hemp,  308 

Surface  fermentation,  205 

Sweet  wines,  231 

Swelling  of  hides,  361 

Swenson  evaporator  for  black  liquor,  325 

Sylvestrene,  105 


Table   of   artificial    dye-colors   replacing 
natural  dyes,  556 

of    reactions    of    natural    dyestuffs, 
518 

of    specific    gravity    figures,    degree 

Baume'  and  degree  Brix,  570 
Table   of  weight  and   volume   relations, 

577 
Tables  for  determination  of  temperature, 

562 
Tabular  view  of  beet-sugar  working,  157 

of  production   of   sugar  from  cane, 

139 

Tagliabue  tester  for  oils,  39 
Tallow,  57 

extraction  of,  60 

oil,  57 
Tannin  as  mordant,  553 

containing  materials,  357 

determination  of,  374 

in  brandy,  256 

in  wines,  238 
Tanning  extracts,  reactions  of,  373 

liquors,  363 

of  sole-leather,  diagram  of,  364 
Tar  from  Otto-Hoffmann  coke-ovens,  408 
Tar-stills  in  petroleum  refining,  23 
Tartar  emetic  as  mordant,  533 
Tartrazin,  464 
Tawed  leather,  371 
Tawing  processes,  366 
Temper-lime  in  sugar  juice,  144 
Temperature   effects    of,   on   distillation 

of  coal,  399 
Terebene,  106 
Terpenes,   104 
Terpin  hydrate,  106 
Terpineol,  106 
Terra-firma-wood,  488 
Tetrabrom-fluorescein,  459 
Tetranitrate  of  cellulose,  *328 
Theory  of  tanning,  356 
Thermometer  scales,  comparison  of,  563 
Thiazines,  461 
Thick-mash  process,  212 
Thin-mash  process,  212 
"  Thirty   per  cent,   benzol,"  434 


600 


INDEX. 


Thymol,  106 
Tin  crystals,  532 

mordants,  531 

spirits,  532 
Tissue-papers,   322 
Toddy,  251 
Toilet  soaps,  83 
Toluene,   434 

sulphonic  acid,  444 
Toluidine,   442 
Toluylen  red,  458 
Tournesol,  496 
Train  oil,  57 
Transparent  soaps,  83 
Treacle,   169 

Tribromphenol  as  test,  426 
Trinidad  asphalt,  17 
Trinitro-cellulose,  328 

phenol,  459 

toluene,  440 

Triphenyl-methane  dyes,  457 
Triple-effect  vacuum-pan,  144 
Tropseolin  OO,  461 

OOO,  No.  1,  462 

OOO,  No.  2,  462 
Tub-sizing  for  paper,  321 
Turkey-red   process,   539 
Turmeric,  493 
Turpentine  oil,   105 

analysis  of,    125,   126 
varnishes,    115,    121 
Tussur  silk,  346 
Twaddle's  scale  for  liquids  heavier  than 

water,  568 
TwitchelFs  method  for  resin  acids,  91 


U 


Unfermentable  carbohydrates,  197 

Unhairing  of  hides,  361 

Upland  cotton,  303 

Upper  leathers,  365,  370 

Usquebaugh,  254 

Utilization  of  fat,  scheme  for,  67 


Vacuum-pan  in  sugar  refining,  143 
Valonia,  359 

Valuation  of  tar  samples,  423 
Vanadium   in   calico   printing,   552 
Varnishes,  analysis  of,  128 

manufacture  of,   112 

varieties  of,  113 
Vaseline,  28,  34 

Vegetable  fibres,  bibliography  of,   337 
classification  of,  303 

glue,  377 

oils  and  fats,  53 

textile  fibres,  302 
Vellum,  372 
Vesuvine,  461 
Vicuna  fibre,  343 


Vigorite,  84 

Vin  de  raisin  sec,  230 

Vinasse,  171,  255 

Vinegar,  analysis  of,  271 

Vinegar,  manufacture  of,  266 

Violamine,  460 

Violet  dyes,  recognition  of,  on  fibre,  482 

Viscose,  334,  336 

Viscosity   test,   43 

Volatile  oils,  103 

Volume  and  weight  relations,  tables  of, 

577 

"  Vomiting  "  boiler  for  paper  stock,  316 
Vulcan  powder,  84 
Vulcanite,  118 
Vulcanization  of   rubber,    117 

W 

Walnut  oil,  54 

Water  for  dyeing,  534 

Wau,  493 

Weight  and  volume  relations,  table  of, 

577 

"  Weighting  "  of  silk,  544 
Weingartner's  dye-testing  tables,  471 
Weiss-beer,  218 
Weld,  493 

Westphal  balance,  86 
Wetzel  pan,  147 
Whale  oil,  57 

Wheat  group  of  starches,  185 
Whey,  293 

alcohol,  293 

butter,  293 

champagne,  293 

of  milK,  279 

vinegar,  293 
Whiskey,  253 
White  brandy,  252 
White-tanned  leather,  371 
Wild  silks,  346 

Wiley's  method  for  glucose  analysis,  200 
Willesden  ware,  324 
Willow-bark  in  tanning,  358 
Wilson-Gwynne  process  for  fats,  65 
Wine,    consumption    of,    in    the    United 
States,  277 

ferment,  208 

production  of   the  world,   276 

vinegar,  270 
Wines,   analyses   of,   232,   233 

analysis  of,  235 

bibliography  of,  273 
Woad,   495 
Wood,   composition   of,   385 

fibre,  312 

naphtha,    389 

pulp,  recognition  of,  in  paper,  326 

spirit,  393 

purification  of,   392 

tar,  creosote  tests  for,  396 

production  and  treatment,  dia- 
gram of,  390 
treatment  of,  392 

vinegar,  purification  of,  389 


INDEX. 


601 


Wood  paving  specifications,  420 
Wood  turpentine,  106 
Wool,  341,  346,  350 

black,  463 

bleaching,   528 

dyeing,  541 

fat,  342 

grease,  57 

perspiration,  342 

scarlet  R,   462 

scouring,  346 

statistics  of,  354 

yolk,  346 

Worsted  fabrics,  350 
Wort,  preparation  of,  212 

of,    for    spirits,    241 
Wrapping-papers,  324 
Writing-papers,   324 


Xanthophyll,  496 
Xanthopurpurin,  490 


Xanthorhamnin,  493 
Xylene,  435 
Xylidine,  442 
red,  462 


Yaryan  evaporator,  144 

Yeast,  use  of,  in  bread,  259,  260 

Yeast-plant,  205 

Yellow  and  orange  dyes  on  the  fibres,  479 

corallin,   459 

Yield  from  distillation  of  wood,  388 
Young  fustic,  492 


Zapon  varnish,  332 

Zinc  chloride  treatment  of  paper,  324 

powder  vat  for  indigo,  536 
Zucker-couleur,  194 
Zymase,   204 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 
BERKELEY 

Return  to  desk  from  which  borrowed. 

This  book  is  DUE  on  the  last  date  stamped  below. 
MINERAL  TECHNOLOGY  L1BRAR/ 


' 


1954 


LD  21-100m-ll,'49(B7146sl6)476 


YD  07578 


^15803 


rip 

s 

(  ^  (  c 


